THE function nutrients play with wool follicle and its link to wool quality could hold the key to greater wool production. Nutrition and its effect on wool quality was the subject of CSIRO senior principal research scientist David Masters at this month's National Nutrition Conference, held in Fremantle recently. Fibre diameter and length are two of the main contributors to wool quality as well as staple length, yield and colour, due to influencing wool's processing efficiency, fabric comfort and garment value. Mr Masters told those at the conference how the traditional understanding was that, by changing either fibre diameter or length, the other characteristics would be adversely affected. But increasing the staple length of wool without increasing micron measurements could soon be possible by using nutritional manipulation. "Targeted manipulation of key metabolic processes or of the relative synthesis of the root sheaths and fibre might achieve desirable changes in fibre length and diameter in the future," he said At present staple length, diameter and strength were being manipulated through breeding, and pasture and grazing management. The key nutrients currently being looked at in testing were cysteine, which was needed for keratin synthesis, as well as lysine and methionine, both of which were found in higher concentration in the follicle's inner root sheath. "Nutrition influences the length and diameter of wool and the relationship between the two through cell division and protein synthesis in the follicle," he said. He said that nutrient intake also contributes to strength through effects on fibre diameter variability and possible keratin composition. "While nutritional effects on fibre growth and properties have been reported and described, the full functional roles of most nutrients used for wool are poorly understood," he said. Mr Masters added that research into supplying wool fibres with these targeted nutrients would probably not give the industry a short-term boost, and that wool prices would have to increase for it to be justified. But he said research into specific nutrient supplements for wool growth manipulation was next, with other nutritional possibilities including zinc, vitamin B12 and B6, folic acid, and selenium. With nutrients affecting length or diameter growth differently, he said there was also opportunities for plant breeding and selective supplementation.