918
Effects of Maternal Plane of Nutrition During Mid- or Late Gestation on Beef Cow Performance and Progeny Performance Through Weaning
Objectives were to investigate the effects of maternal plane of nutrition during mid- or late gestation on cow BW, BCS, and lactation, as well as calf growth through weaning. Spring-calving, multiparous cows (n = 68; BW = 631±80 kg) were utilized in a 3 × 2 factorial design that included 3 planes of nutrition formulated to provide (limit-fed diet = 52% corn silage, 24% soy hulls, and 24% alfalfa haylage): 100% NRC energy and protein requirement (REQ), 70% NRC requirement (70%REQ), or 130% NRC requirement (130%REQ) applied during 2 stages of gestation: mid-gestation (MID, 196±14 to 113±14 d prepartum) or late gestation (LATE, 92±6 to 9±6 d prepartum). After treatment period, cows were fed a common diet formulated to meet NRC requirements. Treatment period ADG and BCS changes were greater (P ≤ 0.01) for cows fed 130%REQ than 70%REQ, with REQ being intermediate. There was an interaction (P = 0.04) between plane of nutrition and stage of gestation in which treatment was applied for calf birth BW. When treatments were applied during mid-gestation, birth BW was greater (P ≤ 0.04) for calves born to cows fed 70%REQ compared to calves from cows fed REQ or 130%REQ; however, there were no differences (P ≥ 0.65) during late gestation. Milk production, at 101±11 d postpartum and weaning (198±11 d postpartum), was not affected (P ≥ 0.19) by plane of nutrition. Calf weaning BW was not affected (P ≥ 0.17) by plane of nutrition or stage of gestation in which treatments were applied. Ultrasound backfat at 101±11 d of age was greater (P ≤ 0.04) for calves born to REQ vs. 70%REQ or 130%REQ cows, yet was not different (P = 0.12) at weaning. Ultrasound marbling score was not affected (P ≥ 0.35) by plane of nutrition, but; was greater (P≤ 0.01) for calves born to MID cows at 101±11 d of age. Placing cows on diverging nutritional planes either during mid- or late gestation had profound effects on cow ADG and BCS change and may lead to altered calf body composition through weaning but did not affect calf weaning weight or pre-weaning ADG. There were no effects of an interaction between maternal plane of nutrition and stage of gestation in which treatments were applied, except for increased birth BW of calves born to cows that were nutrient restricted during mid-gestation.
Keywords:
beef cow gestational nutrition fetal programming