Developments in turkey meat harvesting technologies

Genetic Parameters of White Striping and Meat Quality Traits Indicative of Pale, Soft, Exudative Meat in Turkeys (Meleagris gallopavo)

Due to the increasing prevalence of growth-related myopathies and abnormalities in turkey meat, the ability to include meat quality traits in poultry breeding strategies is an issue of key importance. In the present study, genetic parameters for meat quality traits and their correlations with body weight and meat yield were estimated using a population of purebred male turkeys. Information on live body, breast, thigh, and drum weights, breast meat yield, feed conversion ratio, breast lightness (L*), redness (a*), and yellowness (b*), ultimate pH, and white striping (WS) severity score were collected on 11,986 toms from three purebred genetic lines. Heritability and genetic and partial phenotypic correlations were estimated for each trait using an animal model with genetic line, hatch week-year, and age at slaughter included as fixed effects. Heritability of ultimate pH was estimated to be 0.34 ± 0.05 and a range of 0.20 ± 0.02 to 0.23 ± 0.02 for breast meat colour (L*, a*, and b*). White striping was also estimated to be moderately heritable at 0.15 ± 0.02. Unfavorable genetic correlations were observed between body weight and meat quality traits as well as white striping, indicating that selection for increased body weight and meat yield may decrease pH and increase the incidence of pale meat with more severe white striping. The results of this analysis provide insight into the effect of current selection strategies on meat quality and emphasize the need to include meat quality traits into future selection indexes for turkeys.

Effect of the exposure to oxidation and malondialdehyde on turkey and rabbit meat protein oxidative stability

The present study aimed at evaluating the effect of the exposure to a strong oxidative environment (100 mM NaClO) and the concurrent incubation with different malondialdehyde (MDA) concentrations (0 to 5 mM) on protein carbonylation, free thiol groups, total heme pigments, and on the relative concentration of the different myoglobin (Mb) derivatives in turkey thigh and rabbit hind leg meat to elucidate their eventual role in inducing oxidative modifications on the protein fraction. With regard to turkey meat, the addition of a strong oxidant resulted in remarkably higher (P < 0.001) carbonyls along with a reduction in free thiol groups (which become undetectable). The relative concentration of MbO₂ and MetMb was significantly affected (P < 0.001) and total heme pigment was reduced by 62% when fresh meat is compared to its oxidized counterpart. The addition of MDA 2.5 mM (or greater) resulted in a 1.4-fold increase in carbonyls and a tendency (P = 0.07) has been observed for free thiol groups whose content decreased as the MDA level increased. Overall, the aforementioned results are in agreement with those obtained on rabbit hind leg meat in which a three-fold increase (P < 0.001) in carbonyls and a remarkably higher (P < 0.001) MetMb content coupled with a 53% reduction in free thiol groups were found. No significant differences ascribable to MDA addition were found. In conclusion, exposing turkey and rabbit meat to the same environment resulted in distinctive oxidative changes that might be related to the compositional traits and a species-specific susceptibility of the meat toward oxidation. PRACTICAL APPLICATION: Protein and lipid oxidation have been investigated in different meat types; nevertheless, the knowledge concerning the interaction between these two phenomena is limited. According to their compositional traits (high Polyunsaturated fatty acids (PUFA) and heme pigment content), turkey and rabbit leg meats are particularly susceptible to oxidation. Providing information concerning the oxidative stability of turkey thigh and rabbit hind leg meat exposed to strong oxidative conditions and to a concurrent increasing content of a secondary product of lipid oxidation, the findings of the present study can be useful when proper processing strategies and storage conditions have to be implemented for manufacturing processed products.

Muscle Abnormalities and Meat Quality Consequences in Modern Turkey Hybrids

Turkey meat is the second most consumed poultry meat worldwide and represents an economic source of high-quality protein for human consumption. To fulfill the increasing demand for turkey meat, breeding companies have been selecting genetic lines with increased growth potential and breast muscle proportion. Moreover, the progressive shift toward further processed products has emphasized the need for higher standards in poultry meat to improve its technological characteristics and functional properties (i.e., water-holding capacity). However, as observed for broiler chickens, a growing body of scientific evidence suggests that the intense selection for the aforementioned traits could be associated with a greater occurrence of growth-related myopathies and abnormalities and, consequently, to increased downgrading rates and overall reduction of meat quality characteristics. In the past, muscle abnormalities such as deep pectoral myopathy, pale-soft-and-exudative-like meat, and focal myopathy have been reported in turkey lines selected for increased growth rate. In addition, the presence of white striations in the superficial layer of pectoralis major muscle, as well as the tendency of muscle fiber bundles to separate resulting in an altered breast muscle structure, has been detected in commercial turkey abattoirs. Furthermore, past investigations revealed the presence of another quality issue depicted by an overall toughening of the breast muscle. These meat abnormalities seem to macroscopically overlap the white striping, spaghetti meat, and wooden breast conditions observed in pectoral muscle of fast-growing, high-breast-yield chicken hybrids, respectively. Considering the high economic impact of these growth-related abnormalities in broilers, there is an increasing interest of the turkey industry in estimating the occurrence and the impact of these meat quality issues also in the modern turkey lines. Studies have been recently conducted to assess the effect of the genotype on the occurrence of these emerging growth-related defects and to evaluate how meat quality properties are affected by white-striping condition in turkeys, respectively. Therefore, this review aims to provide a critical overview of the current understanding regarding the growth-related abnormalities and their impact on meat quality in modern turkey hybrids with the hope that this information may improve the knowledge concerning their overall effect on poultry meat.

Electrical stunning parameters: impact on the quality of turkey meat (Meleagris gallopavo)

Pre-slaughter conditions can interfere with the quality of meat. Proper stunning systems can minimize the occurrence of meat anomalies. The goal of this study was to assess the effects of electrical stunning parameters on the quality of turkey meat. Nine assays were conducted, with varying frequency, current, and voltage. The variables assessed in the assays were incidence of bruising, bleeding, blood splash and contusions, pH, color, water holding capacity, and shear force. A high incidence of bruising was observed in the breasts (25.0-57.1%) and carcasses (52.5-58.5%) of the turkeys. The pH of the turkey breasts ranged from 5.9 to 6.0 and the shear force ranged from 13.9 to 18.4 N. The frequencies had different effects on the assessed variables, leading to the formation of two groups: group 1-low frequencies (50-200 Hz) and group 2-high frequencies (633-1500 Hz). The incidence of anomalies in the turkey breast and carcasses was higher in group 1 than in group 2. The use of frequencies to stunning below 200 Hz tends to increase blood spots, fractures/contusions and bruising in turkey meat.