HERBAGE INTAKE, LIVEWEIGHT GAIN, AND GRAZING BEHAVIOR OF FRIESIAN, PIEDMONTESE X FRIESIAN, AND BELGIAN BLUE X FRIESIAN BULLS

The introduction of heavily muscled breeds of cattle has provided New Zealand farmers with a wider breed choice, but no data on the performance of these breeds, relative to the Friesian for bull beef production on pasture are available. Thirty Friesian, Piedmontese x Friesian, and Belgian Blue x Friesian bulls were purchased at 3 months of age and farmed to slaughter at 18-20 months of age. Herbage intake was recorded over 18 days when the heaviest group of bulls was 15 months old. Herbage intake (kg DOMI/bead per day) was similar for the three breeds under continuous stocking on a ryegrass-white clover sward maintained at a sward surface height of 8-10 cm. The Belgian Blue x Friesian bulls had lower biting rates (P < 0.05) and spent more time idling than the other two genotypes. There was no difference in the rate of liveweight gain over the intake measurement period, or in final liveweight between the genotypes. Bulls of the heavily muscled genotypes both had higher rates of carcass and meat gain (P < 0.05) than the Friesian bulls. Farmers could pay a premium for replacement calves of the heavily muscled genotypes because of their greater dressing-out percentage in comparison to straight-bred Friesians.