Preliminary analysis of sire effects on resistance to gastrointestinal nematode infection in Angora and Cashmere goats

Abstract

Genetic resistance to gastro-intestinal nematode infection (GIN) is being investigated on two properties in northern NSW, Australia. Results from natural infections during the first year of a 5-year investigation are presented. Data consists of faecal egg counts (FEC) after natural infection (predominantly with 'Haemonchus contortus') of 222 and 220 progeny of 6 Angora and 9 Cashmere bucks, respectively. FEC^0.33 measured at 5 (FEC5) but not 3 (FEC3) months of age differed significantly among sires in both breeds. Oral vaccination of kids at 1 and 2 months of age with irradiated L3 larvae of 'Trichostrogylus colubriformis' did not influence FEC3 or FEC5. Heritability estimates for FEC5^0.33 were 0.25 ± 0.21 and 0.23 ± 0.19 for Angora and Cashmere goats respectively. The phenotypic correlation between FEC5 and weight at 5 months was -0.21 (P<0.05) in Angora goats and non-significant in Cashmere goats. These preliminary findings are encouraging and broadly consistent with other studies in sheep and some other breeds of goat.