Breeding pigs

The successful pig farmer always uses good breeding animals. The piglets that are produced must grow fast and produce quality carcasses with a high percentage of meat and a small quantity of fat.

Therefore, when you buy breeding animals, make sure that the pigs come from a farm known to have pigs of good quality and where the management and standard of hygiene are excellent. When buying pigs for the first time, it is advisable to take someone along who has the necessary knowledge and experience.

In the case of a small-scale farm, with 20 or less breeding sows, the following selection and breeding programme can be used:

  • Always buy good (above average) purebred boars. Buy from a farmer of repute who keeps good records so that the performance of the boar and his parents are known.
  • Buy boars from prominent breeds used in South Africa, such as the Landrace and Large White.
  • When buying gilts (young female pigs) for the first time, make sure that they come from a breeder with good pigs and who keeps accurate records. The gilts need not be purebred, but can be crossbred pigs, e.g. Landrace or Large White sows crossed with boars from the other breed.
  • When at a later stage you want to select your own gilts for breeding, it is important to apply strict selection measures and to keep accurate records of growth and feed conversion. If you do not have a record system, it will be advisable to buy replacement gilts.
  • Always buy gilts from the same breeder (farm) and make sure that a breeding plan (policy) is used. Consult an adviser, if necessary. If pigs are always bought from the same breeder it is advisable to let him dictate the breeding policy.

Boar selection, management and use

  • Select boars that are free from defects (see chapter on management).
  • Buy efficient animals that:

- grow faster than average

- have less backfat than the average of the breed

- have eaten less feed than average to reach a specific weight.

  • A good boar will reach 90 kg live weight before it is 140 days old, have a P2-backfat measurement of 15 mm or less, and require only 2,99 kg of feed or less to gain 1 kg in weight to grow from 30 to 90 kg live weight.
  • Buy boars at least four or five weeks before they are used for the first time. This will allow you time to keep them in quarantine and the boars to adapt to the new environment.

Training and use of young boars

Young boars must be carefully supervised to identify possible problems and to make sure that they will not injure themselves when serving a sow for the first time.

Important considerations:

  • The boar must be at least 8 months old.
  • The boar and the sow should preferably be about the same size.
  • The boar should work (serve the sow) in his own pen or in a pen that is familiar to him.
  • The floor of the pen must not be slippery and all obstructions removed.
  • A small sow and not a gilt should be used to train the boar.

Procedures when using a boar:

  • The boar should be in the pen a few minutes before the sow is brought into it so that he can get used to the pen.
  • Stand in the pen with a board ready to prevent the sow to harass the boar or to prevent the boar to harass the sow, if necessary.
  • Do not hurry the boar, let him work at his own time.
  • Talk gently to the boar so that he gets used to your presence.
  • Do not force the boar to mount the sow, but direct him gently to the rear (backside) of the sow.
  • If the sow is well on heat she will not move around the pen too much. Help the boar by letting the sow stand with her head to the corner of the pen.
  • By adjusting the female's tail, attempt to let the boar insert himself.
  • After service, allow the boar to conduct "courtship" under supervision for a few minutes, but do not allow him to remount.
  • If a young boar does not serve the first time, repeat the above procedures every two to three days if possible. Much patience is needed which will eventually be rewarded by having boars which are temperamentally good with sows and people and which have no bad habits.
  • Once a young boar starts to serve (work), he should not be used more than twice a week until he is one year old.
  • Older and full-grown boars (mature) can be used three times a week, but preferably not on consecutive days.
  • On a farm with 20 breeding sows at least two boars must be kept, namely a young boar to serve gilts that come onto heat for the first time, and a full-grown one to serve older and heavier sows. It is also advisable to have a spare boar available at all times.
  • Finally it is important to keep records. The dates when the boar has served a sow as well as the number of the sow that has been served must be recorded so that infertile boars and boars that give small litters can be identified and eliminated.

Replacement of boars

  • Boars must be replaced when they become too large to serve most of the sows on the farm.
  • Boars usually have a maximum working life of between 18 and 24 months. This means they should be replaced when they are 30 to 36 months old.
  • It is very important to keep record of the boars' use so that infertile ones can be detected and replaced as soon as possible.
  • A low sex drive (libido) can also be a problem. Some boars are slow workers and are sometimes reluctant and only now and then willing to work. Attention must be given to these boars so that they can be replaced if necessary.

Gilt (sow) selection and management

Only the best among the young growing female animals on the farm must be selected and kept for breeding. Select breeding gilts from sows that produce large litters with above average growth rate, and carcasses with a low fat content.

The following characteristics should be considered when selecting gilts:

  • Strong, straight legs with large, even-sized claws.
  • Gilts should walk straight and well, and stand up on their claws without falling over at the pastern joints just above the foot.
  • A well-formed vulva and six well-shaped, prominent teats on each side of the belly. The teats should start well forward and be spaced evenly to allow adequate suckling for the piglets.
  • A well-developed ham, good length with light shoulders and head.

Replacement of gilts

If replacement gilts are not available when needed or if they do not comply with the requirements, the gilts should be bought. It is advisable to buy them from the same farm where the boars come from, because in this way the previous owner can advise you on the breeding policy for a small pig farm.

Gilt management before first service

  • Gilts are usually selected for breeding at five to six months of age. The pigs not selected can then be sold as baconers at a live weight of about 85 to 90 kg. The selected gilts are reared to weigh between 120 and 130 kg at seven and a half to eight months of age when they are ready to be served by a boar for the first time.
  • Gilts have to be in a good condition to produce large litters (eight to 10 or more healthy piglets) and should not be too fat when they are ready for mating. Therefore, they should be fed about 2 kg of meal per day from the time of selection until a boar serves them at the age of eight months. This will also ensure that not too much fat is lost during the suckling period and that they are in a good condition after weaning their first litter.
  • Care and management of pregnant and lactating sows (sows with piglets) are discussed in the chapter on management.

Culling of sows

Culled sows must be removed from the farm and sold as soon as possible. It does not pay to keep culled sows on the farm to gain weight before they are sold. As soon as the sow's udder has returned to normal after weaning it is wise to send her to the abattoir. A replacement gilt can then be brought into the herd immediately.

Reasons for removing sows from the herd are usually not known beforehand. Therefore, replacement gilts should always be available so that the number of breeding sows on the farm always remains the same.

Reasons why sows have to be removed from the herd and slaughtered:

Reasons for culling

% of sows to be culled

Not pregnant

17

Failure to conceive at service

12

Do not come on heat

5

Abortions

6

Lameness

12

Poor performance (small litters, etc)

14

Old age

25

Disease

3

Lack of milk

5

 
Sows that farrow regularly and rear large litters (nine or more piglets) and are free of other problems and diseases should rear five to six or even more litters before they have to be removed from the herd. A sow is usually removed from the herd when her litters start to become smaller (two small litters in succession) or when she does not readily come on heat after weaning.