Effects of Parity on Neonatal Beef Calf Serum Metabolites during the First 72 Hours of Age

We have previously reported that neonatal calf metabolic status is impacted by calf age and gestational nutrition. Our current objective was to determine the effect of dam parity on neonatal calf nutrient supply, assessed through circulating metabolites. Neonatal calf blood samples were collected from multiparous (n = 15; parity = 4.2 ± 0.7; prepartum BW = 661 ± 17 kg; BCS = 5.3 ± 0.5; gestation length = 274.8 ± 0.6 d; 9 bull and 6 heifer calves) and primiparous (n = 13; BW = 560 ± 19 kg; BCS = 5.1 ± 0.2; gestation length = 276.6 ± 0.7; 8 bull and 5 heifer calves) dams. Pregnant dams were managed similarly in late gestation, then moved to dry lots (d 266 of gestation) and fed ad libitum tall fescue hay (6.7% CP and 63.9% NDF, DM basis) and 1.0 kg DM/d DDGS. Calf jugular blood samples were obtained at 0 (pre-suckling but after standing), 6, 12, 24, 48, and 72 h postnatally for blood chemistry analysis. Data were analyzed using a mixed model containing effects of parity, sampling hour, and their interaction, and hour was a repeated effect. Parity did not affect (P = 0.33) calf birth weight. A parity x sampling hour interaction (P ≤ 0.02) was detected for serum glucose, blood urea nitrogen (BUN), creatinine, albumin, total protein, and globulin. Calves from primiparous dams had greater (P = 0.03) glucose at 0 h, but calves from multiparous dams had greater (P ≤ 0.04) glucose at 6, 12, 24, and 72 h. Serum BUN tended to be greater (P = 0.09) in calves from primiparous dams at 12 h, but was greater (P = 0.03) in calves from multiparous dams at 72 h. Creatinine tended to be greater (P = 0.06) at 0 h and was greater (P ≤ 0.005) at 12 and 24 h in calves from primiparous dams. Calves from primiparous dams had greater (P ≤ 0.03) albumin at 6 and 12 h. Total protein was greater (P ≤ 0.04) in calves from multiparous dams at 0, 6, and 12 h and tended to be greater (P = 0.07) at 72 h. Globulin was greater (P ≤ 0.003) in calves from multiparous dams at 0, 6, and 12 h and tended to be greater (P = 0.06) at 48 and 72 h. Results indicate parity impacts metabolic status of calves, but likely in a time-dependent manner.