Evaluation des performances zootechniques du Piétrain stress négatif en croisement industriel

The objective of this study was to evaluate the zootechnical performances (average daily gain, pH of the loin at 45 minutes after slaughter and meat percentage) of Stress-negative Piétrain (Piétrain RéHal) in industrial cross. The effects of genotype (CC, CT TT and Com), sex (male and female), year of fattening (from 1996 to 2004) and cage (37 cages) on the study parameters have been estimated. The observed values ranged from 574.5 to 668.1 g for the average daily gain, from 6.05 to 6.42 for the pH of loin at 45 minutes post mortem, and from 60.10 to 64.29% for the lean percentage. The average daily gain of pig of the commercial line (Com) was higher (from + 87.2 to + 93.7 g), but inversely presented a carcass lean percentage lower than those of CC, CT and TT. The pH of the loin at 45 minutes post mortem of pig CT and Com was similar (6.3 and 6.2 respectively) and hold an intermediate position between CC (6.4) and TT (6.0), even though this value of genotype TT was lower. The male presented a superior growth rate (+ 35.4 g) but a carcass lean percentage inferior (- 1.82 %) to the female one. The sex was not a significant effect on the pH of loin at 45 minutes post mortem (p > 0.05). The fattening year had a significant effect (p < 0.001) on all studied parameters however, without any particularly trend.