Two traits model for litter size over parities in pigs | Dvolastnostni model za velikost gnezda po zaporednih prasitvah pri prašičih

English. The aim of the study was to estimate genetic correlations between litter size in gilts and sows for number of born and number of liveborn piglets. Total 24 334 litters of Swedish Landrace (SL), Large White (LW), and both F1 sows; line 12 (SL × LW) and line 21 (LW × SL) were included. High genetic correlations for number of born piglets (0.92) and also for number of liveborn piglets (0.92) were obtained by animal model. Due to high genetic correlations litter size across litters from 1st to 6th parity can be treated as the same trait. The estimates of heritability for litter size in gilts and sows were higher for number of born (0.14) than for number of liveborn piglets (0.12). The results confirmed the adequacy of a simple repeatability model in the selection for litter size in the population analyzed.

Slovenian. Namen raziskave je bil izvrednotiti genetske korelacije med velikostjo gnezda pri mladicah in pri starih svinjah. Analizirali smo število rojenih in število živorojenih pujskov od prve do šeste zaporedne prasitve. Skupno je bilo vključenih 24 334 prasitev pri pasmah švedska landrace (SL) in large white (LW), liniji 12 (SL × LW) in liniji 21 (LW × SL). Z modelom živali smo ocenili visoke genetske korelacije med velikostjo gnezda pri mladicah in starih svinjah tako za število rojenih (0,92) kot za število živorojenih pujskov v gnezdu (0,92), kar nam je služilo za obravnavo velikosti gnezda pri različnih zaporednih prasitvah kot ene lastnosti. Oceni heritabilitet za velikost gnezda pri mladicah ter pri starih svinjah sta višji za število rojenih (0,14) kot za število živorojenih pujskov (0,12). Dobljeni rezultati nakazujejo primernost ponovljivostnega modela za selekcijo velikosti gnezda v proučevani populaciji.