Wheat gluten during pregnancy and lactation: effects on mammary gland development and pup viability

Diets containing 13% protein supplied by wheat gluten (WG), wheat gluten + lysine + threonine (WGLT), or casein + methionine (CM) were fed to pregnant rats from conception through day 15 of lactation. A crossover design was used with combinations of WG, WGLT, and CM during pregnancy and lactation. Out of six dams fed WG during both pregnancy and lactation and nursing a total of 48 pups on day 1 of lactation, only two pups were still alive on day 15 of lactation. In contrast, CM dams still were nursing 47 pups at this time. Differences in the weight and composition of mammary tissue were directionally similar to and consistent with pup viability. The data obtained confirm the importance of protein quality in the lactation diet and also demonstrate that deficits in mammary gland development occurring during pregnancy may not necessarily be overcome by a nutritionally adequate diet consumed during lactation.