The effect of United States versus New Zealand Angus germplasm on characteristics of crossbred calves.

Blood selenium concentration at birth and growth from birth through finishing were analyzed on progeny from two birth years of Angus bulls of United States (US) or New Zealand (NZ) origin. Dams of the calves were Polled Hereford x Angus crossbreds whose sires had been selected divergently from the national sire summary to be superior (+) or inferior (-) for yearling weight EPD (G) and for total maternal effects (M) on weaning weight. There was no evidence of differences attributable to calf paternity or dam genetic group in concentration of blood selenium in calves at birth. For birth year 1988, progeny of US sires grew nonsignificantly more rapidly than progeny of NZ sires in most life-cycle phases. In 1989 calves, NZ-sired offspring grew nonsignificantly more rapidly than US-sired offspring through a year of age. Averaged across years, preweaning and postweaning growth rates were similar for calves of US and NZ paternity. Divergent selection of the calves' maternal grandsires for yearling weight EPD was successful; calves in +G groups had more rapid gains through 1 yr of age than did calves in -G groups. Also, growth rate through 4.5 mo of age was influenced by divergent selection of maternal grandsires on total maternal weaning weight EPD; calves from +M groups gained more rapidly than calves from -M groups.