Abstract. Title of the paper: Genetic association for daily gain (lifetime) in an crossbreeding program The aim of this investigation is an analysis of the crossing structure of a three-race crossing program and the genetic relations with respect to the trait average daily gain. For this purpose we examine the genetic relations for their usefulness for a estimation of genetic parameters and breeding values. Finally a parameter estimation is carried out. The data basis consists of 1757 German Large White performances, 34980 Landrace performances and 2775 Pietrain performances in pure breed as well as 92757 performances of the crossings of the mother lines and altogether 13854 Pietrain crossings (1997 PI x DL and 11857 PI x DEDL). The heritabilities for the variable daily gain are in the range from 0.17 to 0.31. The genetic correlations between the mother races and their crossbreedings are around 0.9. Between the pure Pietrain and the Pietrain crossings these values reach only 0.7. Within the two groups of crossings with Pietrains the genetic correlations are almost one. From the genetic point of view it is possible to put together the mother races and their crossings as well as the Pietrain crossings. Thus, for this trait it is sufficient to consider a three variable model with separate investigation of the mother races, the Pietrains and the Pietrain crossings.
Estimation of Genetic Parameters and Trends for Weaning-to-first Service Interval and Litter Traits in a Commercial Landrace-Large White Swine Population in Northern Thailand
