Experimental protein malnutrition during gestation and breeding performance of squirrel monkeys,Saimiri sciureus

Abstract

The report summarizes our four year experience with the breeding of squirrel monkeys, a New World species used widely in experimental research. Breeding squirrel monkeys in captivity has hitherto been considered capricious, with success in most instances not exceeding 50%. By a combination of hand picking the animals, housing in a harem-type situation with one male to several females, and sound nutrition, a success rate of 85–91% live births to number of pregnancies has been achieved. The rate of stillbirths and abortions in the group maintained on a well-balanced diet did not exceed 10% of the total pregnancies. This compares favorably with any successful breeding program with Old World monkeys, whose reproductive physiology is relatively well understood. It is clear from our studies that adequate quantities of proteins are essential for optimum reproduction. Among the pregnant animals maintained on a diet containing about 50% of their normal requirements of protein (8% calories from a protein source), the incidence of abortions increases significantly. In this group, the rate of abortions to total pregnancies ranges from 40.5 to 61.5%. The females maintained on a protein deficient diet during pregnancy are so protein hungry that an extruded fetus is a welcome food and no time is lost in devouring all of the placenta and the fetus. This type of cannibalism has never been observed among the mothers maintained on a high protein regimen.