[Postnatal loss and the possible effect of overcrowding in a high fertility mouse population].

Abstract

Mice characterized by a mean litter size of 17 pups in the first litter were held in cages of different size. No overcrowding effect on preweaning growth and survival rate have been found when the population was held in type I cages (195 cm2 bottom area) as compared with keeping in type II cages (416 cm2). The increased mortality during suckling is due to an insufficient lactation performance of the mothers.