The Effects of Maternal Energy Restriction During Mid-Gestation on Growth Performance, Immune Function, and Gene Expression in the Resultant Beef Offspring

Abstract

Fetal or developmental programming evaluates the effects of maternal alterations on the developing fetus and the potential consequences later in life. To understand the effects of mid-gestation energy restriction on beef cows and their calves the objectives of this dissertation were to determine the effects of dietary energy restriction on measurements associated with cow energy status, and the effects on growth performance, the humoral immune response, and subcutaneous adipose tissue gene expression in the resultant beef offspring. Pregnant beef cows were allotted into 2 treatment groups during mid-gestation: 1) fed at maintenance (Positive Energy Status (PES)); or 2) fed just below maintenance (Negative Energy Status (NES)). Cows were evaluated for parameters reflective of cow energy status. Positive energy status cows maintained or gained condition where the NES cows lost condition during the mid-gestation treatment period, indicating the intended treatment was met. Progeny were evaluated for growth performance characteristics from birth through the finishing phase. Birth weight was decreased in NES heifer calves (P0.05). Two genes important in adipose differentiation had a tendency (