[Sow herd replacement and selection of young sows for breeding]
2001
Cerovsky, J. | Hudecek, V. | Rozkot, M. (Vyzkumny Ustav Zivocisne Vyroby, Kostelec nad Orlici (Czech Republic))
The aim of the study was to evaluate reproductive performances of sows, to establish phenotypical correlations between reproductive performances, growth and slaughter values. The first oestrus occurs between 141 and 240 days of age, differences were observed between the breeds studied (Large White, Landrace and Large White x Landrace). Between 10 and 40 % of animals are culled because of the absence of oestrous cycle. Weight gains and backfat thickness both have positive effect on the age at the first insemination. Surprisingly, weight gains have negative effect on the age at first farrowing, while backfat thickness have positive effect on this parameter. The culling rate should be between 30 and 40 %.
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