Influence of Maternal Nutrient Intake on Placental Vascular Function in Pregnant Beef Cows
Abstract
Two experiments investigating impacts of maternal nutrition in beef cows were conducted; 1) to test the impact of duration of global nutrient restriction and subsequent realimentation throughout gestation on placentome capillary development; and 2) to test the response of protein supplementation on blood flow to the uterus and mammary gland in late gestation. In experiment one, realimentation following varying periods of nutrient restriction had minor alterations in angiogenic factor mRNA expression of as well as vascularity in the placentome. In experiment two, mammary gland blood flow was not affected, while protein supplementation decreased uterine blood flow. Calf birth weights were not influenced by maternal dietary treatment. Results of these studies are important when considering nutritional management of cows during gestation. Further research is warranted to investigate capillary function to determine how compensation is occurring when vascularity is not being drastically compromised with global maternal dietary restriction. Additionally the mechanism of how DDGS supplementation is decreasing blood flow to the uterus is a question which requires more exploration.