Effects of genotype and environment on wool production of Merinos at pasture at two locations in semi-arid tropical Queensland

Abstract

The problem of low wool production in central- western and north- western Queensland led to a study of the relative wool production of different genotypes of Merino sheep in these 2 regions. A number of the bloodlines of sheep introduced to central western and north-western Queensland attained a higher mature liveweight (P<0.01) and produced more wool (P<0.05) than the locally bred sheep. Annual wool production was closely related to mature liveweight, and the strong wool South Australian Merinos were consistently the heaviest and produced the most wool. Ranking on fleece characteristics and liveweight was consistent for both locations. Under severe nutritional stress, the sheep introduced to north-western Queensland showed a significantly (P<0.05) greater drop in tensile strength of their wool than locally bred sheep. There was a significant difference (P<0.05) between productivity levels of the sheep at each location, with the environment in central-western Queensland being more suited to wool production. The results of this experiment suggest that some bloodlines of Merinos offer the potential to improve the wool production of sheep bred in central- western and northwestern Queensland; however, the effect of rearing environment may also be important.