Lay Summary Maternal nutrition during gestation, especially during key periods of fetal growth and development, is vital for producing a calf capable of meeting its genetic potential. Reduced growth efficiency in offspring is detrimental to producer profitability because maternal nutrient repartitioning prioritizes development of central nervous system over skeletal, muscular, and immune systems. Previous studies have investigated the use of melatonin supplementation to mitigate the effects of nutrient restriction during gestation. Melatonin increased fetal birth weights as well as negating cellular stress prior to birth. The present study investigated the effect of maternal nutrition and dietary melatonin supplementation on fatty acid concentrations and placental fatty acid transporters. Nutrient restriction increased maternal fatty acid concentrations, while melatonin did not influence maternal levels. Melatonin altered gene expression of nutrient transporters in the placenta leading to several nutrient restriction by melatonin interactions for fetal concentrations of fatty acids. In general, fetal fatty acids were altered in nutrient restricted animals supplemented with dietary melatonin. Furthermore, amnionic fluid experienced a depression in branch chain fatty acids when dams were nutrient restricted which was not rescued by melatonin supplementation.
Kennedy et al. (Mon,) studied this question.