Increased maternal non-esterified fatty acid concentrations during late gestation impair adipose tissue development and metabolic function in Holstein offspring calves

Lay Summary During late gestation, some dairy cows have greater circulating concentrations of non-esterified fatty acids (NEFA), which are fats released into the blood when energy is limited. In this study, we examined whether this condition affects fat tissue development and metabolic health in newborn calves. We compared calves born to cows with lesser or greater blood NEFA concentrations and evaluated fat tissue growth and function at birth and one month of age. Calves from cows with greater NEFA concentrations exhibited abnormal fat development soon after birth, including reduced fat stores, a decreased ability to produce heat, and increased signs of inflammation. As these calves grew older, they developed increased fat accumulation, poorer control of blood glucose, and ongoing metabolic problems. Additional experiments using calf fat cells grown in the laboratory showed that greater NEFA exposure directly interfered with normal fat cell development and increased inflammation. Overall, our findings highlight the importance of good energy and nutritional management of cows during late pregnancy to support healthy development in their calves.