Basic biological data on growth, reproduction and mortality for beef herds in Queensland, Northern Territory and the northern part of Western Australia have been collated and summarised. The objectives were to identify gaps in knowledge as a basis for future research planning and to provide reliable input data for herd dynamics and simulation models. The data were available as a by-product of research projects conducted to satisfy other objectives. Data for breeders and growing animals were considered separately and north Australia was divided into 16 regions based on native pasture communities and statistical divisions. A hierarchy was used to summarise and indicate the importance of data at different levels of specificity. Firstly, a bibliography of research reports containing production data was compiled. Secondly, indices were established to rank the data sets on their quality and quantity. Thirdly, the key management practices were described and production traits for fertility, liveweight, growth and mortality were summarised by giving their range over the years recorded.
Production data from 76 research reports and 146 sites for breeders and from 139 research reports and 237 sites for growing animals were summarised. Northern and southern spear grass regions in Queensland and Darwin/Gulf region in Northern Territory had the most production .data for breeders. On the other hand there was virtually no relevant information on breeders for mulga, mitchell grass downs and peninsula regions of Queensland, Alice Springs region of Northern Territory and Pilbara region, of Western Australia. Fertility data were quoted in virtually all studies (142/146), but mortality (29/146) and liveweight (56/146) were quoted much less frequently. For growing animals there were adequate production data for the high rainfall, northern and southern spear grass and brigalow regions in Queensland and Darwin/Gulf region in Northern Territory. Other regions, particularly mulga, spinifex, gulf lowlands and peninsula in Queensland, Barkly Tableland in Northern Territory and Pilbara in Western Australia, were poorly represented by relevant research reports for growing animals. Most growth studies (194/237) reported either annual average daily gain or weight at the end of 12 months grazing, while mortality rates were rarely given (7/237).
Priorities for future collection of basic biological data in different regions of north Australia were determined by assessing the quality and quantity of research information which was already available, the number of cattle in each region and the advice of scientists, advisers and producers from the Review Workshop in Townsville in November 1987. There was a clear need for more information on mortality rates in all regions given the impact that mortality has on profitability. Apart from this, current data, existing research and opportunistic producer demonstration sites provide adequate basic biological data without the need to establish new projects specifically for this purpose. The most important regions with a continuing need for a sound biological database were northern and southern spear grass, aristida/bothriochloa and gulf lowlands in Queensland. Regions with lower but still important requirements for basic data were brigalow in Queensland, Victoria River in Northern Territory and Kimberley in Western Australia.