The impact of dietary protein on reproductive performance in rodents (Rats and mice)

Maternal adaptation to pregnancy begins with the periconceptional period including ovulation, fertilization, implantation and early embryonic growth, and this stage is sensitive to nutritional perturbations, which consequently impacts on the postnatal adult health. In this study we investigated the effects of feeding a high and low protein diet over an 8 week period on plasma biochemistry and reproductive performance in mice. Adult virgin fertile female (n=60), were randomly distributed equally to three experimental groups, according to their diets, which contained different dietary protein levels; low (8%); high protein (35%) or adequate protein diet (control, 22%) for 6 weeks before mating and until day 10 of pregnancy. Body weights were not different between groups, but the conception rate for the low protein group was significantly lower than either the control or high protein groups. In those animals that did become pregnant embryo numbers were significantly lower in the low protein group compared to the control and high protein groups. Blood urea nitrogen and glucose were significantly lower and cholesterol higher in the low protein group. These results suggest diets low in protein have a significant negative impact on fertility.