Variation in the Sulphur Content of Wool of Merino Sheep Associated with Genetic Differences in Wool-Producing Capacity

Abstract

The sulphur content of wool may be influenced by a number of factors. Copper deficiency has been shown to reduce sulphur content (Marston 1946), while the administration of sulphur-containing amino acids or casein directly into the abomasum has been shown to increase substantially both the sulphur content of wool and the rate of wool growth (Reis and Schinckel1961, 1963, 1964). Variation in the nutritional status of both pen-fed (Reis 1965) and grazing (Reis and Williams 1965) sheep, associated with variation in either the amount or the composition of the diet, has also been shown to influence sulphur content; wool growth and sulphur content have both increased as nutrition has been improved, and vice versa. Variation in the sulphur content of wool from grazing sheep has also been reported by Ross (1961, 1964) who suggested that there was an inverse relationship between rate of wool growth and its sulphur content. The sheep observed by Ross were Romney ewes and Reis and Williams (1965) have cast some doubt on the relationship suggested by Ross on the grounds that the seasonal variation in wool growth may have been affected by factors other than nutrition.