OBSERVATIONS ON FIBRE DIAMETER VARIATION OF SHEEP IN RELATION TO FLEECE‐ROT AND BODY STRIKE SUSCEPTIBILITY

Publisher Website
Google Scholar
Abstract
A comparative study of various fleece properties known to influence fleece-rot susceptibility was made in a merino flock consisting of sheep which were either resistant or susceptible to fleece-rot and body strike following heavy rains. The fleece properties measured were fiber diameter, fiber diameter variation, wax content, suint content, wax: stunt ratio, suint pH, insoluble N content, wool color and wettability. Fiber diameter variation, due mainly to the presence of coarse, secondary fibers in the staple, was the only fleece property which differed significantly (P < 0.001) between resistant and susceptible animals. The coefficient of variation of fiber diameter was lowered from a mean value of 22.7 .+-. 0.3% in susceptible sheep to 20.0 .+-. 0.3% in resistant sheep. A causal relationship between high fiber diameter variation and fleece-rot susceptibility is suggested. Sheep with irregular fiber size may retain free moisture in the fleece longer, and thereby become more susceptible to fleece-rot than sheep with uniform fiber diameter, other predisposing factors being equal.