Efeito do peso ao nascer e do tamanho da leitegada ao nascimento no desempenho de fêmeas puras Landrace até a puberdade / Effectofbirth weightandlitter size of femalepurelandrace ontheir performanceuntil puberty

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2011

RESUMO

The aim of this study was to evaluate the effect of litter size in which gilts were born and of their individual birth weight on mortality and cullingof these gilts until the moment of selection and on occurrence of puberty. The study evaluated 1525 landrace gilts, identified and weighted until 18 hours after birth. The gilts were also weighed on weaning (n=1379), nursery ending (n=1198) and rearing ending (n=940). Three classes of litter size were created: Small (7-11 piglets), Medium (12-13 piglets) and Large (14-19 piglets). Evaluated giltswere also divided into three other classes according to birth weight: Light (530-1200 g), Medium (1205-1600 g) and Heavy (1605-2535 g). The risk of death in maternity was higher (P<0,05) in Lightweight gilts from Medium and Large litters compared to Heavy ones, but not in gilts from Small litters. It was observed an increasing of ADG (Average Daily Gain) and weight (P<0,05), according to the increasing of birth weight, from birth to selection. The risk of death in maternity was also higher or tended to be higher in Lightweight gilts from Medium (P<0,05) and Large (P=0,079) litters compared to those from Small ones. There was no effect of birth weight or litter size on the percentage of dead or culling gilts at nursery and rearing, on the percentage of selected gilts and on the percentage of gilts in anestrous until 30 days after stimulation with a male. The risk of not reaching the selection was higher (P<0,085) in Lightweight gilts than in Heavy ones, in all litter size classes. Lightweight gilts had higher ASM (Age of Stimulus with a Male) and lower MPI (Male-Puberty Interval) compared to Heavy ones (P<0,05), but there was no effect of birth weight on puberty age (P<0,05). The results show that birth weight is more important than the litter size in which the gilt was born in terms of survival until weaning, weight gain and permanence in the herd until selection.

ASSUNTO(S)

birth weight suinos : landrace litter size seleção puberdade mortality desempenho animal selection peso ao nascer puberty leitegada

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