Measuring Productivity in Breeding of Small Animals

Abstract

IT is nearly always desirable, when breeding animals like mice for laboratory use, to select for high productivity, that is, for the largest number of healthy offspring per dam in a given time. This is a function of litter size and ‘pre-natal interval’; the time between exposure to the chance of mating and the birth of the first litter, or the time between the births of successive litters. The pre-natal interval is only of interest for monogamous pairs which are never separated.