Phenotypic Correlations in Broiler Breast Meat Quality and some Welfare Criteria: Implications of Photoperiod Length and Light Intensity

The goals of this research were to estimate the phenotypic correlations among various meat quality traits, carcass parts weight, some blood parameters, and eye dimensions from a male broiler line and to describe the relation among these variables. Two photoperiod length groups and two light intensity groups of com-mercial meat-type broilers were used as treatments. A total of 272 1 day-old male broiler chicks (Ross 308) were randomly assigned to four treatment groups based on the photoperiod length and light intensity, with four replicates. Eight broilers from each group were used for colour measurement (CIE L*a*b*), pH, cook-ing loss, and water holding capacity at the age of 42 days. The pH at 24 hours after postmortem (pHu) was capable of directly interfering with the attributes of the meat, since this trait was inversely related with a*, water holding capacity and pH 15 mins postmortem (pH15) in the dim, reducing (DRLI) group, indicating an effect of pHu decrease during 24h postmortem on protein denaturation. This study demonstrates that the variables of poultry meat quality are related and that there is a phenotypical association between a* value, water holding capacity (WHC) and the other attributes of the meat. The pHu, a* value and WHC could be efficient meat quality indicators in this broiler line. Corticosterone (CORT) level had a significant positive correlation (r=0.323, P<0.05) with glucose level in the bright light (BLI) group. Eye weight had a signifi-cant correlation with all eye dimensios in increasing photoperiod length group.