Modification of fleece development in Blackface sheep by variation in pre- and post-natal nutrition

Abstract

1. Wool production and fleece structure were studied by fibre analysis in six groups of lambs subjected to different pre- and post-natal levels of nutrition. Samples were taken at 6, 12, 28 and 48 weeks of age.2. Pre-natal limitation (twin pregnancy) reduced the number of secondary fibres present at birth but, providing post-natal nutrition was adequate, this difference had disappeared by 6 weeks. There were no permanent effects on fibre number, wool production or fleece structure.3. Severe post-natal restriction of feed intake during the first few weeks of life had a marked effect on the development of the secondary fibre population, on wool production and on the birthcoat shedding cycle. The effects persisted beyond the period of nutritional limitation but had disappeared by 12 months of age.4. The results are discussed in relation to the normal development of the adult Blackface fleece.