Estimation of genetic parameters and genomic breeding values for AI success in French dairy goats

Une étude du caractère de fertilité femelle en espèce caprine a été conduite dans le cadre de l'action innovante CAPFERT soutenue par FGE. Le modèle d'évaluation retenu, les paramètres génétiques, l'évolution du niveau génétique de la population sont ici présentés. L'intégration de ce nouveau caractère en sélection génomique est envisagé en races Alpine et Saanen.

Genetic parameters for artificial insemination (IA) success in French dairy goats were estimated. Data analysis, on a total of 378 269 and 574 477 AI records for Saanen and Alpine breed, respectively, collected from 1981 to 2017, was conducted separately on each breed. The heritability of IA success was estimated using a linear simple repeatability animal model. The model included fixed effects of flock within the year of IA, year within the inseminator, year within the treatment for induction and synchronization of oestrus, year within the lactation order, year within the interval between previous kidding and IA, year within month of IA within region and year within day of IA within region. Random effects were animal, permanent environmental effect and random residual error. Heritability estimates for IA success were 0.052 (0.003) and 0.045 (0.002) for Saanen and Alpine breed respectively. Despite the low heritability, genetic standard deviations were 9 AI points in Alpine breed and 11 AI point in Saanen breed. A significant progress is feasible if a selection is set up on this trait. 831 Saanen and 1075 Alpine bucks were genotyped with the Illumina goat SNP50 BeadChip and genomic breeding values were estimated for IA success trait with a within-breed GBLUP (genomic best linear unbiased prediction) model. A low negative correlation (-0.12) between milk yield index and IA success index in Saanen breed, and low positive correlations between fat (0.16) or protein (0.13) index and IA success index in Alpine breed were estimated. In 2020, a genomic evaluation for IA success was developed, this trait will be taken into account to produce elite bucks, by considering the index levels of their sires and dams in mating programs. Early genomic indexes will be produced for young bucks so that they can be selected on this trait before entering in the semen production centre.

Marjorie Chassier (Institut de l'Elevage), Agnès Piacère (Institut de l'Elevage), Virginie Clément (Institut de l'Elevage)