Genetic parameters for conformation traits in dairy goats
Improving the functional fitness of dairy goats for traits such as animal mobility and structural correctness is important for ensuring continued animal health if genetic selection for increased productivity is actively pursued. The aim of this work is to quantify genetic and phenotypic properties of udder, teat, legs and feet scores together with milk yield in UK dairy goats. The data set comprised 2,429 conformation records (udder, legs, and feet) and 126,262 milk yield records on 2,429 first lactation mixed breed dairy goats, scored for conformation in 2013. The pedigree file contained 30,139 individuals. In total 10 conformation traits were scored on a linear scale (1-9) by one scorer from captured photographic images. Covariance components were estimated with the AI-REML algorithm in the DMU package with an animal model containing farm, lactation stage, and birth year as fixed effects. Heritability estimates for conformation traits, ranged from 0.02 to 0.45. Significant genetic correlations were detected between udder furrow and udder depth (0.74), udder attachment (0.66), teat shape (0.96), and back legs (0.57). Teat angle was correlated with teat placement (0.60), back legs (0.48), and back feet (0.67). The phenotypic correlations ranged from 0 to 0.39. Genetic correlations estimated between milk yield and udder and teat conformation traits were negative, ranging from -0.60 to -0.20, and from -0.50 to -0.20, respectively. Genetic correlations with feet and leg conformation were between -0.30 and 0.30. Udder and teat conformation traits were low to moderately heritable and feet and legs traits less heritable. The genetic correlations between the conformation traits and milk yield indicate that breeding programmes for dairy goats should include conformation scores, so that selection for productivity is not accompanied by deterioration in functional fitness especially in udder, teat and leg conformation.
Other Titles/Title of Conference
66th Annual Meeting of the European Federation of Animal Science, Warsaw, Poland