Original scientific paper

https://doi.org/10.18047/poljo.21.1.sup.19

THE CONTRIBUTION OF SOCIAL GROUP EFFECT TO VARIATION IN BOARS GROWTH

Tina Flisar ; University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, SI-1230 Domžale, Slovenia
Špela Malovrh ; University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, SI-1230 Domžale, Slovenia
Milena Kovač ; University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, SI-1230 Domžale, Slovenia

Abstract

The aim of the study was to estimate the contribution of group to phenotypic variance of daily gain on different intervals. The focus was on data structure and differences of variance components estimated with and without effect of the social group. Growth of 806 boars from 443 litters was obtained during the field test in nucleus herd of Pietrain breed. A group was defined as pen mates. Most frequently, the group was formed from 6 and 7 boars. Data sets were prepared with SAS Software, variance components were estimated using VCE-6. The results showed the significant contribution of the group to phenotypic variance of daily gain. Inclusion of the effect of social group reflected in lower heritability and the smaller contribution of common litter environment. Further analysis revealed different contributions of components to phenotypic variance of growth rate on different intervals. The proportion of variation caused by common litter environment was larger on the interval from ±32.0 kg to ±48.8 kg of body weight (22%), compared to interval from ±39.6 kg to ±104.1 kg, explaining 1% of phenotypic variation, that could be the consequence of less defined pretest environment. The social group explained 6% of phenotypic variance for daily gain on interval from ±39.6 kg to ±104.1 kg of body weight, however, the contribution was larger on the interval from ±32.0 kg to ±48.8 kg (23%). The results confirmed the group as an environmental component, causing more variation in daily gain shortly after group formation (±32.0 kg), when a hierarchy is established, and later after its set, the contribution decreases

Keywords

pigs; genetic evaluation; daily gain; social interaction; group effect

Hrčak ID:

150629

URI

https://hrcak.srce.hr/150629

Publication date:

2.9.2015.

Visits: 1.228 *