The association between non-fleece pigmentation and fleece pigmentation in Corriedale sheep

Abstract

ABSTRACTThe phenotypie associations between scores for various types of non-fleece pigmentation and concentration isolated pigmented wool fibres in the fleece (experiment 1 and 2) or the piebald phenotype (experiment 3) were studied in Corriedale hogget ewes. These sheep were selected on the basis of either degree of nose skin pigmentation (experiment 1), presence or absence of pigmented fibres at the horn sites (experiment 2) and presence or absence of the piebald phenotype (experiment 3). Among affected fleeces the concentration of isolated pigmented fibres (PFC) had high correlations (0·96 and 0·97) with the proportion of staples affected, which indicates that when PFC is high the isolated pigmented fibres are widely distributed throughout the fleece. Three types of non-fleece pigmentation had significant (P < 0·05) positive correlations with PFC in experiments 1 and 2. These were pigmented skin on the nose lips (0·23 and 0·18; P < 0·05), pigmented fibres at the horn sites (0·34 and 0·30; P < 0·01) and pigmented fibres on the legs (0·36 and 0·29; P < 001). The pigmentation of skin or fibres in non-fleece areas was predominantly black/grey and there were usually significant (P < 0·05) positive correlations between the various types of non-fleece pigmentation. In experiment 3, piebald sheep were found to have higher scores for black/grey fibres on the ears (P < 0·001), face (P < 0·01) and horn sites (P < 0·05) and for black/grey skin under the tail (P < 0·01) than non-piebald sheep.