Estimates of genetic parameters of trotting performance traits for repeated annual records

Authors

• Jukka Pösö Agricultural Research Centre of Finland, Institute of Animal Production, FIN-31600 Jokioinen, Finland
• Matti Ojala Department of Animal Science, P.O. Box 28, FIN-00014 University of Helsinki, Finland

DOI: https://doi.org/10.23986/afsci.72775

Abstract

The heritability and repeatability of trotting performance traits and genetic and phenotypic correlations among these traits were estimated from repeated annual records of 6934 Finnhorse and 5298 Standardbred trotters. The number of observations in the two breeds was 19 550 and 14 184, respectively. (Co)variance components were obtained with animal model and restricted maximum likelihood (REML) method. The heritability estimates were highest for time traits (0.29 to 0.35) and lowest for number of starts (0.08 to 0.10) in the two breeds. The repeatability estimates were high for time traits but only moderate for other trotting performance traits, suggesting that repeated records improve accuracy in genetic evaluations. The genetic correlations among the performance traits, especially between time and money traits, were very high and favourable considering the breeding goals. The phenotypic associations were distinctly weaker than the genetic ones.