No significant effect of maternal perception of the food environment on reproductive success or pup outcomes in C57BL/6J mice

OBJECTIVE: Prior work concerning maternal perception of the food environment suggests that perceived disparities in food resources resulted in reduced pup mass and dam reproductive success. We attempted to replicate this result with increased sample size and additional measures. METHODS: Female C57BL/6J mice (n=160; 3 weeks old) were randomized to either subject or peer and were pair-housed in partitioned cages with olfactory and visual contact. After a 6-week maturation period on an energy-rich cafeteria diet, cages were randomized to Control (subject and peer fed pelleted diet) or Treatment (subject fed pellets, peer fed cafeteria diet), and subjects were bred. After weaning, one pup from each sex per litter was reared to five months. RESULTS: Treatment did not affect the number of births, pup size at birth or proportion of pups surviving to weaning (p>0.09). Treatment did not affect dam body or fat mass at parturition (p>0.22) but these measures were higher in some Treatment dams at weaning (p<0.05). Smaller female pups were weaned from Treatment dams pregnant on the first breeding attempt (p=0.01), but no other pup effects were observed (p>0.07). CONCLUSIONS: Exposure to food-environment disparity in this study did not replicate previous findings or affect pup growth after weaning.