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The breeding cycle in male pigs

  • boar maleBoars reach maturity around 6 months of age although this can depend on feeding levels and management. Usually they are not used for service until 7-8 months old.
  • A boar courts a female by chasing her around, nuzzling her head, flanks and genital area, sometimes drinking her urine. He frequently pushes or leans on her to see if she is approaching standing heat.
  • During this time the boar will urinate frequently, he grinds and chomps his teeth, salivating freely and frothing at the mouth. A lot of the boar pheromone smell that stimulates the female comes via this froth.
  • After his penis has entered, the boar rests on the sow and grasps her with his front legs.
  • The boar’s corkscrew penis (with a left-hand thread) has to lock in the sow’s cervix before ejaculation occurs. Boars produce large amounts of semen (up to 500ml).
  • Copulation and ejaculation consequently lasts a long time compared to other livestock. It can take up to 25 minutes, during which time the boar thrusts and rests, as the sow stands still, with all his weight on her back.
  • So care is needed when mating large old boars with small young gilts. In commercial operations, a mating crate maybe used so the weight of the boar is taken off the female.
  • Treat boars as individuals - handle with care and trim their tusks if neccessary (being careful not to draw blood).
  • Don’t overwork the boar. A boar sow ratio of 1:20 is usual. Four services a week is enough in his first year and then serving 6 times a week is plenty.
  • It’s a good idea for them to mate an old experienced sow for their first service, and use an old experienced boar to mate gilts.
  • After a long layoff of more than a month, a boar may have lowered libido and fertility and may need the stimulus of a sow at peak heat to get him going again.
  • Jealousy can be powerful! Letting a boar smell a sow that has been served by another boar or spreading the ejaculate from another boar along the sow’s back sometimes works.
  • Take the sow on heat to the boar. Otherwise he wastes time claiming the new environment and establishing dominance. Make sure floors are not slippery.
  • Boars need regular exercise to remain fit and not fat. They respond to quiet handling and talk from regular stockpeople. They may not like strangers in their environment so take care.
  • Use a pig board (800mm x 600mm) when moving boars to avoid damage to your lower legs from their teeth if they attack. Even cut tusks can have dangerous sharp edges.
  • Boar mating problems:
    • Serving into the rectum instead of the vagina. Supervision and assistance may be needed. Cull boars that never learn.
    • Boars may be put off in very hot weather. Mate sows in the cool of evening.
    • Persistent masturbation into the sheath. Cull offending boars or consult a vet for surgery on the diverticulum of the sheath.
    • Falling off the sow at the point of mounting and ejaculating on the floor. Provide mounting assistance when needed.
    • Aggression with sows or handlers. Cull aggressive boars.
    • Abnormal penis - the penis is naturally bent so don’t worry unless there are entry problems.
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