Genetic and Phenotypic Relationships between Kid Survival and Birth Weight in Australian Meat Goats

Abstract

The Australian goat industry would like to improve reproductive rate by increasing kid survival. Parameter estimates for kid survival and correlated traits are yet to be reported. A preliminary analysis of birth weight and survival was conducted using 16,050 records from industry herds. The heritability for birth weight (0.32±0.029) was similar to previous reports, but the heritability for kid survival (0.29±0.024) was higher than expected in comparison to other breeds of goats and sheep. The phenotypic variance for birth weight is similar to those previously reported for Boer goats. For a binomial trait there was moderate variation in kid survival with a phenotypic deviation of 0.288, birth weight had a moderate amount of variation with a standard deviation of 0.599kg. The lowest kid survival rates occur in animals less than 2.5kg with survival rates between 67% and 85%, while animals over 2.5kg had survival rates between 92% and 98%, the overall mean for survival was 85%. The phenotypic correlation estimate of 0.16 is low but positive for birth weight and survival. The genetic correlation was also positive and high at 0.54±0.068. Improving survival could potentially be achieved either with direct selection or indirect selection with birth weight.