Dataset. Proper micro-environment alleviates mortality in laboratory mouse breeding induced by litter overlap and older dams.

Le résumé fourni par la source

The ongoing worldwide effort to reduce animal numbers in research often omits the issue of pre-weaning mortality in mouse breeding. A conservative estimate of 20% mortality would mean approximately 1.1M mice die annually in the EU before scientific use. We hypothesized that pre-weaning mortality in laboratory mouse breeding is associated with cage social and macro/micro-environment conditions. Here we counted pups from 509 C57BL/6J litters daily for accurate detection of mortality, and monitored cage micro-environment for 172 C57BL/6J litters. Probability of pups to die increased with the increase in dam age, number and age of older pups in the cage (of overlapped/cohabitating litters), and in small (<6 pups) and large (>11 pups) focal litters. Higher temperatures (>23.6°C) and nest scores (>3.75) compensated for some of the socially-associated risks for pup death. These findings can be implemented in strategies for reducing pre-weaning mouse mortality, a more welfare-friendly and sustainable approach for science.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.