Breech strike can be reduced by increased area of naturally bare skin around the perineum of lambs

Abstract

Three experiments were conducted to test the hypothesis that increased naturally occurring breech bareness would reduce the incidence of breech strike. Breech bareness was scored from 1 where wool was growing around the edges of the anus (and vulva in females) to five where there was an extensive area bare of wool (50 cm2 on a 23 kg lamb). There were very few lambs with a bareness score of 5, so for the purposes of these experiments score 4 and 5 were pooled for analysis. The first experiment showed no significant difference between breech bareness scores, although the trend was similar to subsequent experiments. The second (P<0.05) and third (P<0.10) showed that lambs with breech bareness scores of 4 or greater were much less likely to be flystruck. Females had slightly greater mean breech bareness score than males (2.3 vs 2) but were more susceptible to flystrike (P<0.05) in the first experiment. For management reasons, males and females were run in separate mobs in the second and third experiments. Overall, 22%, 16%, 11%, and 0% of lambs were flystruck when they had breech bareness scores of 1, 2, 3 and 4 or greater respectively. Considering the negligible loss of wool, the labour savings, the reduced suffering due to flystrike and the appeal to modern consumers, the trait seems a worthy selection goal.