Male is Ssexually Mature Two Months

A male is sexually mature around two months of age and may be bred at this time. A female, although fertile at ten weeks, should not mate until she is at least twelve weeks old. Permitting her to breed too early may stunt her growth, cause premature labor, and result in small and weak young.

About the sixty-eighth day of her life, a female guinea pig begins her estrous cycle. She is receptive to a male, or "in heat," the first six to fifteen hours. This cycle repeats itself every sixteen to nineteen days if fertilization does not occur.

The first pregnancy should be before five months of age while her pelvis is still only partially fused. The birth process is then less stressful because of the disunion of the bone.

Guinea pigs may be bred as a monogamous pair - a union of one boar to one sow. Or, you may prefer a polygamous breeding group consisting of several sows to one boar. (The most successful ratio is 3:1.)

Be sure never to have more than one male in a cage as severe fighting may break out. Groups also require plenty of room to prevent ear chewing and trampling of the young.

Guinea pigs are not as sexually productive as their rodent relatives. Their litters are smaller, fewer, and further apart. Surprisingly, it can take several weeks, or even months, for a pair of guinea pigs to mate.

Once impregnated, a sow will swell almost immediately. She carries about sixty-eight days, giving birth to from one to nine pups. The average litter size is three.