engleski

Partition of genetic trends by origin in Landrace and Large White pigs

Import of genetic material from other populations into national pig breeding programmes might have positive or negative impact on selection results. The objective of this study was to partition genetic trends for backfat thickness and time on test by origin in pig population in conventional pig breeding programme based on selection of pure breeds. Breeding values were estimated on 25, 553 Landrace and 10, 432 Large White pigs on four large scale farms and on the group of 72 family farms. Available information from pedigree about origin was whether animal was registered within analysed breeding programme or was imported into breeding programme. Linear models with genetic groups and without genetic groups were applied. In total, three genetic groups were defined for Landrace and two for Large White pigs. Correlations between breeding values were estimated by two types of models. Based on the results of comparison of models, model with genetic groups was chosen for estimation of breeding values. Genetic trends were partitioned by origin for backfat thickness and time on test. At the end of analysed period for backfat thickness, the relative effect of animals of imported origin was 0.78% and 0.63% for Landrace and Large White, respectively. The relative effect of animals of imported origin for time on test was 0.78% for Landrace and 0.61% for Large White pigs.

pigs; backfat; time on test; genetic trend; origin

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