ABSTRACT
The success of intensive systems of dairy and beef production used throughout North America depends, in part, on the use of highly productive cattle that are raised under conditions in which the environmental variables that affect production have been controlled or extensively modified. In the dry tropics, the pasture growing season is short and cattle have to cope with extreme fluctuations in both quality and quantity of feed. Periodic droughts are also a feature of the dry tropics. Studies at the Tropical Cattle Research centre and its nearby field station "Belmont," Rockhampton, Queensland, have been aimed at identifying attributes required for efficient production in the tropics of northern Australia. Under extensive pastoral systems of management, there is little or no scope for modification of the climatic variables, and the alleviation of any effects on production must then be by genetic means.
