Water Penetration into the Fleece of Merino Sheep Affected with Fleece Rot

Fleece rot was induced in 15 young Merino ewes by treatment with repeated application of simulated rain. Forty days after induction, treated and five control ewes were subjected to 50 mm of simulated rain which contained a water soluble dye. Treated ewes absorbed significantly more water than controls (2.3 kg to 1.5 kg). Wool samples were collected at ten cm intervals along the dorsal midline to determine dye concentration and fleece rot development. Dye concentration was significantly higher in the treated than controls at all sites. Dye containing water entered the fleece principally along the dorsal midline, following the skin surface laterally around the body. The fleece rot band contained a high dye concentration. Wool grown after the initial wetting treatment contained less dye than previously leached wool. Wetting treatment changed fleece structure with many cross fibres.