Inheritance of Flystrike Recorded in a Non-Seasonal Rainfall Environment

Abstract

Flystrike records from the Sheep CRC Information Nucleus Flock (IN) were evaluated to assess the influence of sex, birth and rearing type, dam age and sire and dam breed on yearling breech and non-breech strike. Heritability of breech and non-breech strike was estimated under a range of different models, on data comprising records from progeny of three genotypes, namely Merino, Maternal-Merino and Terminal cross, run in a variable non-seasonal rainfall environment. Observed heritability estimates ranged from 0.30 ± 0.10 to 0.43 ± 0.13 for breech strike and 0.16 ± 0.06 to 0.32 ± 0.16 for non-breech strike across genotypes and models. Heritability estimates for both traits on the underlying scale were all high (>0.6), with large standard errors. Flystrike was found to have a similar heritability to estimates obtained in other environments. The identification of key indicator traits for non-seasonal rainfall environments is warranted.