A study of wool growth. I. Weight of wool

Abstract

The wool production of a small flock of Romney Sheep has been studied for a few years. When the sheep were 1 month old squares were tattooed on to four regions of each sheep.The weight of wool from, and the area of, these squares has been studied.We find that, under good growing conditions, for the same region, all sheep produce the same weight of wool per sq.cm. of skin per day (denoted by c), which is independent of age, seasons, year of birth of sheep, but varies from region to region, being higher the nearer the region to the mid-dorsal line.When conditions are unfavourable the weight of wool a particular sheep produces from a particular region falls below the c value for the region, approximately, by a factor (1 – B/E), where E is the skin expansion ratio of the particular region and B is a number, the same for all sheep and all regions in one season and is greater the worse the season.I am particularly indebted to Dr Hammond, School of Agriculture, Cambridge, and to Mr W. S. Kelly (Australia) for help and advice, and to the Animal Research Station, Cambridge, for providing the facilities for working with sheep. I wish to express my indebtedness to my colleagues of the Biology Department of this Association who have assisted me in various ways, and to Dr Daniels for help with the statistical treatment of the data, and to Mr R. C. Palmer for criticism and help in preparing the results for publication. My thanks are due to Mr B. H. Wilsdon, Director of Research, for his encouragement, to the International Wool Secretariat for providing the sheep, and to the Council of the Wool Industries Research Association for permission to publish the results.