Genetic and phenotypic parameters for wool characteristics in fine-wool Merino, Corriedale, and Polwarth sheep. I. Influence of various factors on production

Estimates are given of the change in the level of production of 10 fleece characteristics of four Merino, one Polwarth, and three Corriedale flocks, in Victoria associated with variation in property, breed, season, property x season, age, and reproductive status. There was a decrease with age of characteristics associated with wool weight, and a decline in general wool quality. The decline was approximately linear for most characteristics from ewes of 3 years of age. Lactation was generally more severe than pregnancy in reducing wool production. The estimates of the effect of age on wool characteristics are used to assess the likely quantity and quality of wool produced by flocks of different age structures. These estimates may be used in conjunction with reproductive performance data to plan for maximum wool production.