Basic herd production information, and the effects on production of cottonseed supplementation during the late dry season, were obtained from a herd of Shorthorn cattle under simulated range cattle conditions near Kununurra, Western Australia, over the period September 1967 to April 1970. Mean breeder liveweights fluctuated from a low in the late dry season (late December) to a high in the post wet season (June) by up to 86 kg per head. Calves continued to gain weight throughout the year, with rates of liveweight gain from 0.07 to 0.64 kg per day during the late dry season and wet season respectively. Under the uncontrolled mating conditions of the trial up to 65 per cent of the breeders were in calf between May and September, and as few as 20 per cent were recorded between October and March. Estimated calving percentages varied between 70-80 per cent with an average weaner turnoff of between 62 and 74 per cent. Supplementation with cottonseed arrested late dry season breeder liveweight losses to some extent in two of the three dry seasons. Calves from the supplemented group made higher liveweight gains during the late dry season period of supplementation than unsupplemented calves. The total number of calves weaned per 100 breeders during the trial was 177 for the supplemented herd and 171 for the nonsupplemented herd, with an average liveweight of 188 and 182 kg respectively. The applicability of these results to the surrounding pastoral areas is discussed.

Full text doi:10.1071/EA9710508

© CSIRO 1971