Effects of maternal diet, body weight and body composition on infanticide in Syrian hamsters.

We examined the idea that female hamsters kill and eat their own offspring as part of an organized mechanism that balances litter size with metabolic energy supply. In Experiment 1, females fed diets that made them lighter and leaner cannibalized more offspring and maintained smaller litters than females fed diets that made them heavier and fatter. A greater supply of metabolic energy from the diet and/or from body fat stores may have attenuated cannibalism in heavier mothers. In Experiment 2, food restriction during lactation increased the level of cannibalism to a greater degree in lighter, leaner mothers. Heavier, fatter mothers may have eaten fewer offspring because they were better able to mobilize fatty acids from adipose tissue as an alternative fuel source during food restriction. These results suggest that an important factor influencing cannibalism of pups is the general availability of metabolic fuels from both external (food supply) and internal (adipose tissue) sources.