THE NUTRITIONAL CONTROL OF THE GROWTH AND PROPERTIES OF MOHAIR AND WOOL FIBERS - A COMPARATIVE REVIEW

The effect of nutrient status on the growth and properties of wool and mohair fibers is reviewed: the aim is to compare effects on sheep and Angora goats and emphasize differences between the species. Wool grow th is markedly influenced by nutrition; the requirement for energy-yie lding nutrients is low and the major nutrients limiting wool growth ar e essential AA, sulfur-containing AA being especially important. An ad equate supply of Cu, Zn, folic acid, and pyridoxine is required to mai ntain wool growth. Both length growth (L) and diameter (D) of wool fib ers respond to changes in nutrient supply such that the ratio of L:D r emains approximately constant. Mohair production is influenced by nutr ient supply. However, the importance of specific nutrients has not bee n established, apart from one study showing that mohair growth respond ed to parenteral supplementation with methionine. In contrast to sheep , some studies indicate that length growth of mohair fibers may not be very responsive to changes in nutrient status. The responsiveness of mohair growth (both length and diameter) to nutrient supply at differe nt times of the year has not been reported. The energy requirement for fiber growth may be greater in goats than in sheep, but more studies are needed.