Abstract

ANTONINI, Alicia G.; CORVA, Santiago G.  and  OYARZABAL, María Inés. Selección por tamaño de camada en conejos para carne. BAG, J. basic appl. genet. [online]. 2008, vol.19, n.2, pp.01-07. ISSN 1852-6233.

In rabbits, most of selection programs are mainly focused on prolificacy and indirectly, with low pressure, on fertility, thus rejecting sterile females. The aim of this work was to evaluate selection response to weaning litter size (tcd) on meat rabbits during seven generations and to estimate heritabilities and genetic correlations with total birth litter size (tct) and alive birth litter size (tcv). Records for litter size, fertility and survival (on 390 does with two or more pregnancies mated with 63 males) were analyzed. Selection differentials, selection responses, genetic correlations and heritabilities were calculated. The selection differentials were positive in all the generations, nevertheless, the observed selection responses oscillated between positive and negative values not allowing to establish a tendency in none of the studied characters (regression coefficients of each character on generations: btct=-0.02, btcv=-0.03, btcd=-0.27; p>0.05). Despite the fact that the selection was based on litter size, there were no increases on selected character and its correlated characters (tct and tcv). Natural selection was not the reason of this absence of response. Heritability low values indicated that phenotypic variability is due to non additive effects, environmental effects or their interactions and could explain these results.

Keywords : Selección; Tamaño de camada; Conejos.

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