GENETIC AND PHENOTYPIC RELATIONSHIPS BETWEEN CONFORMATION AND PRODUCTION TRAITS IN AYRSHIRE HEIFERS

First lactation records for production traits (milk, fat and protein y ields) and 17 linear type traits for 7169 Ayrshire heifers were analys ed to estimate genetic parameters for type traits and to examine the r elationship between type and production traits. A multivariate restric ted maximum likelihood procedure fitting a sire model with sire relati onships included was used for all analyses. Heritabilities for product ion traits were approximately 0.3 and genetic correlations among them were high (>0.84). The estimates of heritabilities for type traits wer e mainly low to moderate ranging from 0.04 to 0.42. Angularity (0.80), beef shape (0.49), foot angle (0.53) and stature (0.46) had higher he ritabilities. Generally phenotypic correlations among type traits were lower than the genetic correlations. The highest negative genetic cor relation was between rear legs side and rear legs rear (0-95) and the highest positive correlation between chest width and beef shape (0.93) . Genetic correlations between type and production were low to moderat e and were similar for milk, fat and protein yields. The genetic corre lations between the production traits and chest width, udder depth and beef shape were negative but were positive between production and ang ularity, rear udder width and teat placement side.