IMPLICATIONS OF THE TIMING OF THE BREAK IN THE SEASON ON THE MANAGEMENT OF HEIFERS IN THE DOUGLAS DALY REGION OF THE NORTHERN TERRITORY

摘要

Cattle growth rates in the Douglas Daly region are typically higher than many other regions of the Northern Territory (NT) due to reliable rainfall (average 1208 mm annually) and the introduction of improved pastures. This, combined with the smaller size of properties (and hence better stock control), means that the controlled mating of heifers for the first time as yearlings is a management option that is considered there. Like most of the NT, the Douglas Daly region has a pronounced wet and dry season, and the timing of the break in the season (the start of the wet season) is probably the most important factor determining heifer growth. This has a large effect on heifer fertility since it is generally accepted that weight is the major factor influencing the onset of puberty and conception (Entwistle 1983).