Increase of litters in holtzman rats in a university bioterium

Abstract

The present research work was carried out in the biotherium of the Facultad de Farmacia y Bioquímica de la Universidad Nacional de Trujillo between June 2017 and August 2018, with the objective of characterizing the reproductive parameters in Holtzman rats such as their reproductivity, fertility, gestation completion, breeding abilities and others. Initially we worked with 78 females, later with 48 and in addition to this a polygamous and a monogamous group, each with four females and one male. Pregnancy was identified by observation of the lateral growth of the abdomen. Feeding consisted of 25 g of barley, corn, balanced poultry feed per animal per day and water. The biosecurity protocols of the biotherium were complied with. Treatment 1, in groups of 4 females and one male (polygamic reproduction), 117 broods were born and 110 at weaning, litter size at birth (TCN) 4, litter size at weaning (TCD) 3.8 and 94.02% survival rate. Treatment 2, in groups of four females and one male, 193 pups were born and 182 pups at weaning, TCN 6.7, TCD 6.3, 94.3% survival, an average individual weight of 23.05 ± 1 and 145 g per litter. In treatment 1, a litter of 13 (100% survival), TCD 13, 371 g litter weight and an average individual weight of 28.75 ± 1.46 g was achieved. In treatment 2, a TCN 13 (100% survival), TCD 13 with a litter weight of 385 g at weaning and an average individual weight 29.5 ± 0.34 g was obtained. Reproductive management of a monogamous mating system with high resting increases litter size/reproduction and litter weight at weaning.