INTRODUCTION - Weebly
INTRODUCTION
Swine management could be described as the sum total of what the farmer do not do which affect the profitability the swine operation.
Even the poorest swine operation could be made successful with good management. Conversely, the very best swine operation could become unprofitable with poor management. It is for this reason that management has been said to be the key to profitable swine operation. The management which is contributed to a swine operation is a key factor in the success of the Feeding Program.
Knowledge of feeding swine is important from an economic standpoint because feeds account for approximately 65-75% of the total cost of producing pork. For this reason every swine producer would endeavour to provide a ration that is both satisfactory and inexpensive.
Therefore, since the modern swine producer is interested in maximum performance, a good feeding program and excellent management is of great importance.
The information contained in this publication does not cover all the details involved in pig rearing. The intention is to provide certain guides towards proper and profitable pig husbandry.
One of, the first considerations in pig farming is System Planning. The first principle of planning is to consider the whole operation.
As you plan, keep in mind the expansion 5-15 years ahead or longer. Consider the flow patterns of three major products -feed, pigs and wash, and handle each with a minimum of labour and expense; bearing in mind that the system must provide optimal environmental considerations for efficient pig growth, and operation comfort.
Breed of Swine
All breeds of swine originated from two genera:-
(a) European wild boar Sus scrofa
(b) East Indian pig Sus vitatus /domesticus
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Zoological classification and comparison of certain domestic species. (Plimpton, R. F., and J. F Stephens, Animals and Science for Man: A Study Guide, 2nd edition, Burgess Publishing Company, 1979)
Some pigs perform better than others, even with the same feeding and management; they will produce more off-spring, grow faster, produce less fat and have less health problems. Feeding and management has the most direct influence on production and the success of the business, but the kind of breeding stock you have can limit what good feeding and management can do.
Pigs like other animals inherit bad or good characteristics from their parents and ancestors. In herds where stock has been carefully selected for good traits (eg) over several generations there is a greater chance of finding gilts or a boar that are better than average.
Good breeding stocks with superior traits are essential to the pig industry. The major breeds of swine are classified into two groups – Bacon type and Meat type.
Bacon Type Meat type
Yorkshire/ Large White Hampshire
Landrace Duroc
Lacombe Spotted Poland China
Chester White
Berkshire
The breeds commonly found in Jamaica are Duroc, Hampshire, landrace, large white.
Large white and Land-race are more likely than other breeds to have excellent productive traits such as litter size, milking ability and conception rate, but unless careful selection is practiced t o prevent weak feet and legs, and lower quality of pork cuts.
Duroc and Hampshire are more likely than other breeds to have a high rate of gain, strong feet and legs. Lean, low fat pork cuts but poor productive traits.
A brief description of the more successful breeds in the industry in Jamaica is as follows:
1. Large White/Yorkshire
The Large White or Yorkshire is one of the older English breeds which was introduced locally many years ago. It is white in colour (occasionally one or two black spots) and therefore like all other white breeds is susceptible to sun scald. Other identifying features are its erect ears, and long face. It is of medium body length and the flashing is quite firm. It is reputed to have good mothering ability although individuals have been observed locally to develop a lack of milk at farrowing. It is generally accepted as a good breed for crossing in a market hog operation.
2. Landrace
This is another breed which is white in colour but can be distinguished from other breeds by its extremely long length (it has more ribs than other breeds), its flopped ears and deep sides. The pig originated in Denmark for bacon production several years ago. It has been used in several parts of the world for cross - breeding to take advantage of those feature already mentioned. The land-race has less fat on average than other breeds -a feature which can be usefully incorporated in a programme to produce hogs for meat production.
3. Hampshire
This breed has a more recent history than either of the two, breeds mentioned earlier and was developed in the U.S. especially for the meat market. It is readily distinguished from other breeds being black in colour with a characteristic white band which encircles the body at the shoulder region. Sometimes this white belt includes the front feet. The ham are more rounded and filled than other breeds, the flesh is very firm and the proportion of
meat to fat is extremely high -a feature which the males are capable of passing to their offspring very faithfully. Again, individuals of this breed make excellent crosses for market-hog operations.
4. Duroc
Individuals of this breed are readily identified by their red colour. The breed is most widely known for the ability to put on weight rapidly (good growth rate). The face is short with short ears which flop over the eyes. Because of the rapid rate of gain, many farmers utilize the breed in crossing with other breeds. Others prefer to maintain them in pure strain. .
Other Breeds
There are several newer breeds which have been developed to take advantages of "hybrid vigour", that is the beneficial effect of crossing inbred lines. However before the farmer attempts to utilize any of these new breeds, he should first obtain information on the particular breed in which he has an interest.
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Production Systems
Factors favouring Swine Production
1. Swine excel all other animals except broilers in feed conversion. 3.50: 1 vs. 2.50: 1
2. Swine are prolific. Sows produce up to 12 pigs per litter.
3. Swine excel in dressing percentage 65-80% of live weight, Broilers 80-90% cow 50-60%.
sheep 55-65%
4. Pork is nutritious. (A 3-oz serving of cooked, lean pork will supply the following nutrients in a 2,200 calorie diet. Protein 50 %, phosphorus 25 %, Fe 6 %, Zn 20 % , Riboflavin 22 %, Thiamine 67 %, B12 32 %, Niacin 30 %, Calories 8 %, F 11 %.) (Damron pp460)
5. Pigs are efficient converters of waste and by-product into pork.
6. Since swine are well adapted to the practice of self-feeders, labour is kept to a minimum.
7. Swine require a small investment for buildings and equipment.
8. The pig is adapted to both diversified and intensified agriculture.
9. The initial investment in getting into the business is small and the returns come quickly.
10. The spread in price in market hog is .relatively small.
11. Pigs are unexcelled as a source of farm meat.
12. The pig excels all other farm animals in fat storing ability.
Factors unfavourable to swine production
1. Because of the nature of their diet and their rapid growth rates, pigs are extremely sensitive to unfavourable rations and to careless management.
2. Because of the nature of the digestive tract a pig must be fed a maximum of concentrates and a minimum of roughage.
3. Swine are susceptible to numerous diseases and parasites.
4. Fence of a more expensive kind are necessary in pig raising.
5. Sows need skilled attention at farrowing time.
6. Because of their ‘rooting’ and close grazing habits, pigs are hard on pastures.
Production Systems
There are several alternatives available to a farmer who wishes to enter pig production. Some of which are:
1. Production of Breeding Stock
2. Production of Weaners (feeder pigs)
3. Production of Fatteners or feeder pigs
4. Farrow to finish operation.
5. Integrated Corporate Production
Production for Breeding Stock
This is a highly specialized system that is geared to produce genetically superior breeding stock. (Purebred or controlled crossbred primary products are breeding boars & gilts or show pigs) Success of this type of enterprise is largely dependent on the ability of the operator, to apply the latest selection and breeding techniques that would result in herd improvement.
Production of Weaners
This is a production system where weaned pigs are generally sold at 8 to 12 weeks of age, when they weigh 35- 50 lbs. this type of enterprise is recommended for the farmer who:
1. Can provide dry, warm facilities for farrowing.
2. Has adequate and competent labour who can handle the important detetai1s of breeding, farrowing and record keeping.
3. Is sanitation minded, 1ikes to work with and properly care for sows and nursing pigs.
4. Has limited feed available.
5. Realizes this type of enterprise can be profitable but only if top quality pigs are produced consistently, and at a high level of production per sow.
Production of Fatteners (Feeder pigs finishing)
This involves feeding weaners to market weight (220-260lb). The source of weaners is very important because the health and performance of the pigs will largely determine the profitability of this type of enterprise. This type of system lends itself to automation and is recommended for the farmer who:-
1. Likes to feed and manage pigs of this size and age.
2. Has sufficient feed available to feed pigs through to market.
3. Has a good knowledge of nutritional requirements and good feeding practices.
Farrow to Finish Operation
This involves keeping a herd of sows and feeding the offspring to market weight. This type of operation is very desirable because control over diseases and carcass quality can be more rewarding and set backs in growth due to moving pigs from farm-to farm are minimized. However a combination of the skills required for the previous two systems' is necessary to maximize profits.
Integrated Corporate Production: This is the only growing (expanding) segment of the swine industry. Integrated operations can generally be described as farrow to finish and most often have their own seed stock production as well. The different phases of the operation are usually located on different sites. For instance several brood sows may be found in close proximity to each other, but far enough apart that biosecurity measures between the facilities are easily handled. Nursery facilities for just weaned pigs are commonly found on the same site or at a site close by. However, when the pigs are ready for finishing for market, they are taken to another site, which may be company owned facility or a contractor. (Damron pp440)
SELECTION OF GILTS
Select gilts to be retained for the breeding herd at five to six months of age or when they weigh 200 lb or more. Separate from the market herd and grow them out on 4 to 6 lb of a balanced 14% to 15% protein ration.
CRITERIA FOR HERD REPLACEMENT
Gilts selected for herd replacements should meet the following criteria:
(1) Select gilts that do not have any hereditary defects or from lines that do not have a history of hereditary defects.
(2) Twelve or more prominent teats and from sow lines that are noted milkers.
(3) From lines and or families with high fertility rate noted for large litters and early sexual maturity.
(4) Large frame, structurally correct individuals, with quality bone and proper set to feet and legs.
(5) Healthy individuals from healthy good sows.
(6) Gilts should indicate a rapid rate of gain and have good feed efficiency.
(7) Lean with ample muscling.
(8) Where possible, utilize litter mate and sire records.
Gilts should be fed a balanced ration such that they will meet their genetic potential at breeding time and weigh approximately 220 to 280 lb without being overly fat (6 to 8 months of age).
Breed gilts during their second or third heat period (6 to 8 months). They should be bred on first day heat is observed and rebred 12 to 24 hours later if possible.
(1) In a commercial herd, double mating (best to use two different boars) may be employed. Research indicates an increase in litter size by approximately 1 to 1 1/2 pigs per litter by following the practice of breeding a second time 12-24 hours after the first service.
(2) In a purebred herd, use the same sire for the second breeding.
(3) Sows can be bred in the post weaning heat if pigs are weaned at 3 weeks of age or older and the sow is not in too thin a condition.
(4) Boars should be approximately seven to eight months old before being used in a breeding herd. The boar is considered to be mature (senior) at 15 months of age or older. The suggested maximum number of services / boar are listed in Table 1.
(5) It is recommended that boars be kept in thin, thrifty condition so that they are able to breed gilts and sows. The weight of boars is controlled by the amount of feed fed. In some cases this may vary from 2 to 6 lb per day.
SUGGESTED SELECTION STANDARDS FOR REPLACEMENTS BOARS
Traits Standards
Litter size 10 or more farrowed 8 or more weaned
Underline 12 or more fully developed, well-spaced teats
Feet & legs wide stance front & rear; free in movement; good cushion to both front & rear legs; equal size toes.
Age at 230 lbs 155 days or less
Feed /gain, boar basis 240 lb of feed /100 lb of gain or less (60-230 lbs)
Daily gain (60-230 lb) 2.0lb / day or more
Back fat ultrasound 0.8 in or less (adjusted to 230 lb)
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1. Snout 5. Cheek 10. Fore leg 15. Loin 20. Rump
2. Face 6. Jowl 11. Dew claw 16. Side 21. Ham
3. Eye 7. Poll 12. Pastern 17. Belly 22. Rear leg
4. Ear 5. Neck 13. Toes 18. Fore flank 23. Tail
9. Shoulder 14. Back 19. Rear flank
SYSTEMS OF BREEDING
There is no one best system of breeding or secret of success for any and all conditions. Each breeding program is an individual case. The choice of the system of breeding should be determined primarily by the size and quality of the herd, equipment available, finances and skill of the producer and by his ultimate goal.
Purebreeding - A purebred animal is defined as a member of breed which possesses a common ancestry and distinctive characteristics and is either registered or eligible for registration in that breed. Purebreeding is the mating of two purebred animals of the same breed. The purebred producer has the responsibility of producing genetically superior animals for the commercial producer.
Inbreeding - Inbreeding is the system of breeding in which closely related animals are mated. This includes (1) sire to daughter (2) son to dam and (3) brother to sister. Inbreeding is suggested for only highly qualified operators who are making an effort to stabilize important traits in a given set of animals. Intensive selection is needed to reduce the risk of producing undesirable traits in breeding stock when inbreeding is practiced.
Linebreeding - Linebreeding is a mild form of inbreeding in which the degree of relationship is less intense than in intensive inbreeding and is usually directed towards keeping the offspring related to some highly prized ancestor. The degree of relationship is not closer than half-brother half-sister matings or cousin matings, etc. Line breeding is practiced to conserve desirable traits of an outstanding boar or sow line.
Outbreeding- This is the opposite of inbreeding include crossbreeding, species cross, Grading up and outcrossing (more common form) (Cunningham, Taylor and Field)
Outcrossing - Outcrossing is the mating of unrelated animals (4-6 generations Cunningham pp385) of the same breed. The gene pairs are primary heterozygous, although there is a slight increase in homozygosity over time. Homozygosity for several breeds has been estimated at between 10 & 20 %. .
Crossbreeding - Crossbreeding is the mating of two animals which are members of different breeds. There are two primary reasons for practicing crossbreeding (1) Breed complementation (Crossing breeding so their strength and weaknesses complement one another. There is no one breed that is superior in all desired production characteristics there planned crossbreeding programs that used breed complementation can significantly increased herd productivity) (2) heterosis (hybrid vigor) (This is the increased in productivity in the crossed bred progeny above the average of the breed or lines that are crossed (parents). This system is being practiced by the majority of commercial swine producers because of the resulting hybrid vigor which makes possible improved production efficiency. Swine producers can use Duroc boar to increase prolificacy, a landrace boar to increase length or a spotted boar to increase muscling. Other breeds might also used to provide these traits. (Cunningham p 389) NB; Crossbreeding improves many of the traits that have low heritability. Table 2 lists the expected advantages of Crossbreds over Purebreds.
Species cross – Crossing of animals of different species example mule resulted from crossing the Jack of the ass species and the mare of the horse species (Equus assinus* Equus caballus). The hinny is the reciprocal cross of the mule. Goats and sheep have been crossed even though they have different genus (Capra, Ovis) classification. Fertilization occurs but embryos dies in early gestation.
Grading Up: This refers to the continuous use of purebred sires of the same breed in a grade herd or flock. In this situation, grading up is similar to out crossing. The accumulated percentage of inheritance of the desired purebred is 50% (half), 75 % (three-fourth) 84.5 % (seven eight) and 94 % (fifteen sixteen) for four generations. The fourth generation resembles the purebred sires so closely in genetic composition that it approximates the purebred level.
Crisscrossing or two breed rotation - Boars of two different breeds are used in alternate generations. Crossbred sows resulting from this mating are bred back to the breed of the grandsire on the dam side. An example would be cross a Hampshire x Yorkshire sow, Yorkshire boar x crossbred Hampshire x York sow, Hampshire boar x crossbred Yorkshire x Hampshire sows, etc.
Another system of crisscrossing that might be followed would be Hampshire boar x Yorkshire sows - breed 1/2 Hamp 1/2 York sows to another Hamp boar producing 3/4 Hamp gilts which are crossed back to York boars. Boar rotation in this system - 2 Hamps 1 York.
Three breed rotation or triple crossing - This system involves the use of boars of several breeds attempting to capitalize on the strong traits within each breed. An illustration: Hampshire x Yorkshire producing crossbred Hampshire x York gilts crossed with a Duroc boar. The three way cross gilt in turn would be crossed back to a Yorkshire boar and then repeat the system. The attempt here is to capitalize on the muscling traits of the Hampshire, mothering ability of the York and the growth ability of the Duroc or any such combination of breeds which suits the producer's need.
BREEDING PROGRAM
Hand or individual mating of boars, sows and gilts is recommended over field mating where feasible. If pasture mating is practiced, it is recommended that the following be done:
(1) Divide the sow or gilt herd so as to have one boar per group.
(2) Alternate boars in the sow or gilt herd. Use one boar or set of boars one day and another boar or set of boars the next day.
(3) Boars of the same size and age can be run together during the off season. Boars of different ages should not be run together. Holding lots for boars should be constructed out of strong material that will restrain the animal adequately. Build pens narrow and long. To encourage exercise, feed at one end and water at the other. Furnish adequate shade and shelter for inclement weather.
(4) It is recommended that gilts and sows be kept separate during the gestation period.
(5) Sows and gilts may be either hand-fed or allowed access to a self-feeder every third day during the gestation period. Feeding can be controlled by:
(1) Feeding commercial cubes or shelled corn and supplement scattered out over the pasture to prevent boss sows from getting more than their share,
(2) Furnishing individual feeding stalls for greater control, or
(3) By practicing every third day feeding.
When every third day feeding is practiced, one feeder hole per sow should be allowed. Give them access to feed for 2 to 6 hours (depending on sow condition) in every 72 hour period.
Gilts should be acclimated to every third day feeding by starting every other day for a period of ten days and then moving to a third day basis. Gilts should be allowed 2 to 6 hours on a self-feeder out of each 72 hour period. Depending on condition, allow one feeder hole per animal with round type feeders being the most desirable.
The use of individual feeding stalls offers the best opportunity for:
(a) Feeding each sow or gilt to meet their needs.
(b) Elimination of "boss sow" effects.
(c) Reduction in feed wastage.
(d) Close observation of individual animals.
Table 3. Swine Gestation Table (115 Days).
Tables
Table1. Maximum Number of Services Per Boar
| |Hand Mating |Pen Mating |
| | |Per Month |
|Boar |Per Day |Per Week |Per Month | |
|Mature Boar |2 |10 |40 |25 |
|Junior Boar |1 |7 |25 |18 |
Table 2. Expected Advantage of Crossbreds Over Purebreds
| |First Cross |Multiple Cross |
|Boars |Purebred |Purebred |
|Sows |Purebred |Crossbred |
|Pigs |Crossbred |Crossbred |
|Litter size at farrowing |0% |5% |
|Survival |7% |12% |
|Litter size at weaning |10% |20% |
|Weight of ind. pigs at 154 days |11% |14% |
|Total litter wt. at 154 days |22% |30% |
|N.C.S.U. Experiment Station Bulletin 432, May 1967 |
Table:3. Swine Gestation Table (115 Days), If Bred Jan. 1 - April 30
|If Bred |Will Farrow |
|Managing the Basics |
|Estrus Synchronization Estrus onset is influenced by energy balance and nutrition during lactation. Weaning is used as an estrus |
|synchronizing event in swine. When sows go into heat together, and conceive together, they will farrow their piglets together in groups |
|which make all in/all out flow possible. |
|Signs of Estrus |
|The most definitive behavioural sign of oestrus is standing (primary) to be mounted by the boar. |
|Sows in oestrus will often assume this rigid stance, called the lordosis reflex, when pressure is applied on the rump ("back-pressure") by |
|the herdsman. |
|The group-housed sow actively seeks out the boar. |
|The vulva lips are swollen and red with a thin, mucous discharge. |
|Other signs (secondary) of oestrus include: depressed appetite, restlessness, alertness, pacing, grunting, and chomping of the jaws. |
|Estrus Detection Deficient estrus detection is the most important cause of infertility in breeding herds using hand-mating or artificial |
|insemination (AI) systems. Typically, sows are checked for estrus once a day and gilts twice a day. In herds with estrus detection problems,|
|heat checking sows twice a day is recommended. Estrus detection can be improved by observing sow behavior while the boar is given direct |
|contact with the sow. |
|Refractory Sows However, sows and gilts will become fatigued and refractory to boar contact in less than one hour, even if they are in heat.|
|This is due in part to the extreme exertion (isometric contraction) associated with standing heat. Thus, best estrus detection systems do |
|not allow constant boar contact. For estrus detection in the absence of a boar, response to the "back-pressure" test can be potentiated |
|(increase the effectiveness) by sex-odor sprays (ex. Boar-mate) or tape recordings of a boar. |
Factors affecting Litter Size
There is a great deal of variability in the litter size occurring within and between sow herds. These factors are grouped under ovulation rate, fertilization and embryo mortality.
A. Ovulation rate
1. Breed- Yorkshire, Landrace ovulate more eggs.
2. Heritability- Low estimates for litter size.
3. Cross-breeding
4. Puberty- Gilts will ovulate/shed more eggs at the second heat.
5. Age of sow- increase in litter size at fifth litter.
6. Flushing
7. Hormonal control
B. Fertilization Rate
1. Estrus of breeding sow after weaning.
2. Time of insemination. The life of sperm is an average of 24 hours and the life of the egg 6 hours. (See capacitation) If a sow is inseminated too early, the eggs might not be fertilized.
3. Housing- sows and gilts should be grouped according to size and age.
4. Boar. (heat exposure, overweight or over conditioned)
C. Embryonic Mortality (Period of maximal mortality 8-16 days of gestation)
1. Embryo mortality due to uterine disorder.
2. Inbreeding
3. Feed intake. (Too much feed immediately after service)
4. Increasing maternal age
5. Reproductive diseases eg. Leptospirosis, bangs of brucellosis
6. Overcrowding
7. High environmental temperature
(Hafez p270 & other sources)
Causes of Pig Losses before Weaning Percentages
General weakness 26.9
Crushing 19.2
Scours 14.2
Paralysis 10.1
Rickets 5.3
Abnormalities 4.0
Pneumonia 3.3
Anaemia 1.1
Other causes 15.9
Heritability Estimates for Swine (See Taylor p245
Important economic factors such as growth rate, feed conversion, litter size and carcass merit must be taken into consideration when selecting breeding stock. Not all characteristics are inherited to the same degree. Therefore select for characteristics which are fairly highly heritable. Improve the less heritable characteristics by improving your management.
This table illustrates heritability estimates of swine for some of these economically important traits.
Heritability Estimates for Swine
| |Characteristics |Heritability Percent |
|Carcass |Length |60 |
| |Loin eye area |50 |
| |Back fat thickness |40-50 |
| |Percent of ham |50 |
| |Percent lean cuts |45 |
|Performance |Stillbirth |35 |
| |No. of pigs farrowed |10-15 |
| |No. of pigs weaned |10 |
| |Weaning weight of litter |15-20 |
| |Post weaning gain |30 |
| |Feed efficiency |30 |
| |Birth weight |10 |
(Cunningham and Taylor 349 & 246 respt)
Carcass characteristics are highly heritable. This means that a high percentage of superiority of one animal over another is transferred to its offspring. It also means that if you can identify the superior animal you can make fairly rapid progress towards improving these characteristics.
Feed efficiency and weight for age are only moderately heritable characteristics (low 0- 20%, moderate 20-40 %, high > 40%) (Cunningham pp348). You should not expect to make progress as rapidly in these characteristics as in highly heritable ones. Characteristics which measure a sow's performance, such as litter size, birth weight and weaning weight are less readily heritable. Improvement of these characteristics can most easily be secured by improving management practices. PS: H E varies among species example in beef and dairy cattle H E for birth weight is approximately 40% and sheep is 30 %
Artificial Insemination
This is a process by which semen is collected from the male specie processed, stored and then placed in the female’s reproductive tract by unnatural means.
Artificial insemination offers the best of both worlds: It gives the producer the possibility to use the best boars while decreasing the amount of time spent breeding sows, thus allowing more effective use of the producer’s time. With a decrease in the number of boars on the farm, more space and food become available for sows without additional investments.
AI improves the genetic evaluation of the boars making their EBVs more reliable. It has also been demonstrated that AI cuts more than half the average time required to mate a sow or a gilt. As well, it also reduces the manipulations of the boars, which can sometimes be dangerous for the animal handler. Mating with AI is often easier on gilts and young sows that might be intimidated, especially by large boars.
The semen itself must be treated as any other perishable product. Soon after collection, semen quality starts decreasing. Insemination centers prepare the semen in such a way that an excellent quality can be maintained for a few days. The most important rules to follow for semen preservation are:
1. Semen should be kept at 16 to 18 degrees Celsius until used.
2. Avoid any temperature variation during preservation.
3. Gently agitate the samples once or twice daily to prevent the sperm cells from accumulating at the bottom.
In these conditions, semen can usually be kept for 2 to 4 days without a major drop in insemination results.
No matter how good the semen is, no matter how well it is preserved, a sow can only conceive if she is inseminated at the right time. Thus, it is of utmost importance for the success of AI to have proper techniques of heat detection. Most new AI users improve their results in the first three months after introducing AI into the herd, mainly because they get better at detecting sows in heat. The best indicator of heat is the immobilization of the sow to back pressure.
Advantages
1. Maximum use is made of a valuable boar.
2. It makes group farrowing possible without an increase in the number of boars.
3. Older boars may be used to breed gilts, because gilts are not required to hold up a heavy boar at breeding time.
4. The useful life of boars may be extended as a heavy, aged boar will continue to work effectively on a dummy sow after he has become too large and awkward for natural breeding.
5. There is a considerable saving of time if a large number of sows are to be bred (synchronization).
6. Introduction of new blood line without introduction of disease.
7. Wide selection of high quality boars of all breed are available for improvement and cross breeding.
8. Closed herd operation is possible.
APPROXIMATE SPERM PRODUCTION IN SEVERAL SPECIES
Species Average volume (ml) Millions of sperm/ML Potential # of mating / ejaculate
Bulls (Cattle) 2-10 300-2,000 100-600
Ram (Sheep) 0.7-2.0 2,000-5,000 40-100
Buck (Goat) 0.6-1.0 2,000-3,500 15-40
Boar (Swine) 150-500 25-300 15-20
Cock (Chicken) 0.2-1.5 0.5-60 8-12
Tom (Turkey) 0.2-0.8 0.7 30
(Source Cunningham pp269)
FEEDING AND MANAGEMENT OF BREEDING GILTS
Great emphasis should be placed on the feeding and management of Breeding Gilts as these are the intended replacement sows that are expected to form a part of a profitable enterprise. In order to obtain maximum profits emphasis should be placed on reducing energy, and protein intake of breeding gilts. The potential to maximize profit in a farrowing operation may be interfered with by excessive feeding of gilts during pre-breeding, breeding and gestation periods. Gilts that are over fed immediately after breeding or throughout the gestation period suffer greater embryonic mortality, encounter more difficulties at farrowing, and will lose more weight during lactation than properly fed gilts.
Young gilts also need feed to grow and become mature sows. If the ration is inadequate, the sows will be ineffective in maintaining themselves and in producing strong litters. Weak pigs may result. Young sows may remain small or stunted in growth and be poor milkers. The feeding of a balanced ration in adequate amount during pregnancy is a must in profitable pork production.
Therefore, in order to realize maximum profits from a farrowing operation, it will be necessary to feed the gilts in such a manner as to reduce embryo mortality improved condition of the sow in the breeding herd, and assure no harmful effects on offspring development.
Feeding and Management
The age and condition of the gilt determine the amount and kind of a ration which she should receive. Thin gilts (body condition score 1&2) require more feed than do gilts in good flesh (B.C S 3-4). Large gilts need more feed than do small gilts, and young gilts must have more feed per hundred pounds of live weight than mature sows. The state of pregnancy also must be considered. .
Most gilt are full fed a 16% growing and/or a 14% finishing ration up to a weight of 180 to 220 pounds. The amount of grain desired during the gestation period varies with the age and condition of the animal. At this time gilts should be weighed and probed and the superior gilts selected as replacement breeding stock.
The amount of feed required by sows during the pregnancy period varies with the age, condition, and stage of pregnancy. Gilts should be put on a restricted daily ration after selection. A 12% dry sow ration should be limit fed at the rate of approximately 4-5 pounds per gilt daily during breeding and gestation. This ration will supply adequate protein for the developing gilt during this period. Tests conducted in Iowa, Illinois, Ohio, and South Dakota indicate that about 4 pounds of feed per day will result in maximum birth and weaning weights of pig. Ohio tests indicate that sows fed 5 pounds per day became fat. Those fed 3 pounds per day became weak and skinny. The amount of feed necessary will, however, vary with quality of ration, temperature, and condition of the sow or gilt.
The ration best suited to a particular farm must be based upon the kinds of feeds and forages available and the prices of feeds in the community. The key to feed efficiency is the use of high quality, cheap farm-grown feeds, properly supplemented with proteins, minerals, vitamins, and antibiotics.
During gestation gilts can make very effective use of good pasture of such plants as clover and alfalfa or other locally grow crops. Foraging on pastures will also provide some means of exercise that is desirable during the early stages of gestation. Breeding gilts need exercise as inactive, fat gilts rarely produce and raise good litters.
Gilts should have free access to water at all times. Plenty of water should be fed to gilts during pregnancy either in the form of slop feeds, in troughs twice daily, or in automatic waterers. Water is especially important during the summer when the temperature is high.
During the summer months pregnant gilts need shelter to protect them from sun and rain. This shelter should be dry and free from drafts and dust. bred gilts should have 11 to 14 square feet of shelter per head in cold weather and 15 to 22 square feet of shade per head in warm weather.
Age and Weight of Breeding
A farmer may decide that the small litters produced are due to the lack of prolificness in his breeding stock. Usually he is wrong in making this assumption. Small litters are very often a direct result of carelessness in the feeding and management of the herd at breeding time.
Gilts should be bred to farrow when they 7 1/2 -8 months of age if they have been well grown out. The maturity of the gilt is more important than its age. Most gilts which have done well reach puberty and came in heat when they are 5 to 6 months of age, while others may be at 11 to 13 months of age. Therefore the age to breed will undoubtedly depend on the breed of the gilt and other factors affecting its maturity.
Research studies with Yorkshires and Lacombe have shown that 80% of these gilts have regular heat cycle by 7 months of age and that the number of ova released remains constant for at least the first five heats. Producers should attempt to have gilts grown to 240 pounds by 6 1/2 months and breed on the first heat after that time. There would appear to be little justification for allowing mature well-grown gilts to have 2 or 3 heats before breeding in hopes of getting a larger litter. Thus, most gilt will have .produced their first 1itter before they are one year old.
It is better to breed the gilt during the first or second day of the heat period than during the last day (See diagram page 17). Larger litter may result from two services 24 hours apart.
Once gilts are bred, reduce daily feed intake to approximately 4 pounds of 12% dry sow ration until 40 days before farrowing. .At this time increase daily feed intake to 5 ½ lbs. of 14% dry sow ration or nursing sow ration daily.
FEEDING AND MANAGEMENT OF PREGNANT GILTS AND SOWS
The nutrients fed the pregnant sow must first take care of the usual maintenance needs. If the gilt is not fully mature, nutrients are required for maternal growth as well as for growth of the foetus. Quality and quantity of proteins, minerals, and vitamins become particularly important in the ration of young pregnant gilts, for their requirements are much greater and more exacting than those of the mature sow. The aim is to keep the sow fit, not fat.
The gestation feed intake depends on the environmental temperature in which gestation occurs. The most meaningful way of expressing such a requirement is in terms of minimal level of gestation weight gain necessary for optimum reproductive performance.
The amount of gain desired during the gestation period varies with the age and condition of the animal. A gain of 70 to 90 pounds in gilts during pregnancy will allow for the growth of the gilt and her litter. Mature sows should gain from 60 to 80 pounds during gestation. These figures can be reduced somewhat if the litter is to be weaned when from one to three weeks of age. Pregnant first litter gilts gain about twice as fast as pregnant second litter sows. At farrowing first litter gilts will have a weight loss of approximately 35 pounds (weight of litter after birth, fluids).Second- litter sows will lose 40 pounds at birth. Nursing weight loss for 3 week weaning will be approximately 10 pounds on first litter gilts and 30 pounds on second litter sows.
Today more sows are raised under total confinement. Under confinement conditions different systems and types of feed are used. It also makes it easier to control feed intake and there is less injury to the sow due to fighting. The ration fed the sow has much to do with the type of litter which she will farrow. The ration best suited to your farm must be based upon the kinds of feeds and forages available and the prices of these feeds in your community. The key to feed efficiency is the use of high quality cheap farm grown feed, properly supplemented with proteins, minerals, vitamins, and antibiotic.
Feed Requirements during Gestation Period
The amount of feed required by sows during the pregnancy period varies with the age, condition, and stage of pregnancy. Normally the sow will be bred on the first oestrus cycle after weaning. Breed the sow when standing heat is first observed and again 24 hours later. This will result in a better conception rate. Record the breeding date (gestation period 115 days) .At breeding, the sow should be receiving approximately 5 pounds of 14% nursing sow ration daily.
Tests conducted in Iowa, Illinois, Ohio, and South Dakota indicate that about 4 pounds of feed per day will result in maximum birth and weaning weights of pigs. Ohio tests indicated that sows fed 5 pounds per day became fat. Those fed 3 pounds per day became skinny and weak. Limited feeding is recommended especially when environmental temperature is at 50 degrees or above. It is important that the condition of dry sows should be regulated so that they are neither to fat nor too thin at farrowing time. Overly fat sows may have difficulty in farrowing and give birth to weak or dead pigs. Sows that are too thin at farrowing tend to become suckled down during lactation. Thus, one way or another, limited feeding is a must for pregnant gilts and sows. This may be accomplished by adding sufficient bulk; by interval feeding; by group hand-feeding; or by individual feeding. In hand feeding the animal can be fed by hand the right amount of feed daily or self-fed a bulky ration. Either method may be used successfully.
The self-feeding method requires less labour, while hand-feeding usually takes less feed. In self -feeding the proportion of bulky feeds in the ration must be governed by the condition of the sows. Pregnant sows and gilts should receive about 1/2 to 3/4 pound of crude protein each day. It may be hand-fed in supplement or supplied in the self -fed ration. Plenty of water should be fed to sows during pregnancy. Water is especially important during the high temperature.
First 75 Days of Gestation Period
Breeding stock should be given a sow -weaner type feed. 'Slop' feeding is recommended. After breeding, feed intake should be restricted to approximately 4-5 pounds of 12% dry sow ration daily. This ration should be a high energy ration (TDN 75%).Once a day feeding is adequate for bred gilts and sows. Diet can be regulated by using individual feeding stalls or sow tie stalls.
During the early stage of gestation it is desirable to have the sows forage in the pasture. Brood sows need exercise, and if they do not rustle out into the fields themselves, they should be fed at a distance. Exercise is essential to avoid sows becoming fat. Inactive, fat sows f1rrow smaller litters and crush more pigs. Exercise also helps to prevent constipation in Sows at farrowing time. If some of the sows, are in poor fleshing, or if weather, conditions are cold, feed intake will have to be increased. Sows must be relatively free from parasites and be kept under suitable environmental conditions. Sows should be washed with insecticide to remove lice and mites. Gilts and sows should be kept in an area, where the temperature does not fall below 50°F. They also need shade, to protect them from the sun and rain. The house should be dry and, free from drafts and dust.
40 Days Before Farrowing
Approximately two -thirds of' the growth of' the foetus is made during the last month of the gestation period; therefore, this is when the nutrient needs of the sow are the greatest. Again, the increased needs are primarily for proteins, vitamins, and minerals. During gestation, it is also necessary that body reserves be stored for subsequent use during lactation with a large litter and a sow that is a heavy milker, the demand for milk production are generally greater than can be supplied by the ration fed at the time of lactation. Therefore, the daily feed intake should be increased from 4 pounds to approximately 51/2 pounds of 14% dry sow ration, 40 days before farrowing.
3 to 4 Weeks Prior to Farrowing
Vaccines against E. coli scours could be useful if available. This could be given at least 4 weeks before farrowing to ensure the presence of antibodies in colostrums to protect piglets. The breeding stock should also be vaccinated against Swine Erysipelas and Pasteurella annually. Stocks should have a routine warming 3 to 4 weeks prior to farrowing. This will allow the sow to be free of worms prior to entering the farrowing quarters. Faecal examination should be done to determine the amount and kind of worm infestation in the herd.
One-Week Prior to Farrowing
Sows and Gilts should be placed in farrowing quarters one week before she is due to farrow. Farrowing quarters must be properly disinfected before sows and gilts are introduced. The sow and pen should be washed regularly to keep her and the surrounding clean. Spray or dust the sow for external parasites such as lice and mites if necessary.
It is considered a good practice to feed lightly and with bulky laxative feeds from 4 to 5 days before and after farrowing. Dilute gestation ration with 25% bran or oats, one week prior to farrowing. The bran or oats helps avoid constipation problems in the sow at farrowing, feed 51/4 pounds of this ration daily. The animals may be watered at frequent internals before or after farrowing, but in no event should she be allowed to gorge.
3 Days Prior to Farrowing
Sows and gilts should be washed with warm water and soap and rinse with a mild disinfectant. In washing the animals particular care should be taken to remove the small plug of dirt that may be on the end of the teats. Sows and gilts should be placed in farrowing crates or pens to permit them to become adjusted prior to farrowing. The farrowing quarters, should be thoroughly cleaned, disinfected, and allowed to stand idle for approximately 10 days to help break the disease cycle. The farrowing quarters should be free of drafts and warm (55 to 70oF} .A newborn pig chills easily. The use of a heat lamp will overcome this problem.
Farrowing Day
Although most sows do not need assistance at farrowing time it is a good policy to be on hand .Sows become nervous as they approach farrowing time and pile up bedding materials. Most sows farrow within 24 hours after milk develops in the nipples.
The sow requires no feed for 12 hours after farrowing. Provide warm (50 to 60°F) clean water only.
FEEDING AND MANAGEMENT OF NURSING SOWS
The gestation -lactation period is a critical one in swine nutrition. It is now known that the feed and care accorded the broad sow materially affects conception, reproduction, and lactation. The successful producer plans carefully for the practice which will be followed during each of these periods. If he fails to care for the sows properly during any one of the periods, serious losses may result
ASSESING SOWS BODY CONTITION
A critical element of successful swine reproduction is managing sows so they do not gain or lose too much weight or body condition between parities. Maintaining sows in proper body condition throughout their lives can lead to more consistent reproductive performance, but inadequate control of sow body weight and condition can lead to farrowing difficulties, poor rebreeding performance, and high culling rates. In addition, the direct economic impact on annual feed costs of underfeeding or overfeeding sows can be substantial.
Individual operations vary in terms of animal genetics, environmental conditions, and management. Therefore, it is important to monitor sows on individual farms to determine the adequacy of current feeding management practices.
This scoring system can be used to determine individual gestation feeding levels to achieve a target condition score at farrowing.
Sow Body Condition Scoring System
This scoring system uses finger or hand pressure at key reference points on the sow’s body to arrive at a number, or score hence the name “sow body condition score. The points used on the sow’s body are those areas where the only tissue between the skin and bones is fat tissue. These areas on the sow include the ribs, back bone, H bones, and pin bones (Figure 1). By assessing the ease or difficulty of feeling these bones, you can estimate the fat stores of the sow. It is important to rely on more than one of these areas when assessing body condition. Different animals may deposit fat in differing degrees at different locations.
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A condition score from 1 to 5 is assigned to each sow, based on the ease or difficulty of detecting bones at various pressure points. Figure 2 illustrates the physical appearance of sows for each condition score and describes the ease or difficulty of detecting the bones for each score. An approximate level of back fat associated with each condition score is given in Table 1. The goal is for sows to attain a condition score of 3 by mid-to-late gestation and to maintain that score until farrowing. Sows with a condition score of 3 at farrowing will enter the farrowing crate with adequate fat reserves to withstand a heavy lactation, but they will not be so overconditioned that they will experience farrowing difficulties or reductions in lactation feed intake. Sows entering the farrowing house with a condition score of 3 should eat well, milk well, and have a condition score of 2.5 at weaning, resulting in a prompt return to estrus. A realistic goal is to have all sows in a farrowing group with condition scores between 2.5 and 3 at farrowing, with 80% scoring 3.
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Table 1. Relationship between condition score and back fat level.
|Condition Score |Approximate Level of Back Fat (Inches) |
|1 |< 0.6 |
|2 |0.6 - 0.7 |
|3 |0.7 - 0.8 |
|4 |0.8 - 0.9 |
|5 |> 0.9 |
Frequency of Condition Scoring Sows
For best results, sows should be condition scored at mating and at least two additional times between breeding and farrowing. It is often convenient to combine condition scoring with other routine activities, such as pregnancy checking and vaccinations, to save time. A typical procedure is to score sows at mating, on day 30 post-mating when sows are pregnancy checked, and about 80 days after breeding. Condition scores will be more accurate if two people score the sows and the resulting two scores are averaged. When this team approach is used, the same individuals should always score the sows so scoring will be consistent.
It is important to record condition scores so that monitoring the sow’s progress is possible. One convenient way to document a sow’s condition score is to record the score on her information card. Another option is to develop a card similar to that shown in Figure 3 and simply circle the drawing that best represents the sow’s condition at the time of evaluation.
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Number of Sows to Condition Score
It is generally best to condition score each sow individually, especially in herds with no recorded history of condition scoring, those in which sow condition is poor, and in herds that are experiencing reproductive difficulties. Once sow body condition within a herd has stabilized at a desirable level or a feeding management strategy has proven satisfactory, it may be sufficient to establish a condition score monitoring program rather than continuing to score all sows in the herd. For a monitoring program, at least 15 to 20% of the sows in each farrowing group should be condition scored.
Using Condition Scores to Adjust Feed Intake
When using body condition scores to adjust feeding levels for sows, it is important to define an operations base feeding rate. A base feeding rate represents the amount of feed which will allow a sow to gain the proper amount of weight and condition during gestation, assuming she has a condition score of 2.5 at mating and is not subjected to extreme environmental conditions. For most operations, a base feeding rate during gestation of 4.5 to 5 pounds per day of a corn-soybean meal diet is adequate.
During lactation, some sows may lose considerable body weight and condition, resulting in a condition score of lower than 2.5 at weaning. These sows will need more feed than the base feeding rate to achieve proper condition by the next farrowing. Other sows may be over-conditioned at the time of weaning and will need less feed than the base feeding rate to achieve the desired body condition score by the next farrowing.
It is best to identify at the time of mating sows that will require more or less feed than the base feeding level in order to reach the target condition score by farrowing. The advantage of identifying these sows early in gestation is that ample time will be available to get them into proper condition. In general, it is best to condition sows during the first half to two-thirds of gestation so that large adjustments in feeding rates are not necessary close to farrowing.
Table 2 shows some guidelines that can be used to adjust the daily feed allowances of gestating sows based on their body condition score. Keep in mind that these adjustments are only guidelines. Animals on different farms may require more or less feed to achieve target condition scores based on their genetics, environmental conditions, and farm management practices.
Table 2. Guidelines for adjusting gestation feeding level based on condition score.
|Condition Score |Feeding Level (Pounds) |
|1 |Base feeding level + 2.0 |
|2 |Base feeding level + 1.0 |
|3 |Base feeding level |
|4 |Base feeding level - 0.5 |
|5 |Base feeding level - 1.0 |
Farrowing Facilities
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These litters are less than 1 hour old. Note the blue bars running across the sows' sides. The side bars on these crates exert inward tension, so that the female must use her weight to push them apart in order to lie down. This helps prevent the sow from flopping down on the piglets. In addition, the bars must be spaced to ensure access to the udder for the piglets.
Farrowing almost always (all in all out) AIAO so sows are grouped to farrow on the same day. Rooms are sized to accommodate 1 group. The number of rooms is dictated by:
• frequency of farrowing (weekly, semi-weekly, bi-weekly, monthly)
• weaning age.
The number of farrowing groups is dictated by:
• frequency of farrowing
• farrowing interval
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This sow is alert and sitting up. She was moved into the farrowing room about one day before her due date. Note the heat lamp in the crate behind her; the neighbouring sow already has a newborn litter.
Care and Management During and After Farrowing
Some producers maintain that the care of the sow during gestation and the care of the pigs through the first few days of life account for more than one-half the job of raising pigs.
Normally, healthy sows will usually farrow without trouble. If possible, someone should be on hand at farrowing to offer any needed assistance, that is, preventing pigs from chilling by placing them under the heat lamp, or starting breathing in apparently lifeless pigs by removing the membranes from the nose and applying gentle rhythmic pressure over the ribs in an attempt to get the pig breathing.
Some sows will farrow very quickly while there are sows that will take a much longer time. The farrowing of a good sized litter can be completed in about 60 minutes. A long farrowing period will cause more pigs to die or be weakened during farrowing.
Oxytocin may be used to speed up farrowing. However, there are several precautions which should be observed.
1. Oxytocin should not be given until the cervix is relaxed. As soon as one pig is born, then the cervix is relaxed. If oxytocin is given before this it could cause the uterus to be torn.
2. If several pigs have been born, farrowing may be stopped by a pig stuck in the birth canal. The procedure is to reach into the birth canal, after proper cleaning of your arm and feel if it is open. If one pig has been born and the birth canal is open, the drug oxytocin can then be used to speed up farrowing and save more pigs. A person should not enter a sow unless he has been instructed on how to do so properly. The possibility of introducing infections into the sow at this time is great.
Unskilled persons should rely on the assistance of others who know how to do so properly. If there appear to be complications in farrowing, a veterinarian should be contacted. When farrowing is complete, the afterbirth and fluid should be removed immediately from farrowing quarters. The hindquarters and udder of the sow should be wiped clean again immediately after farrowing, if the sow had become dirty with blood, fluids, etc, during farrowing. A clean sow is less likely to infect newborn pigs.
A weight loss of 5 to 10 pounds during the first three weeks of lactation is acceptable for the first- litter gilts. Second- litter sows may lose 25- 30 pounds during the same period. The larger the litter nursed, the greater the weight loss. The normal temperature of the sow is 101o +1 for the week prior to farrowing.
The temperature can increase to 102.7°F + 1.3° just before farrowing, and for 2 or 3 days after farrowing. Normal healthy sows can have a temperature of 104°F during 48 hours immediately after farrowing and no treatment should be initiated on the basis of a high temperature alone. If other signs such as reduced appetite, abnormal milk flow or abnormal discharge from the vulva are present, treatment is indicated. M.M.A. Syndrome (Metritis Mastitis, Agalactia) may occur 1-2, or more days after farrowing. A veterinarian can best advise no treatment. A rectal thermometer can reveal abnormal temperatures.
Farrowing is the most critical time in pig production. The importance of good sanitation, along with common sense and alertness by the operator, is obvious.
Feeding during the Nursing Period
On day of farrowing, sow will eat very little. Normally the sow will be receiving approximately 5 1/2 pounds of 14% dry sow ration containing 25% bran, one week prior to farrowing.
After farrowing, provide the sow with a 14% nursing sow ration. This ration can be fed to appetite in two one -hour feeding per day or self fed. The sow may be fed the same ration the three days after farrowing as the three days before. It is usually best to feed about a half -ration the first day and increase the ration gradually- until she is on full feed. Heavy milking sows should be hand fed for the first week after farrowing. Other sows may be self -fed. Nursing sows can consume 10 to 15 pounds of 14% nursing sow ration daily. As weaning time approaches, feed intake can be cut back to reduce milk flow. Adequate water should be provided at all times. A nursing sow may consume 40 to 50 pounds (4 to 5 gallons) of water daily. There are several problems which may arise during the management of nursing sows. Some sows may fail to produce milk. This may be due to a number of causes such as, run down condition at farrowing time, inadequate diet, or inherited traits. Again mastitis or udder oedema might be present. This leads to tenderness of the udder with a tendency for the sow to prevent the pigs from sucking. The milk supply later dries up. Fatty deposits in the udder, a consequence of faulty feeding during pregnancy can also impede the secretion of milk.
Diets consisting of mainly corn, banana, potato or other root crops, which are too high in carbohydrates and too low in protein will lead to milk shortage. A good lactating sow will produce an average of about one gallon of milk daily during her suckling period. A sow's milk is also richer than cow's milk in all nutrients, especially in fat. Thus, sows suckling litters need a liberal allowance of concentrates rich in protein, calcium, phosphorus, and vitamins.
Sometimes a sow refuses to own her litter, due most frequently to pain or irritation; it is more common in young gilts at first farrow. When this occurs the pigs should be removed for a few hours. Then a few should be placed outside the gate of the pen. Their squealing and desire to suckle might attract the attention of the mother and if she comes to the gate and shows interest, they might be placed with her. If she lies down and let and lets them suckle, the other piglets can be placed with her. However she should be watched for some time until she appears to have completely accepted them. Injectable tranquilizers are available to calm excited animals.
Sometimes a sow will kill her pigs as they are born. This could be due to pain or a deficiency in the diet during pregnancy, such as a shortage of animal’s protein in the ration. It is advisable to fatten such sows for slaughter instead of keeping them in the breeding herd.
Re-breeding Sows
Generally sows will come into heat 5 to 7 days after weaning occurs. Depending on the intensity of the farrowing schedule, sows can be re-bred on the first heat period, or can be passed over to the next period 18 to 24 days later. Sows should be bred when standing heat is observed and again 24 hours later. This will result in better conception rates.
MANAGEMENT THE NURSING LITTER
Farrowing Day
An attendant should be present, if possible, when farrowing occurs. Quick, confident attention will save pigs. Young pigs are sometimes born with mucus membranes or mucus covering their nostrils. This should be removed quickly to ensure breathing. If the newborn pig is not breathing, gentle rhythmic pressure over the ribs may start the breathing process. Shock treatment -immersing the newborn in cold water to start it breathing is also used by some swine producers.
The newborn pig chills easily, coming from womb temperature of 102°F to barn temperature of 70°F or less. The newborn pig should be able to get under heat as soon as possible after birth.
Thorough sanitation must be maintained in the farrowing pen. All soiled bedding and dirt should be removed and replaced with fresh clean bedding. It is important to keep the area dry and clean.
Bleeding Navel
If this is a problem, tie navel. Sometimes the navel cord is long and it is impossible for the pig to move about freely. If necessary, tie the navel cord and cut off about two inches from the body. Then dip the end that has been cut in tincture of iodine solution. The navel should be examined and treated regardless of the length of the cord. It may be necessary to tie the cord if bleeding continues.
Check vitamin K level of sow feed. Feed should contain a minimum of 2 grams of added vitamin K per ton of complete feed.
Navel and Joint Infection
Normally the infection settles in joints, and causes swelling. Prevent infection entering the body through the navel by dipping navel in mild disinfectant. If infection enters the body through skinned knees from the nursing process, check floors for roughness. A rubber mat may help. Some producers use an antibiotic injection to counteract infection from navel and/or skin abrasions.
Colostrum
The newborn pig should be encouraged to nurse as soon as possible to enable it to build up antibodies for greater resistance to infection. Colostrum, the first milk after farrowing, is a good source of antibodies and protein. Each teat should be stripped out to clean the teat canal of foreign matter before pigs are allowed to nurse. This can be done when the sow starts to farrow.
Needle Teeth
Needle or black teeth should\be removed at birth. The c1ipping of needle teeth is a controversial issue. Some producers do not clip the teeth because they believe that the mouth and gums may be injured, allowing infections organisms to enter the body. However, the practice, if done properly, will not cause disease infections. It may even prevent them, because, when fighting, pigs will not be able to inflict wounds upon each other's faces that often permit necrotic and rhinitis organisms to enter the body. If the needle teeth are not removed the pigs will also cut the sow's udder and thus providing sites for possible infection. Clipping should be done with a pair of cutters in such a way that there is a clean, smooth break with no injury to the gums and no jagged edges. Side-cutter pliers should be clean and disinfected before use.
Ear -notching
Breeders of purebred hogs, and many commercial producers make a practice of notching the pigs' ears at farrowing time. It is the most practical method of identifying the pigs of a litter so that the productiveness of a sow can be determined and considered in the selection of breeding stock. All sow -testing programs begin with ear- notching of the pigs. Most producers number the litters in the order in which they are farrowed. The notches may be made using a notching instrument or scissors.
Purebred breeders and swine research specialists may wish to make each pig so that it can be identified by litter number or by number within litter.
Treating Tails
The tails of young pigs may become wet and chapped. Mange or other infections may enter the breaks in the skin and cause the loss of the tails. Although, hogs without tails or with short tails bring the same price at the packing plant as do pigs with tails, buyers of purebreds and exhibitors of pigs prefer animals with tails. The loss of tails can be avoided by keeping the bedding quarters dry, warm and free from drafts, and by coating the tails with vaseline or a medicated salve.
Transfer of Nursing Pigs
Pigs may be transferred to even -up litters. Pigs must receive colostrum milk before transfer is made. Transfer the strongest pigs from the large litters to the small litters. Very small and weak piglets, under 2 pounds in weight, should be killed at birth. A desirable birth weight is from 2 1/2 to 4 pounds.
Anaemia Prevention
Injectable Iron
Usually 1 to 2 cc of injectable iron given in the ham at 2 or 3 days of age will prevent anaemia (follow manufacturers direction).
Oral Iron
10% ferrous sulphate added to a simplified starter in the meal from 1ounce ferrous sulphate and 9 pounds starter can be used to prevent anaemia.
One -half pound of ferrous sulphate starter meal is placed on the floor in the creep area when pigs are 4 days old and twice per week thereafter until pigs are 3 weeks old or can consume dry feed. Newborn pigs obtain an average of 47 mg of iron and require 7 mg daily for normal growth. The sow’s milk contains an average of 1 mg per litter. Therefore it is recommended that the diet of body pigs contain a minimum of 80 mg.
Docking of Tails
Tail Docking reduces the problems of tail biting. Approximately one inch of the tail should be removed with a pair of side cutter pliers when the baby pigs are 2 to 3 days old. Removing only the tip of the tail, or insensitive portion, seems to eliminate tail biting in most herd, although some pork producers prefer to remove the tail close to the body.
Castration
Male pigs should be castrated at 7 to 10 days of age. Castration at this age keeps stress to a minimum. The later they are castrated, the greater the set-back. Under no condition should the pigs be castrated, wormed, vaccinated, or weaned at the same time. These operations should be spaced at two -week intervals.
Unless heat is provided by the use of brooders or heat lamps, pigs should be castrated when the weather is warm. The pen and hog house should be clean, dry, and well bedded.
Before castration begins the scrotum should be washed with a mild antiseptic solution or with soap and water. The sharp knife used in castration and the operator's hands or rubber gloves should be carefully cleaned and disinfected. Usually after the operation disinfectant (iodine) is applied to the area.
At castration time replacements should be identified. Also look out for abnormalities that might disappear as pigs grow older.
Vaccination and Deworming
Vaccination of pigs for cholera has been a common and necessary practice for years. At 6 to 8 weeks inoculate pigs against Swine fever and at 8 weeks against Erysipelas. Additional vaccines are available against E. coli scours, pasteurella, pneumonia and atrophic rhinitis. At 6 to 8 weeks, piglets are wormed and weaned.
Controlling Internal Parasites in Swine
Whether pigs are raised in confinement or on pasture, controlling internal parasites is essential to the overall herd health program. (Recent studies by Tom Kennedy of Research, Inc, Waunakee, WI,) have shown that worm infestation is prevalent on both a farm and individual pig basis. Of the farms examined, 91 percent raised pigs on concrete, wire or slotted floors, but more than 90 percent of all farms were infested with one or more kinds of worms.
Worms reduce growth rate and feed efficiency, and damage tissues, predisposing pigs to infection by other diseases. Economic loss also will be incurred when affected tissues are condemned at the slaughter plant.
ROUNDWORMS (ASCARIS suum)
Eggs of (Large Roundworms) Ascaris suum are small-about the diameter of a human hair and almost invisible. Eggs can withstand severe cold, dryness, most chemical disinfectants and can live at least seven years in soil. The eggs pass from pigs in manure. When they leave the body with the feces, they are in an early stage of development and are infective. Within a few weeks a tiny larva develops inside the egg.
Pigs become infested by consuming food and water contaminated with infective worm eggs. When a pig swallows ascarid eggs, the shells rupture in the intestine and larvae are liberated. The larvae burrow through the intestinal wall and enter the blood stream, which carries them to the liver. From the liver, larvae travel in the blood through the heart to the lungs where they burrow through lung tissue and enter large air passages. The pig coughs and forces worms into the throat where they are swallowed and passed into the small intestine--this time to mature and grow to adults. It takes about four days for larvae to reach the liver, nine days to reach the lungs and 15 days to complete the trip to the intestine. Worms grow to egg-laying adults in about 60 days.
Clinical signs of roundworm infestation are primarily associated with larval migration through the lungs. Pigs have a dry cough, loss of appetite and weight, rough hair coat, increased temperature, and an increased rate of respiration.
Both young and adult worms cause damage. Young worms destroy liver tissue, causing abscesses and scars. In the lungs they penetrate blood vessels, destroy tissue and plug smaller air passages. Damage to the integrity of the lung tissue predisposes pigs to pneumonia. Adult worms in the intestine rob the pig of food, block the gut and excrete substances which interfere with digestion.
Diagnosis is made by microscopic identification of eggs in the feces. Adult worms in the intestine and scars in the liver are seen on postmortem examination.
Whipworms
Trichuris suis, is called the whipworm because it is shaped like a whip. A mature whipworm is 1 1/2 to 2 inches long. It has one of the simplest life cycles known. Eggs are laid in the large intestine and pass from the body in manure. They develop into infective larvae in 21 days. After being swallowed by a pig, the young larvae burrow into the wall of the large intestine. Within a few days, the young worms emerge, attach to the lining of the large intestine and grow to maturity. A life cycle lasts 70-90 days.
Whipworms cause considerable inflammation and irritation of the intestine. Whipworm infestation is characterized by loose stools which in many cases progresses rapidly to a severe, bloody diarrhea. Diagnosis is made by finding worm eggs in the feces or by recovering worms at necropsy (examination after death). If sexually immature worms are causing the damage, eggs may not be found in the feces.
Lungworms
There are three species of Metastrongylus or lungworms. Lungworms are thread-like, white worms up to 2 1/2 inches long. Female lungworms live in air passages in the lungs where they produce large numbers of thick-shelled eggs, which the infected pig coughs up, swallows and passes in manure. Earthworms swallow the eggs, which hatch in the earthworm's intestine and become infective in three to four weeks.
Pigs become infested by eating earthworms which harbor the infective larvae. Lungworm infestation causes coughing and shallow breathing. Hemorrhages occur on the surface of the pig's lungs during early stages of lungworm invasion. Constant irritation by lungworms can bring about consolidation of lung tissue around sites occupied by worms. Tips of lungs become grayish or whitish and very hard in some cases. Secondary pneumonias are common. Pigs infected with lungworms tend to go off feed, become unthrifty and fail to grow.
Diagnosis is made by isolating eggs or larvae from feces or by demonstrating larvae in nasal secretions. Frothy mucus may be found at necropsy. When it is collected in a dish containing water and examined microscopically, the worms are easily observed.
Prevent lungworm infestation by keeping pigs in lots where they cannot contract earthworms. Earthworms thrive in old hog lots in which manure and litter have accumulated, or on permanent pastures and in low fields that receive drainage from higher ground.
Nodular Worms
The nodular worm, Oesophagostomum dentatum, is a small, whitish worm about 1/3 to 1/2 inch long that lives in the large intestine. Worm eggs pass from the pig in manure and under favorable conditions of moisture and temperature, develop to form infective larvae in three to seven days. These larvae can survive up to 10 months in mild climates but will die in cold temperatures. These parasites survive by wintering in breeding stock. The pig will eat infective larvae with feed or water. The worms encyst in the lining of the large intestine and cause nodules to form. This condition is called "pimply gut". Within six to 10 days after infection, the young worms emerge from the nodules and grow to maturity. The life cycle requires 50 to 53 days.
These immature worms can cause loss of appetite, diarrhea or constipation, and anemia. Diagnosis is made by microscopically identifying the characteristic worm eggs in the feces, or by recovery and identification of adult worms at necropsy.
Anthelmintics for Swine
When selecting a dewormer for swine, consider these five factors: (i) efficacy of compound (ii) spectrum of activity (iii) mode of administration (iv) margin of safety (v) cost of treatment. The spectrum of anthelmintic activity determines the number of species affected by the dewormer. Certain swine anthelmintic drugs are highly effective against only one species. If the herd problem involves several species of parasites, use a dewormer that effectively removes many species.
Prevention and Control
Since moisture favors the development of worm eggs into larvae and dryness kills them, reduce moisture to decrease parasitic contamination. Pastures should be well drained and feeding areas should be raised above ground. Many worm eggs can survive for long periods in dirt. Research has shown that ascarid eggs on unplowed pasture lots remained infective for seven years--whipworm eggs can remain infective up to six years. Rotating hog lots will help prevent infestation.
Worm eggs are easily carried by the wind or water and have been recovered from soil on roofs, window sills, and sides of buildings.
Table II. Approved claims of principle dewormers (listed alphabetically by trade name)
| |Types of worms controlled |
| |
|Mixed in feed and fed |
|for 1 to several days, |
|according to directions, |
|to pigs of any age |
|Continuous use in feed, |
|96 g/ton, or a 1 day treatment in feed at 800 g/ton |
|12 g/ton continuous |
|in feed |
|Subcutaneous injection |
|300 µg/kg |
|1 day treatment in feed, |
|water, or oral gel |
|50 mg/lb body weight |
|1 day, in water or feed |
|1.36 mg/lb body weight in feed/day, 3 to 12 day treatment |
|Fed continuous 45.4 to |
|908 g/ton |
| |--- |
|Boar |uncastrated male swine |
|Boar effect |boar exposure to gilts causes earlier onset of puberty with some synchronization |
|Boar power |boar use efficiency |
|Breeding Herd |includes boars and females in stages of gestation, breeding, and farrowing |
|Breeding Soundness Evaluation (male) |assessment of libido, mating ability, and capacity to produce and ejaculate normal semen |
|Bulbo-urethral glands |located at ischiatic arch under penile crura and secrete the tick gel portion of the |
| |ejaculate |
Bacteroides succinogenes & Ruminococcus flavefaciens: 2 bacterias found in intestines of sows that are capable of breaking down fiber
|Cervix |10 to 20cm long with transverse folds which are continuous with the vaginal mucous membrane. Transverse |
| |folds form a "corkscrew." |
|Continuous farrowing |sows (and gilts) grouped in weekly batches, use all in/all out, practiced by larger operations (see periodic|
| |farrowing) |
|Ductus deferens |lacks an ampulla, empties directly into pelvic urethra at seminal colliculus; microscopically, glandular tissue is |
| |present in ampullary area |
|Dystocia |difficulty giving birth |
|Epididymus |tail: dorsal/ head: ventral/ body: cranial + medial making it difficult to palpate due to location |
|Estrus |readiness to mate |
|Evaporative cooling |cooling of the body by loss of the heat required to convert water liquid to vapor |
|Farrowing or Feeder pig |most intensive breeding system; producer has no grow/finish floor and sells feeder pigs |
|operation | |
|Feeder pig operation |breeder sells his grower pigs to a finishing operation to grow them out to market weight |
|Finishing operation |buys feeder pigs and feeds them to 240 to 250 lbs |
|Flushing |increasing energy intake 10 to 14 days prior to estrus to increase number of ova ovulated |
|Foster |practice of placing piglets from dams with too many piglets to feed adequately to mothers with extra |
| |udder space, should occur in first few days after birth |
|Gilt |young female swine, up to and including primiparous (1st litter) females; about 6 months old and 200 to |
| |220lbs |
|Grower pig |pig being grown out to market weight, usually takes about 16 weeks |
|Hand mating |boar is brought to individual female for servicing |
|Hog |generic term, usually applied to growing swine |
|Labia |Female's external lips of the vulva, characteristically become hyperaemic(engorged with blood) and swollen at estrus |
| |(or under the influence of exogenous estrogen.) |
|Limit Feeding |Feeding strategy in which pigs are fed a specific amount of food in a time period. Contrast with free-feeding for a |
| |specific time period. |
|Market weight |240 to 250 lbs |
|Mating |breeding a sow or gilt after the onset of estrus and before ovulation, may include repeated servicings and servicings |
| |by multiple boars and still be considered one mating |
|Meat breeds |used in boar lines in cross-breeding schemes; include: Hampshire, Duroc, Poland China, and Pietrain (pronounced |
| |Peé-a-trin) |
|Mother Breeds |used in maternal lines in cross-breeding schemes; include: Yorkshire, English Large White, Landrace, and Chester White|
|Non-productive Sow Days |days a sow is not lactating or gestating |
|Ovaries |oval shape, mulberry-like appearance due to the multiple follicles/CL's present |
|Parturition |giving birth; specific term for swine is "farrowing" |
|Pen mating |boar is placed with group of sows for servicing (see hand mating and AI) |
|Penis |fibro-elastic with no glans penis; the distal 5-6cm has a counter-clockwise coil which "locks" into the cervix |
| |of the female; the urethral orifice is a small slit 1 cm from the distal end of the penis; the sigmoid flexure |
| |is located cranial to the scrotum |
|Periodic farrowing |twice per year farrowing practiced by smaller operations (see continuous farrowing) |
|Pig |generic term, usually applied to immature swine |
|Pig constipation |pig production exceeds the capabilities of the facility |
|Pork producer |integrated swine producer and meat packer |
|Prepuce |a dorsal prepucial diverticulum is present; has been incriminated in infectious processes (but without proof) |
|Prostate |disseminate portion surrounds urethra, the body lies ventral to the vesicular glands |
|Puberty |time at which first estrus occurs in females, usually at 6 months of age, but depends on breed, environment and |
| |season of the year. Puberty is more gradual in boars progressing over 5 to 18 months of age from onset to full |
| |maturity. |
|Segregated early weaning |SEW, removal of pigs from mother at 10 to 4 days of age in order to facilitate disease management |
|Service |deposition of semen into the cervix of a sow or gilt. may be by "natural" boar or artificial |
| |insemination |
|Shoat |archaic term, usually applied to growing swine |
|Sow |adult female swine |
|Standing Heat |when a sow or gilt is ready to be bred, she will assume a rigid stance and maintain it throughout the |
| |servicing |
|Teats |heritable trait; the number and spacing of teats on boar and sow are important |
|Testes |large and symmetrical; orientation is long axis vertical/oblique |
|Uterus |The uterine horns are short and convoluted when non-pregnant and up to 1.8 m (6ft) in length during pregnancy. The uterine |
| |body is short, about 5cm long. |
|Vagina |The degree of cornification of the epithelium changes with the cycle and pregnancy status, but it is not as |
| |dramatic as in the bitch, and thus not reliable for determining stage of cycle. |
|Vesicular glands |large,paired lobulated glands that occupy the major portion of the pelvic inlet and empty into the pelvic urethra |
| |at seminal colliculus |
|Weaner pig |from weaning up to about 40 lbs |
Methods to reduce PSE and bloodsplash
Observations by the author at slaughter plants and farms all over the United States, Canada, Europe, and Australia indicate that producers are responsible for about 50% of the pale, soft, and exudative (PSE) pork on the market, and packers are responsible for the other 50%. Surveys conducted in slaughter plants in two different countries indicated that PSE levels varied over 100% between different producers.
Genetics is probably the single most important factor contributing to the prevalence of PSE pork today. Some pork-grading systems motivate producers to breed pigs that carry the stress gene. These animals have maximum lean and weight gain (Aalhus et al .,1991). Unfortunately, they also have high levels of PSE. Some of the highest levels of PSE were recorded in hybrid pigs, which had been selected for leanness and rapid growth. The breeding companies have recognized the problem and have taken steps to produce lines that will have lower levels of PSE. DNA testing methods will enable the PSS (porcine stress syndrome) gene to be eliminated (Sellers, 1993).
At one plant, a certain line of commercially available hybrid pigs constituted 10% of the pigs received each day. Ninety percent of the pigs that were dead on arrival or died in the yards came from these hybrids. Genetics has a large effect on death losses (Murray et al., 1998). Genetics is not the sole explanation for differences between producers. A survey conducted at a vertically integrated operation indicated that PSE levels varied 5-10 percentage points among producers who raised identical pigs in identical buildings. Handling, management, and transport also had an effect. Several surveys have shown that pigs transported a short distance will have more PSE compared to pigs transported a longer distance. Observations by the author have indicated that pigs hauled very short distances for under 30 minutes are often more stubborn and difficult to drive at the plant compared to pigs hauled longer distances (Grandin, 1993a). Pigs hauled long distances are more likely to have DFD (dark firm dry) meat because glycogen stores become depleted.
PSE can be reduced by fasting pigs 12 to 24 hours prior to slaughter (Warris and Bevis, 1987; Eikelenboom et al.,1990). Pigs should have access to water at all times. To reduce the possibility of carcass weight loss, a shorter fasting period of 12 hours prior to stunning and slaughter is recommended (Grandin, 1993).
Excitable pigs
There are problems with excitable pigs. The leanest animals with large muscles often have the worst excitability problems. Shea-Moore (1998) found that high lean pigs were more fearful. These pigs often have the worst meat quality problems. Pork from stress gene pigs which are grown to heavy weights is tougher and drier than pork from pigs which are stress gene free (Monin et al., 1999). Excitable pigs are very difficult to handle at the slaughter plant. This creates both meat quality and welfare problems. Handling excitable pigs at 1000 per hour in a single file race is difficult to do quietly. Some plants have installed two stunners to improve handling. Fortunately some of the vertically integrated companies have removed the stress gene from their herds. This has resulted in calmer pigs which are easier to handle. They are now breeding pigs for quality instead of quantity.
Handling of pigs can also be improved by installing a system which eliminates the single file races. The Danes have developed a CO2 stunning system where pigs are stunned in groups. Cattle move very easily through a single file race because their natural behavior while walking from pasture to pasture is to move in single file. Pigs do not have the instinct to walk in single file. When pig excitability increased, problems with single file races increased. When pig excitability is reduced single file races will have fewer problems.
Many excitable pigs are animals that have been raised in confinement (Grandin, 1993). Genetics is a major factor. Observations by the author in identical pig confinement buildings and in the same slaughter plant indicated that changing genetics improved handling. Pigs with a calmer temperament were easier to handle and PSE was reduced. There is a definite need for breeding companies to select pigs for temperament. This is especially important for pigs raised in confinement.
In confinement buildings, producers must provide pigs with more environmental stimulation. Providing confinement pigs with additional environmental enrichment, such as toys and people entering the pens, produced calmer pigs that were easier to drive (Grandin,1989; Pederen,1993). Producers need to eliminate practices such as keeping pigs in darkened rooms. Playing a radio in the building can help get pigs accustomed to sounds. Pigs that have been finished in a pen with a radio playing at a reasonable volume are less likely to be startled by sudden noises.
Producers should walk in the finishing pens every day to get the pigs accustomed to handling. The person should quielty walk through each pen in a different random direction each day to teach the pigs to quietly flow around them. The person should not stand in the pen and allow pigs to chew on their clothes. This trains the pigs to approach and chew instead of driving. Geverink et al (1998) reported that confinement pigs which have been driven in the aisle during finishing were easier to handle. Moving pigs out of their finishing pen one month prior to slaughter improved their willingness to move (Abbott et al., 1997)
Observations by the author have also indicated that raising finishing pigs on plastic or metal floors produces animals that are hard to drive because they do not know how to walk on concrete. Plastic or metal floors work well for young pigs, but during the final finishing phase, confinement pigs should be raised on a concrete surface. Producers must also avoid producing pigs with a high incidence of either hernias or spraddle legs. Both of these conditions have a strong genetic component.
Slaughter plant factors
After pigs arrive at the plant, handling and chilling practices will have a large effect on the incidence of PSE. I estimate that handling practices account for 10%-15% of the variation in PSE, and chilling practices account 20%-40%.
Improvements in handling practices have enabled several plants to ship 10% more pork to Japan. These handling procedures will reduce PSE:
• Schedule trucks to prevent delays during unloading. Heat builds up rapidly in a stationary truck. Do not overload trucks.
• Rest pigs for 2-4 hours prior to slaughter (Malmfors, 1982; Milligan et al., 1996). Trucks must be scheduled to allow adequate resting time.
• Shower with cool water during hot weather (Smulders et al.,1983).
• Handle gently in the stunning chute. Rough handling during the last 5 minutes prior to slaughter increases PSE, because pigs become overheated. Handlers must be taught behavioral principles of pig handling. Over-exertion and excitement shortly prior to stunning increases PSE in stress-resistant pigs that do not have the stress gene (Sayre, 1963; Barton-Gade, 1985).
• Reduce or eliminate electric prods in the stunning area. Stressful handling shortly before slaughter will damage meat quality (Warriss et al., 1990; D'Souza et al., 1998; Van der Wal, 1997).
• Reduced squealing in the stunning area will help reduce both PSE and bloodsplash. Squealing is associated with increased stress and lower meat quality (Warriss et al, 1994). The last five to ten minutes prior to stunning is most critical for reducing PSE.
• Fill the crowd (forcing) pen which leads up to the single file race only half full. Move small groups fo pigs. In group stunning systems the staging areas that leads into the stunning areas should be filled half full. Pigs need room to turn.
• Replace electric prods with other driving aids such as flags, panels, or paddles.
• Eliminate distractions which make pigs balk and refuse to move such as air drafts blowing in their faces, sparkling reflections on the floor, shadows or small moving objects such as chains. If pigs constantly back up, the distraction that is scaring them must be removed (Grandin, 2000, 1996).
Lower temperature
Gentle handling, rest, and showering helps lower body temperature. Pigs that are overheated are more likely to have PSE or DFD meat (Gariepy, 1989). Heat damages the meat, both in live pigs and shortly after slaughter, making proper chilling important. Sometimes carcasses are jammed together or there is insufficient refrigeration. Some managers make the mistake of maximizing pig numbers by overloading the cooler. They are saving a few pennies on numbers and throwing dollar bills away in carcass shrink losses. It is easier to quantify pigs per hour and person hours than shrink loss and customer dissatisfaction. The industry needs to change its mind set and eliminate the "ram and jam" mentality. To succeed in the marketplace of tomorrow, quality must come first and quantity second.
Segmented market
A segmented market causes losses to be passed from the producer to the next person in the marketing chain. A producer who sells pigs live-weight has no motivation to improve quality. Live-weight selling or a carcass marketing system that fails to reward quality are the major causes of quality problems. The producer gets the wrong economic incentives. Some grading systems reward lean, highly muscled pigs with high levels of PSE. The electronic probes currently being used by the packing plants measure fat thickness and the size of the loin, but there is no PSE measurement. This motivates the producer to select breeding stock for rapid gain, leanness, and muscle growth. These selection pressures have resulted in high levels of PSE because pigs carrying the stress gene are kept as breeding stock. The swine industry needs to use an accurate method for measuring PSE so that a PSE measurement can be added to the fat and loin eye size measurements. The producer must be financially rewarded for producing lean pigs with low levels of PSE. Changing the carcass measurement and payment system to include PSE measurement will motivate producers to reduce the incidence of the stress gene in their herds. The bottom line is that the producer has to be financially rewarded for producing quality pork instead of maximum tonnage.
Bloodsplash
Bloodsplash is damage to the meat caused by either small pinpoint haemorrhages or large blood clots in the meat. It is a severe cosmetic defect that affects the appearance of the meat. Haemorrhage problems are mainly caused by problems inside the plant, but nutritional factors such as low levels of selenium and vitamin E may possibly contribute to it by weakening capillary walls. Lean pigs often have more problems with bloodsplash.
These procedures have effectively reduced bloodsplash in many plants which use electric stunning:
• For electric stunning, use an amperage power supply where the amperage remains constant and voltage varies with pig resistance. Old fashioned voltage-regulated stunners allow amperage spikes that damage the meat. Some plants have built their own electronic constant amperage power supplies. These units can lower bloodsplash over 100%. To ensure good animal welfare, a minimum of 1.25 amps must be used to reliably induce a grand mal seizure and produce instantaneous unconsciousness (Hoenderken, 1983). For large market pigs, a minimum of 300 volts should be used and slightly lower voltages can be used for lighter market pigs (Hoenderken, 1983; Gregory, 1988). Some plants have attempted to reduce bloodsplash by reducing amperage to 0.5 amps. This must never be permitted because scientific research has shown that low amperages or frequencies over 800 Hz fail to induce instantaneous unconsciousness.
• Bleeding a pig within 10 seconds after stunning will reduce bloodsplash. Prone sticking systems accomplish this, but older, hanging sticking systems sometimes have intervals of over 30 seconds. Quick bleeding also improves animal welfare because it reduces the possibility of an animal reviving (Hoenderken, 1983; Blackmore and Newhook, 1981).
• The operator must be careful to avoid double stunning and causing the pig to contract more than once (Grandin, 1985/86). Double stunning can be caused by allowing the stunning applicator to slide during the stun or turning on the electricity before the applicator is pressed firmly against the pig. The pig should not squeal when the stunner is applied.
• Worn cords and switches should be replaced. Slight disruptions in electrical continuity will cause bloodsplash. Wet cords can also cause problems.
• Reduce electric prod usage. In a research trial, elimination of electric prods reduced bloodsplash (Calkins et al.,1980).
• CO2 stunning will reduce bloodsplash (Velarde et al., 1999). The disadvantage is that it is expensive to operate and it requires well trained maintenance technicians.
Other Factors
Both PSE and bloodsplash will fluctuate with weather changes. Observations by the author indicate that PSE levels may double during the first 4 hot days of spring. Bloodsplash tends to worsen when temperatures fluctuate. It is very important to take weather into account when new methods for reducing PSE or bloodsplash are being tested. In one study, the amount of bloodsplash reduction benefit provided by new handling and stunning procedures greatly fluctuated, depending on the weather (Grandin, 1988). On some days, it provided great reductions in bloodsplash and on other days, almost no reduction. The procedures must be tested over a period of weeks to eliminate confounding effects of weather.
Bloodsplash can be reduced by the use of CO2 stunning (Velarde et al., 1999). Recent observations in a plant equipped with both state-of-the-art CO2 and constant amperage electrical stunning equipment indicated that PSE and bloodsplash levels were almost identical. CO2 definitely reduces bloodsplash compared to old-fashioned voltage regulated electrical stunning equipment. New CO2 stunning systems could provide handling advantages by eliminating the need to line pigs up in single-file chutes. However, there have been concerns about humaneness (Hoenderken, 1983). Some genetic lines of pigs react very well to CO2 and others may possibly be stressed. The Yorkshire breed reacts very well (Forslid, 1987), but stress-susceptible pigs may possibly be conscious during the initial excitation phase (Troeger and Waltersdorf, 1991). Therefore, CO2 may be an excellent method in a vertically integrated system where pig genetics could be controlled, but animal welfare may be poor for certain genetic types of pigs.
Conclusions
The biggest problem facing some segments of the industry is the emphasis on quantity rather than quality. Producers need to be provided with a marketing system that provides economic incentives to improve pork quality rather than just grow heavier pigs. In the 90's the "mind set" of a large segment of the United States pork industry was commodity based. The entire mind set of the industry needs to change from commodity-based to consumer-based. When this occurs, new procedures will be developed quickly. Fortunately, the industry has become more quality oriented and this has resulted in improvements in pig handling and changes in genetics.
Until this happens, nobody will be motivated to invest the time or the money to change systems.
The primary structures of the female reproductive tract are the ovaries, they have two major functions:
(1) to produce ova, the female germ cells and
(2) to produce the hormones progesterone and estrogen.
Each ovary is surrounded by a thin membrane called the infundibulum which acts as a funnel to collect ova and divert them to the oviduct. The oviduct is about 6-10 inches long and acts as the site of fertilization.
There are two uterine horns. Each is 2-3 feet in length in the non-pregnant sow. They act as a passageway for sperm to reach the oviduct and are the site of fetal development. The uterine body, which is small compared to some other species, is located at the junction of the two uterine horns.
The cervix is a muscular junction between the vagina and uteri. It is the site of semen deposition during natural mating and AI. It is dilated during heat (estrus) but constricted during the remainder of the estrous cycle and during pregnancy.
The vagina extends from the cervix to the vulva and serves as a passageway for urine and the piglets at birth. The bladder is connected to the vagina by the urethra.
The vulva is the external portion of the reproductive tract. It often becomes red and swollen just prior to estrus and this swollen condition is usually more pronounced in gilts than in sows.
The hypothalamus located at the base of the brain secretes gonadotropin releasing hormone (GnRH) which regulates the anterior pituitary gland to secret FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone) into the blood which stimulates the production of the ovarian hormones, estrogen and progesterone, which in turn regulate the reproductive process. Oxytocin is released from the posterior pituitary gland.
Non-pregnant and non-lactating sows and gilts display estrus or standing heat on a regular basis throughout the year. The estrous cycle is normally 21 days and is defined as the time between the onset of one estrus to the onset of the next. The cycle length can range from 18-24 days.
Lactation or the nursing stimulus inhibits the estrous cycle and sows will not, as a rule, return to heat until the litter is weaned. Days from weaning until estrus is influenced by such factors as length of lactation, parity, season and nutritional level, but should range from 4 to 7 days.
The onset and disappearance of estrus and estrus behavior is gradual and there are individual differences among females (see Fig. 3). The primary sign, and most reliable sign, of estrus is "standing" while another sow or the boar mounts. Many females will stand for the "back pressure test" when applied by the herdsperson. A higher percentage of females will respond to the "back pressure test" if there is a boar present. Therefore, use of an intact or a vasectomized boar is an important part of a regular heat detection program. Boars secrete pheromones (odors) in their salivary glands which elicit the standing reflex of the female. Mature boars are superior to young boars in stimulating this response.
Secondary signs of estrus include:
o Red, swollen vulva which is usually more pronounced in gilts than in sows.
o Increased nervous activity.
o Desire to seek the boar.
o Loss of appetite.
o Male-like sexual behavior (pursuing, nosing and mounting other females).
o Change in vocalization (grunts and growls).
o Increase in vaginal mucous (thumb check).
• Sexual Behavior in Swine
• Length of estrus or heat is variable and may last only 12 hours in gilts or up to 60 hours or more in sows. Since the actual time of the onset of estrus is rarely known, it is recommended that a female receive at least two matings during estrus. This helps insure that sperm are present at an optimum time relative to ovulation for fertilization to occur.
• Inseminate a female about 12 hours after the beginning of standing estrus is observed and again 18 to 24 hours after the first insemination. The optimum time to mate will vary from farm-to-farm. Two services as compared to one may increase conception rate and litter size by approximately 10%.
Inverted nipples - These are shown in Fig.1-7. If the teat sphincter cannot be seen at eye level it is likely that such a teat will remain inverted and will not be functional. This is important to appreciate when selecting or receiving a gilt for breeding. Some inverted nipples will become more normal and be functional when the mammary gland develops but when selecting you cannot take the chance.
Note that each teat has two orifices and teat ducts which drain two quite separate mammary glands, front (anterior) and back (posterior).
Oestrus (or heat) - The period during which the sow is receptive to the boar (i.e. will stand to be mated). Usually 1-3 days.
Oestrus cycle - The period from one oestrus to another. 19-22 days interval is normal.
A. The Testes. These primary organs have the dual function of producing sperm cells, and also the male hormone, testosterone. The testis is enclosed in the tunica albuginea surrounded by another tough tunic, the tunica vaginalis. The seminiferous tubules are the site of sperm formation. These in turn empty into collecting ducts, the rete testis, lined with cuboidal epithelium. The supporting connective tissue joins centrally forming a fibrous cord, the mediastinum testis.
B. The secondary sex organs are the ducts and tubes which convey the sperm cells out of the testes and eventually out of the body. They are listed in order in which sperm pass through them.
• Vas Efferentia (ductuli efferentes) - about 12 ducts arising from the rete testis, emerging from the testis and emptying into the epididymis.
• Epididymis - A large tortuous duct outside the testis through which the sperm migrate slowly. It is divided into the head, body and tail. The tail portion is the chief site of sperm storage.
• Penis - The organ of copulation.
C. The accessory sex glands
• Two seminal vesicles - contribute fluid to semen.
• Two bulbo-urethral glands (Cowper's glands) - contribute fluid to semen.
• One prostate gland - contributes fluid to semen.
D. Protective, supporting, and other structures
• Scrotum - the pouch of skin surrounding and protecting the testes.
• External cremaster and tunica dartos muscles - regulate temperature of the testes by moving them closer to or farther away from the body wall.
• Spermatic cord - contains blood vessels, nerves, vas deferens, and muscles associated with the testes; includes the paminiform plexus.
While it is possible to show only 1 testis clearly in this diagram there are two testes, and two sets of ducts carrying the sperm to the urethra. The urethra is a single duct, which also carries urine from the bladder.
The testes are oval-shaped organs 4 to 5 inches in length, 2-1/2 to 3 inches in diameter, with the long axis being vertical. Each testis weighs 10 to 12 ounces in a mature bull. They lie outside the body cavity in a pouch of skin called the scrotum. An important purpose of the scrotum is to provide the testes with an environment which is a few degrees (2-8°C) cooler than body temperature. This cooler temperature is necessary for the formation of spermatozoa. Failure of the testes to descend from the abdomen into the scrotum, associated normally with shortening of the gubernaculum and intra-abdominal pressure, results in a condition known as cryptorchidism. This will cause sterility if both testes fail to descend (bilateral cryptorchidism). Unilateral cryptorchid animals may be fertile, but it is thought that this condition may be inherited, and breeding males possessing this trait should be avoided.
For many years the external cremaster muscle within the spermatic cord has been thought of as the principle thermoregulator of the scrotum, drawing the testes close to the abdomen when cold and relaxing when warm. However, the tunica dartos muscle at the bottom of the scrotum also responds to temperature changes and probably plays a major role in temperature regulation of the testes. It has been shown that this latter muscle is sensitive to temperature changes only in the presence of the male hormone, testosterone. Blood flowing to the testis is cooled by adjacent venous return in a convoluted complex of vessels called the pampiniform plexus, located just dorsal to the testes.
The testes are partially supported by the spermatic cord, which runs from the abdomen and is attached to the testes in the scrotum. This band of tissue, carrying the ductus deferens, blood vessels, nerves and muscles associated with the testis, may be 8 to 10 inches or more in length.
The many convoluted seminiferous tubules in the testis in which the spermatozoa are formed finally straighten and join to form the rete testis. Arising from the rete testis are 12 or more out-going ducts, the vas efferentia, which emerge from the testis and enter the epididymis. The epididymis is a single large tortuous tubule lying on the surface of the testis. Its purpose is to collect and store the sperm while the latter undergo a ripening process. The different parts of the epididymis are referred to as the head, the body, and the tail (caput, corpus and cauda). It is the tail of the epididymis that the majority of sperm are stored. The relationships of these structures are shown in Fig. 2.
[pic]
The Female — Signs of Estrus
• Swollen, reddened vulva (proestrus)
• Vocalization/barking
• Mounting penmates
• Heightened activity level
• Perked or twitching ears
• Sticky, viscous secretion of vulva
• Rigid back and legs; “locked up”
The Boar — Natural Mating
• Nose-to-nose with female
• Nudges female in side/flank
• Noses female's vulva
• Nudges and lifts female in flank
• Attempts mounting
• Mounts; feet drape sides
Stockperson — Simulating The Boar
• Use fenceline boar contact.
• Rub female's side and apply slight back pressure.
• Fist pressure below vulva and check for vulvar moistening (“thumbcheck”).
• Tug or lift the female's flank and rub underline.
• Grip loins and increase back pressure to ensure standing reflex.
• To AI, insert catheter while maintaining stimulatory activity.
• May sit astride female and grip the sides with feet.
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Selection
While there is not room in this paper to discuss it, genetic selection must be recognized as the first criterion used in selecting potential replacement gilts. Regardless of source or age at delivery, however, there are some physical features that producers should use to avoid future problems. Replacement gilts should be selected to have 14 reasonably evenly spaced nipples that appear normal. While most sows will not need all 14 simultaneously, it is common for there to be a loss of functional udder sections, and starting with 14 will allow the sow to have 10-12 functional even if there is some loss of productivity in some sections. Gilts that have difficulty moving are likely to get worse rather than better and should be avoided. Predicting which gilts are likely to have mobility problems in the future is more difficult. Gilts with uneven toes tend to have more feet problems than even-toed contemporaries. Shape and angles of bones can also be important, and while it seems obvious, it must be said that producers should consciously avoid selecting gilts that are splay-footed, pigeon-toed, cow-hocked, sickle-hocked, post-legged, weak-pasterned, or buck-kneed.
Age of boars" - Do not use boars before they are 7.5 to 8 months old.
1 Buy from reliable seedstock producers - known genetics and herd health!
2) Select from the top 50% based on the performance records.
3) Commercial producers:
b) Most genetic changes are made through boar
selection, thus should be willing to pay a premium
for a superior boar?
4) Buy strong boars in a good body condition - .Thin. boars may lack the stamina, and
.fat. boars tend to lack the vigor.
5) Buy boars with sound feet and legs (see PIH-101).
6) Purchase boars (5.5 to 6 months old) at least 60 days before being used.
How Should We Select Gilts?
A. At birth - Ear notch at least twice as many gilts as will be needed, and keep records (birth
date, breed composition, etc.), and may want to foster barrows in large litters because
there are some data indicating that gilts reared in a small group will produce larger litters.
(But, it does not mean that gilts should be selected from small litters though!)
B. At weaning - Remove gilts from a list if their sows did not milk well.
C. Finishing phase - Make a final selection at 175 to 200 lb based on growth rate, backfat,
mammary & skeletal systems and vulva development:
1) Skeletal system - Should be able to move about freely.
2) Mammary system - Should have 12 (minimum!) or more (14?) evenly-spaced, well
developed nipples.
3) Reproductive system - External genitalia should have normal appearances, even
though most defects are not visible!
3. Early Puberty
A. Most gilts reach a puberty at 6-8 mo of age (avg., . 200-220 days).
Selection of my Breeding Animals
After deciding on which breed to use, select good individual pigs to keep.
Boar Selection
• Select a boar before 8 months of age.
• Choose a boar to buy because of the large number of offsprings to which he may transmit his characteristics.
• Ask about the history of the parents of the boar in addition to physical observation.
Before buying/selecting a boar look at its appearance and background.
Appearance:
• Good body constitution.
• Long straight back, deep thighs, strong bones, and full heart girth.
• Sound feet and legs to be able to hold its own weight during mounting
• Good looking, non-inverted, and well placed teats – minimum of 12 teats
• No body defects like hernia (abdominal, scrotal), atresia ani- one testicle not descended into the scrotum (Cryptorchidism), blind or inverted nipples, hermaphrodite, small inside toe.
• Well developed testicles of equal size
Background:
• Must come from a litter of more than 10 piglets
• Weighed more than 12 kg at weaning (8 weeks)
• Dam should have high reproductive performance, be docile, have good feed conversion ratio, and good mothering ability.
• Check health records to know how many times it has been attended to by a Vet and for what condition.
Selection of Gilts/Sows
• It is better to start a pig unit with gilts.
• They should be selected preferably at 4 –5 months of age.
• Crossbred gilts are better performers than purebreds.
• Look at appearance and background when selecting gilts
Appearance:
• Smooth shoulder, clean cut head, strong bones, and full heart girth.
• Sound feet and legs to be able to withstand the weight of the mounting boar
• Seven well developed evenly spaced nipples on each side.
• Long straight back.
Background:
• Crossbred females (Largewhite x Landrace) are preferred to take advantage of heterosis/hybrid vigour
• Gilts should come from sows with very good records on all traits, docility, maternal ability, feed efficiency, longevity.
• Must come from a litter of at least 10.
• No physical abnormalities like hernia, lameness, atresia ani,
REFFRENCES
1. Cunningham, Acker Animal Science and Industry, 6th edition
2. Bundy, Clarence E and Ronald V. Diggins. 1970. Swine production, 3rd Edition,
Prentice –Hall, Inc., Englewood Cliffs – New Jersey.
3. Bunn, A.J., 1972-1974- Ontario
Fact sheet Order No. 72-046, 74-063, 72-045, 74-034, 74-069
4. Jamaica Livestock Association Limited, 1983, Livestock Manual for the tropics. J.L.A. – Jamaica.
5. Boggs D. L & Merkel R .A 1993. Live Animal Carcass Evaluation and selection
6. Damron W. Stephen: An Introduction to Animal Science, Gobal, Biological Social & Industry Perspective.
7. Hafez E.S E. Reproduction in Farm Animals
8. MERCKS & CO .INC. The Mercks Veterinary Manual.
9. Muchette, A. J. Pig Production
10. Taylor. R.E. Thomas. G. F. Scientific Farm Animal Production.
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