Fetal Programming and Its Implications for the Beef Industry

摘要

Nutrient deficiency often occurs in animals provided forage-based diets due to seasonal variation in forage quality and quantity. This nutrient deficiency has been shown to impact reproductive performance of cows, but also fetal development. Maximal placental growth, differentiation, and vascularization occur during the early phase of fetal development, whereas muscle and adipose tissue development occurs primarily from mid-gestation to calving. Thus, calf development during gestation is susceptibleto maternal nutrition, which might lead to long-term effects on postnatal growth and reproductive performance of calves. Protein supplementation during the last trimester of gestation improved weaning weight of steers and heifers, post-weaning health ofsteers, carcass quality of steers, and puberty attainment and pregnancy rates of beef heifers compared to offspring born to non-supplemented cows. Hence, closer attention and proper nutrition of the herd need to be enforced to avoid or alleviate the negative impacts of nutrient restriction during gestation on cow and calf performance. Research from University of Florida is currently focusing on the use of year-round supplementation or late-gestation supplementation of energy and protein to modify calf development during gestation and improve postnatal health, growth, and reproductive performance. Both strategies significantly improved growth performance and physiological parameters of pregnant beef cows. Calf performance and health following birth arestill under investigation.