Growth of suckling beef calves in response to parenteral administration of selenium and the effect of dietary protein provided to their dams

Three groups of newborn Hereford-Angus crossbred beef calves were used to study whether parenteral administration of selenium to calves and the amount of forage and protein provided to their dams affects unadjusted body weight, adjusted 205-day body weight, and average daily gain (ADG). 55 calves were given Se (0.05 mg/kg body weight, s.c.) once within 2 days of birth or within 2 days of birth and on days 70, 114, and 149 (47 calves). 49 were untreated controls. Until day 149, cow-calf pairs were pastured in fields in which the amount of available forage was high or low and supplemental protein was or was not provided. Calves were weighed on days 1, 70, 149 and 209. On days 160 and 209, blood was obtained from 33 calves for measurements of Se concentration. Mean consumption of supplemental protein was 0.65 kg/dam daily. Between days 1 and 70, calves that received the first of 4 multiple injections of Se had significantly greater ADG than control calves. Average daily gain for calves given only 1 injection was not significantly different from controls. Between days 70 and 149, ADG of calves increased with dietary supplementation of protein to their dams. It is concluded that strategic administration of Se to calves and dietary supplementation of protein to their dams may result in greater ADG in suckling beef calves during specific time intervals.