Wooden breast (WB) myopathy is a pathology of the pectoralis major muscle. Wooden breast is caused by multiple factors. The exact etiopathogenesis of this myodegenerative pathology is still unclear. Fast-growing commercial lines of broilers that are selected for high breast muscle yields are more susceptible to this myopathy. The biochemical analysis of blood is used to diagnose pathologies and understand disease processes. Therefore, the objective of this research was to determine and compare the changes in the blood serum biochemical parameters of Ross 308 chicken broilers without myopathy and those affected by WB myopathy. Blood samples were collected from male and female Ross 308 broilers that were 43 days old, with an average live weight of 2.98–3.09 kg. Representative blood samples were selected from broilers with WB (n = 33) and without WB (n = 33). In the laboratory, the blood was centrifugated, and biochemical tests were performed with an automated computerized biochemistry analyzer. The research results showed that broilers with WB had elevated blood serum levels of creatine kinase (CK) (p = 0.018), potassium (p = 0.010), and alanine aminotransferase (ALT) (p = 0.012). In conclusion, elevated serum levels of CK and potassium indicated that skeletal muscle cells were damaged. Moreover, increased ALT levels suggested a possible association between WB myopathy and liver damage. Additionally, these research findings underscore the diagnostic significance of CK and hint at its potential as a WB biomarker.

The objectives of this research were to highlight the main factors, which have relevant significance for etiology of myopathies and to assess the incidence of myopathies in a representative population of broilers raised in Lithuania. Eighteen flocks were evaluated to assess the incidence of musculus pectoralis major myopathies (PMM) (total 54,000 broilers) and dorsal cranial myopathy (DCM) (total 124,200 broilers). Thirteen flocks (total 19,500 broilers) were evaluated to find out deep pectoral myopathy (DPM) occurrence in Lithuania. Investigated parameters of each flock were: average broiler live body weight (BW) at slaughter, average slaughter age, treatment and seasons. A correlation analysis was used to measure the strength of the linear relationship between the investigated traits and incidence of these myopathies. Overall, the incidence of PMM in Lithuania was 18.19%. DCM and DPM were 5.16% and 0.27%, respectively. The percentage of PMM in flocks was strongly associated with average broiler live BW at slaughter (r=0.898, p<0.001) and age at slaughter (r=0.693, p<0.001). The percentage of PMM in flocks was negatively related with treatment of broilers (rs=-0.535, p<0.05). The percentage of DCM was positively associated with average broiler live BW at slaughter (r=0.537, p<0.05) and with seasons (rs=0.658, p<0.01). However, our study results revealed, that the analyzed parameters are not so important in DPM etiology. Furthermore, predisposing factors of PMM, DCM and DPM are different. These findings suggest that not only broiler's heavy weight and age at slaughter could have influence for etiology of myopathies.

The aim of this research was to determine the impact of pectoralis major myopathies on the physical parameters, fatty acid (FA) profile, and volatile organic compound (VOC) composition of chicken breast meat. Samples were collected from pectoralis major of broilers with varying severity scores (normal, mild, and severe) of wooden breast (WB) and white striping (WS) myopathies. Chicken breast meat affected by severe myopathies expressed higher cooking loss, drip loss (p < 0.001), and yellowness (p < 0.05) compared to those of samples that were taken from broilers without myopathies (normal). The amount of monounsaturated fatty acids (MUFAs) was significantly higher in samples affected by mild and severe myopathies than in those without myopathies (p < 0.05). There was significantly more aldehyde hexanal in muscles affected by mild and severe myopathies than in muscles without myopathies (p < 0.05). In conclusion, WB and WS myopathies of the breast muscle not only affected the physical parameters of broiler meat but also may have influenced its FA profile and VOC composition. Additionally, an elevated amount of hexanal in muscles affected by WB together with WS suggests that oxidative stress could be important in the etiopathogenesis of WB and WS myopathies. Therefore, poultry meat affected by myopathies have the potential to alter breast meat flavor and composition.