A comparison of spring and autumn calving for beef cattle production

Production from Angus and Friesian beef cattle calving in spring or autumn was measured over 4 years. Patterns of liveweight change were similar throughout the year, but liveweight change was very different in relation to calving and mating. In the spring herd the post-partum anoestrous intervals were long, the calving pattern was poor, and levels of barrennes and calf mortality were high, although calves grew relatively fast. In contrast in the autumn herd, the post-partum intervals were short and the calving was concentrated. However, barrenness was high particularly in some years and there was evidence that cows became anoestrous during winter. Calf mortality was low, but calf growth rates were reduced. The rest&s suggest that neither calving time was optimal in this environment for maximum productivity.