Preliminary genetic parameters for flystrike and its association with production traits in Australian Merino sheep

Abstract

<p>This study explored the phenotypic and genetic variation in breech flystrike and its relationship with production traits in the Connemara Merino ram breeding flock. Yearling breech strike (struck/non-struck) had a low heritability of 0.09±0.04 when using a binomial model. Heritability estimates for production traits ranged from 0.12±0.04 (for faecal worm egg count) to 0.70±0.07 (for staple length). Genetic correlations between breech strike and production traits varied from negative (-0.25±0.24 for fibre diameter) to high positive (0.70±0.21 for dag score), illustrating both favourable and unfavourable relationships that will have implications for future selection programs incorporating breech strike resistance with production traits. </p>