Relation between insect bite hypersensitivity and body condition score in Dutch Shetland mares

Genetic parameters of insect bite hypersensitivity (IBH) and body condition score (BCS) including correlations were estimated in Dutch Shetland mares using a bivariate sire model. Data consisted of 7,608 mares with 10,735 observations on IBH and 2,809 observations on BCS scored by 19 inspectors during foal inspections at home. Heritability and repeatability of IBH ere 0.05±0.02 and 0.38±0.02 respectively, heritability of BCS was 0.38±0.23, phenotypic and genetic correlation between IBH and BCS were 0.03±0.01 and 0.39±0.37 respectively. The positive genetic correlation between IBH and BCS indicates that both conditions seem to be influenced by common genes in the same direction, although most likely additional genes affect both conditions independently. A higher genetic predisposition for IBH is associated with a higher genetic predisposition for overweight.