Studies on the Wool Yield of Sheep : IV On the Relation between the Wool Yield and Face Cover of the Corriedale Ewes

In this study 307 Corriedale ewes in total bred at the Miyazaki, Tokachi, and Takikawa Stock Breeding Farms were used as experimental animals, and the wool yields(raw and clean yield) of one fleece and the wool qualities(stretched length and fineness of wool) of one sample taken from the mid-side region were estimated per animal per year(from spring, 1958 to spring, 1959) and then the face cover of each animal at shearing time in spring, 1959 scored by the classification into five grades of face cover and the relations between scores of face cover and wool yield, and wool qualifies were studied by investigating the phenotypic correlations. The results obtained from this study were as follows: 1)The raw and clean wool yields of whole fleece per animal per year showed a slightly increasing tendency as scores of face cover of the Corriedale ewes at shearing time increased. 2)The phenotypic correlations between scores of face cover at shearing time and live-weight just after shearing of ewes varied with flock and age of ewes, and on the whole those correlations, either positive or negative, were found to be low. 3)The phenotypic correlations between scores of face cover and stretched length, and fineness of wool also varied with flock and age of ewes and those correlations were generally found to be very low.