Bigger litters is every producer’s goal. Certainly there are many causes for a small first litter, just as there are many solutions. MetaFarms offers this analysis:

  • Mating at first estrus. Instead of breeding a gilt at the soonest possible chance, wait until the second or third estrus before mating.
  • High feeding rates during early pregnancy. Producers should reduce the amount fed during early pregnancy to 3.5 to 4.5 pounds a day for a two-week period following the first mating.
  • Inadequate mating procedures or poorly trained artificial insemination technicians. It’s a wise practice to periodically review proper semen-insemination procedures with your AI technicians. It’s just as wise to remind yourself.
  • Improper timing of mating. Make sure that gilts are in a good standing estrus to ensure breeding, and ultimately farrowing success.
  • Stress after breeding. For example, you should not re-group or relocate gilts during the 5th to 30th day after mating.
  • Poor pre-mating nutrition. If you limit-feed gilts, switch them to full-feed for two weeks before they are breed.
  • Lack of indeterminate boar effects. Specifically this means breeding the gilt with a vasectomized boar, dead semen or seminal plasma at puberty. Studies have shown that this practice can increase subsequent litter size.

For more information about litter size and other management recommendations, see SUS Multimedia’s “Reproductive Management of Pigs II” available through MetaFarms at