Estimation of the Genetic Parameters of Meat Characteristics and of Their Genetic Correlations with Growth and Body Composition in an Experimental Broiler Line

Abstract

Genetic parameters of breast meat characteristics [pH 15 min postmortem (pH15min), ultimate pH (pHu), CIELAB color parameters (L*, lightness; a*, redness; b*, yellowness) and drip loss (DL)] as well as their genetic correlations with BW and body composition [breast yield (BRY) and abdominal fat percentage (AFP)] were estimated in an experimental meat-type chicken line. Heritability of the pH of meat was high for pHu (0.35 +/- 0.03) and even more so for pH15min (0.49 +/- 0.01). Color parameters appeared to be the most heritable traits, with heritability values ranging from 0.50 to 0.57. Drip loss 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 extremely low estimated genetic correlation (0.02 +/- 0.04) between pH15min 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 +/- 0.04). These results suggest that selection for pHu could be exploited to prevent increased incidence of pale and exudative meat. The pH15min was poorly correlated with the other meat characteristics, with estimated correlations of 0.13, -0.23, 0.05, and -0.29 for L*, a*, b*, and DL, respectively. These results may be explained by the fact that, in our experimental conditions, pH15min remained high (between 6.01 and 6.75). Body weight and BRY exhibited 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 negative genetic correlation was observed between abdominal fatness and pHu. These results do not support the idea that selection for growth and breast development has a detrimental effect on breast meat quality even if, in the long term, the color intensity could be decreased.

Genetic parameters of�meat technological quality traits in�a�grand-parental commercial line of�turkey

“…In addition, the lightness of breast meat would also be significantly genetically correlated to the ultimate pH of the muscle in accordance with a previous study in the chicken [17]. The strong negative genetic correlation between pH 20 and L * was a consistent result since both traits are potential indicators of PSE meat.…”

“…In pigs, the existence of separate mechanisms was supported by the results of several genetic studies showing poor to moderate genetic correlations between pH after slaughter and ultimate pH [8,15,25]. A very low genetic correlation was found in the chicken too [17]. Further investigations in poultry would be useful to elucidate the mechanisms underlying the relationship we observed in the present study, between the rate and the extent of post-mortem pH fall in the breast muscle.…”

“…Few studies have reported the heritability of the rate of pH fall in poultry. Indeed, only one estimate has been published by Le Bihan-Duval et al [17] in chickens, using animals reared and killed under experimental conditions. The heritability of pH measured at 15 min postmortem in the breast meat was then estimated at a high value (0.49), which could suggest different genetic determinisms according to the poultry species.…”

“…By contrast with pigs, the genetic determinism of meat quality in poultry is poorly defined. Interestingly, significant levels of heritability were obtained for several meat quality traits in chickens in a recent study reporting first estimates of genetic parameters [17]. However, this experiment was realised under highly controlled experimental conditions, which did elicit the expression of meat quality defects.…”

Does the chicken genotype ‘Géline de Touraine’ have specific carcass and meat characteristics?

“…This character could be under a genetic control as previously reported by Harms et al (1977), Scholtyssek (1978) and Fletcher (2002) for the skin, and related to the ability to store carotenoid pigments. Le Bihan-Duval et al (2001) obtained a heritability of 0.55 for b* parameter measured on the breast muscle of experimental chicken lines divergently selected on breast yield and abdominal fat percentage. More recently, Nadaf et al (2007) identified, on the experimental breeds used to produce EC chickens, quantitative trait loci (QTLs) controlling redness and yellowness of breast meat.…”