APPLICATION OF STANDARDIZED, ACCUMULATED TRANSFORMED EARNINGS IN BREEDING OF NORWEGIAN TROTTERS

Earnings of horses were accumulated over age-class(es), and unraced ho rses were assigned zero earnings. The variables were power transformed (0.20) and standard normalized within birth year. Four resulting accu mulated transformed and standardized earnings (ATSE) variables, for 18 90 offspring by 74 base population sires, were analysed. A multivariat e sire model was used in an initial analysis aimed at estimating pheno typic parameters, while a corresponding mate-corrected sire model was applied to estimate genetic parameters. Breeding values of mates were predicted by a multivariate animal model using data of all animals (14 054) and parameter estimates from the initial analysis. The heritabili ty estimates of ATSE variables over age-classes 3, 3-4, 3-5 and 3-6 ye ar increased with increasing percent of raced horses and were 0.14, 0. 20, 0.23 and 0.22, respectively. Phenotypic correlations were all grea ter than 0.70, and the genetic correlations approached 1.00. Sex and b irth year effects were included in all analyses and in the proposed 4- trait animal model evaluation routine. Young sires should be selected on ATSE3-4 breeding values which showed a significant genetic trend of 3.2% of a phenotypic standard deviation per year.