Effect of crossbreeding on components of Hogget wool production

Abstract

Australia's prime lamb industry is based on systematic three way crossbreeding. This paper examines various genetic effects on wool production, important determinants of profitability of the meat-sheep enterprise. Data from three purebred (Merino, Corriedale and Dorset Horn), six F1 and the six three-way cross lines were analysed. Direct genetic effects were important for all traits analysed. Maternal effects were generally not important. Individual heterosis was large for clean fleece weight (13%) and hogget weight (10%) and important also for fibre diameter (2%). Maternal heterosis averaged 3% for clean fleece weight, -2% for fibre diameter, and 1% for hogget weight (5% rams; -3% ewes). These results support the hypothesis that the action of individual heterosis through increased nutrient demand results in increased mature weights. Also, the effect of maternal heterosis is to increase nutrient supply resulting in increased rates of maturation.