Estimation of crossbreeding parameters for litter size in pigs
2001
Logar, B. | Kovac, M. (Ljubljana Univ. (Slovenia). Biotechnical Fac., Zootechnical Dept.)
In the research 46 960 parities of Swedish Landrace (SL), Large White (LW), and both F1 sows, line 12 (SL x LW) and line 21 (LW x SL) were included. With repeatability animal model the number of piglets born (PB) and the number of piglets born alive (PBA) in the first six litters were analyzed. The differences between genotypes were estimated by crossbreeding parameters. Mathernal components were studied: additive maternal and additive grandmaternal effect as well a maternal heterosis, all treated as independent variables. The contribution of additive maternal effect to the breed differences (SL-LW) was larger for PBA (0.36) than for PB (0.09). The estimated deviation of the F1 crossbreeds from the mid parental value (maternal heterosis effect) was 0.69 and 0.72, for PB and PBA, respectively. The additive grandmaternal effect which expresses the differences between crossbreeds (SL x LW-LW x SL) is negligible (0.06 for PB and -0.03 for PBA).
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