Animal Pregnancy is by no means a perfect system but I've had enough PM's and questions about it that I feel its fair to share some things.
*Males can mate with any number of females without penalty.
*The act of mating improves the temperament of both animals. Males slightly more.
*Animals will only mate with something approx 11 tiles or less away.
*If either the male OR female are sick the mating will fail.
*Stillborns are very rare, unless the animal has been cursed by a witch. Then it will be far more likely.
*There is a random chance that the mother will die in child birth for each child. I.E. a larger litter has a higher probability the female will perish in delivery then a smaller litter.
Feel free to use this thread to discuss other aspects of animals and I can help where I find appropriate. I will remind people this is the help forum so no trolling here please.