GENETIC AND PHENOTYPIC INVESTIGATION OF PERFORMANCE-CHARACTER, SEMEN-CHARACTER AND FERTILITY-CHARACTER OF ARTIFICIAL-INSEMINATION BOARS .1.SYSTEMATIC EFFECTS AND GENETIC-PARAMETERS

With data of the German Hybrid programme several systematic effects up on semen and fertility characters of AI boars can be estimated. Among others boar line (litter type), AI station, season and boar age affect systematically traits of boar ejaculates. Besides systematic effects of litter type, litter number, form and season increasing age of the e jaculate negatively affects the fertilization rate and litter size. He ritabilities for semen quantity and quality traits are of medium size and allow genetic improvement by selection. In the analysis of fertili ty traits boars are considered as animal and sows as random effects in the animal model. As expected very low heritabilities and repeatabili ties for fertilization and litter size traits were found. Selection am ong boars for these traits will therefore yield low effects.