University of Missouri Extension

G2503, Reviewed November 2018

Management and Care of the Herd Boar

Mark D. Newcomb, John W. Massey and John Rea
Department of Animal Sciences

Reproductive performance of a herd boar depends upon proper care and management. Boars are frequently neglected, especially newly purchased boars en route and after they are brought home. There are essential steps in the care and management of a herd boar that will help eliminate sources of trouble and give you maximum service.

Care in transporting the boar

Take extra care in transporting the boar to minimize sickness and injuries. Even with good management and care, he should not be used until after a minimum 30-day isolation period. The following points should be observed with all breeding herd replacements:

Shelter and exercise

The new boar should have comfortable quarters, isolated from all other animals and free of drainage from other lots. The following steps should be taken:

Feeding to grow and/or maintain the herd boar

Few practical farm rations are deficient enough in any nutrient to interfere with a boar's reproductive function. However, a boar may become permanently or temporarily sterile if a ration that is deficient in quantity or balance of nutrients is fed over a long period of time.

The tendency is for most breeders to overfeed a boar. This is a wasteful practice that results in overfinish, decreased libido and sluggishness.

The new boar should be fed 4 to 5 pounds of balanced 14 percent ration or 4 to 5 pounds of grain and 1/2 pound of a 35 percent protein supplement. If he is over or under condition during breeding season, this amount may need to be changed to maintain thriftiness and vigor. Young boars in breeding condition usually grow well on 6 pounds of feed during the first breeding season and can be maintained adequately on 4 pounds of feed when not in service.

Health check and care

Most health problems can be controlled by buying boars from herds that are apparently free of disease and parasites. This can usually be determined by careful examination of the herd and premises before buying a boar.

After you get the boar home, isolate him as long as practical — 8 to 10 weeks is best. Your veterinarian is the key to maintaining a healthy boar and herd, and he or she should be consulted and used as needed.

The following are health recommendation for buyers:

Management is important

Proper feeding and management are necessary before and during the breeding season. This includes feeding, housing, health and service capacity. When good management practices are not followed, the performance that you get from a boar is often disappointing.

The boar should be conditioned by increasing his ration to 6 pounds, six to eight weeks prior to the breeding season.

You should make a fertility check at least 30 days before you start using the boar. One of the best ways is to hand mate him to five or six healthy virgin gilts that are scheduled for slaughter. If more than one-third of these gilts return to heat within 28 days after mating, the fertility of the boar might be questionable. He should be examined by someone who is properly trained in the evaluation of boars. The evaluation should include:

When the temperature exceeds 80 degrees, hand mating should be done early in the morning and/or late in the evening. The boar should be fed once a day, preferably after usage.

The sow should be bred at least twice during the heat period, preferably the last of the first day and early in the second day. Research has shown that two services increase conception by 30 percent on the first heat and increase litter size by one pig.

The normal breeding load for boars is difficult to determine because of the variation in libido, aggressiveness and ability of individual boars. The foregoing recommendations are averages based on research and practical observation and should be used only as a guide. Maintain one boar for each two sows weaned on a given day, or stagger weaning in multiple farrowing units to get maximum fertility and grouped farrowing.

Table 1
Recommended breeding age and service of boars with different systems of mating

Age in months Pasture mating Hand mating
7 or less None None
7 to 9 6 to 8 in 21 days 10 to 15 in 21 days
9 to 12 8 to 10 in 21 days 15 to 20 in 21 days
12 to 18 10 to 12 in 21 days 20 to 25 in 21 days
18 or over 12 to 15 in 21 days 25 to 30 in 21 days

Breeding procedure

Hand mating is a more common practice with swine than with cattle or sheep. In fact, it is almost the universal procedure in purebred swine herds, and some commercial producers follow the same practice.

When a mature, heavy boar is to be bred to gilts or when a boar pig is to be bred to big, rangy sows, the use of a breeding crate is recommended. Animals that have been breeding naturally may refuse service with a crate or may breed with reluctance. If a breeding crate is not available, two bales of hay placed one on either side of a gilt may serve as a satisfactory substitute.

Where field mating is practiced with commercial herds, two methods are recommended:

During summer months, you can get best conception rates by allowing the boars in breeding pens from sundown to sunup and out during the day.

Handling boars before and after breeding season

The practice is to run only boars of the same age and size together between breeding seasons, provided they are placed together at a young age and their tusks are kept clipped. Older boars should have their tusks removed each year before the breeding season, or as needed. Bolt cutters, hoof trimmers, or a hack saw are instruments suitable for doing this job. Keeping tusks trimmed may prevent serious injury to the herdsman. It is not unusual for grown boars to become irritable and attack when the opportunity arises.

Patience and good judgment should be exercised in handling the breeding animals, for rough treatment may cause old boars to become vicious or young boars to become so timid that they will not mate readily when needed.

G2503 Management and Care of the Herd Boar | University of Missouri Extension

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