Genetic variability within and between breeds of poultry technological meat quality

The increasing importance of the technological quality of meat, defined as its ability to be stored or further-processed, has highlighted the need for research work on the genetic control of meat characteristics, which has been seldom studied in poultry until now. Both the variabilities of quality indicators between genetic types and within populations in selection are being studied. These complementary approaches aim at defining the possibilities of a genetic improvement of meat quality and the relationships with growth performances of the birds. This implies a better knowledge of the mechanisms involved in meat quality, in order to identify the most relevant criteria of selection. Results obtained up to now in chickens lead to the consensual conclusion that the increased breast mass obtained by genetic selection has mainly been achieved by an increased fibre size, while no changes in the metabolic profile were detected. According to the genetic parameters obtained up to now, the technological quality of the meat could be efficiently improved by the genetic route. Indeed, heritabilities of quality characteristics obtained in the chicken under experimental conditions are high. At the same time, the estimated correlations do not show any genetic antagonism between the birds' performances and the quality of their meat. All these results thus favour selection on the quality of the meat, even if its implementation remains in the hands of the breeders, according to the return in terms of competitiveness. According to the available results, the ultimate pH could be a relevant criterion of selection because of its strong relationship to the colour, the water-holding capacity or the texture of the meat. Much research however remains to be undertaken to optimise the efficiency of selection on the quality of the meat. In particular, interactions with pre-slaughter stresses must be specified, as they can strongly affect meat quality. On the other hand, it is hoped that significant progress in the methods of selection based on the quality of the meat will be brought by the identification of molecular markers of meat quality.