Estimation of the genetic parameters of meat characteristics and of their genetic correlations with growth and body composition in an experimental broiler line

Genetic paramters of breast meat characteristics [pH 15 min postmortem (pH( 15min)), ultimate pH (pHu), CIELAB color parameters (L*, lightness a*, redn ess; b*, yellowness) and drip loss (DL)] as well as their genetic correlati ons with BW and body composition [breast yield (BRY) and abdominal fat perc entage (AFP)] were estimated in an experimental meat-type chicken line. Her itability of the pH of meat was high for pHu (0.35 +/- 0.03) and even more so it pH(15min) (0.49 +/- 0.01). Color parameters appeared to be the most h eritable traits, with heritability values ranging from 0.50 to 0.57. Drip l oss heritability was estimated at 0.39 +/- 0.04. The rate and the extent of pH decline seemed to be controlled by different genes, as shown by the ext remely low estimated genetic correlation (0.02 +/- 0.04) between pH(15min) and pHu. The ultimate pH of the meat was genetically very strongly related to its lightness (-0.91 +/- 0.02) and water-holding capacity (-0.83 +/- 0.0 4). These results suggest that selection for pHu could be exploited to prev ent increased incidence of pale and exudative meat. The pH(15min) was poorl y correlated with the other meat characteristics, with estimated correlatio ns of 0.13, -0.23, 0.05, and -0.29 for L*, a*, b*, and DL., respectively. T hese results may be explained by the fact that, in our experimental conditi ons, pH(15min) remained high (between 6.01 and 6.75). Body weight and BRY e xhibited poor genetic correlations (ranging from -0.06 to 0.13) with the pH of the meat at 15 min and 24 h postmortem. Both of the former traits were moderately negatively correlated with a* and b* values. A significant negat ive genetic correlation was observed between abdominal fatness and pHu. The se results do not support the idea that selection for growth and breast dev elopment has a detrimental effect on breast meat quality even if, in the lo ng term, the color intensity could be decreased.