PSI-15 Factors affecting circulating metabolites and postnatal growth in spring-born neonatal beef calves

Abstract

Abstract The objective of this experiment was to evaluate relationships of dam parity and calf suckling within 4 h postnatal with neonatal circulating metabolite concentrations, neonatal environment, and postnatal growth. For the experiment, 36 Angus, Hereford, and crossbred dams (age = 4.0 ± 1.74; multiparous (n = 5) and primiparous (n = 31); BCS = 6.5 ± 1.04; average calving date = April 4, 2018) were used. Calves were observed using a digital video recording system for 4 h after birth to determine suckling success [S = suckled (n = 27) or NS = did not suckle (n = 5) ≤ 4 h]. Jugular blood samples were obtained from calves at 24 (24.4 ± 1.73) and 48 to 72 (54.7 ± 9.08) h of age to determine serum blood urea nitrogen (BUN), glucose, non-esterified fatty acids (NEFA), and total protein (TP). Postnatal growth measures were collected at 50.4 ± 13.6 d and 162 ± 19.7 d of age. Calf BW was greater (P ≤ 0.02) at 50 and 162 d of age and ADG (0 to 162 d) was greater (P = 0.04) for S than NS calves, however birth BW was not different (P = 0.69). Ambient temperature at parturition was colder (P = 0.03) for NS calves than S calves. Serum glucose at 24 and 72 h was greater (P ≤ 0.03) in S calves than NS calves, however NEFA, BUN, and TP were not affected (P ≥ 0.09) by suckling success at either sampling time. Dam parity had no effect (P ≥ 0.12) on calf circulating metabolites at 24 and 72 h postnatal. In conclusion, the success of beef calves to suckle within 4 h of birth is associated with greater circulating glucose, warmer ambient temperature at birth, and greater postnatal BW and ADG.