Differentially expressed marker genes and glycogen levels in pectoralis major of Ross308 broilers with wooden breast syndrome indicates stress, inflammation and hypoxic conditions

The occurrence of wooden breast (WB) in broiler production is increasing, but onset of its development is only described in part. In this study, we determined the regulation of marker genes related to oxidative stress in Ross308 broilers categorized as no-, mild- or severe-WB, on days 21 and 30 of production. The biochemical parameters, lactate dehydrogenase and pro- and macro-glycogen, were also determined. On day 21, breast meat from birds affected severely by WB had increased mRNA abundances of heat-shock protein 70, heme-oxygenase 1, cyclooxygenase 2, tumor necrosis factor 1, and hypoxia inducible factors as well as higher pH and lower dry matter contents. On day 30, breast meat from both mild and severely affected birds had increased mRNA for heme oxygenase 1, lactate dehydrogenase, and hypoxia inducible factor. Moreover, pro- and micro-glycogen, as well as the total pool of glycogen, were decreased compared with the non-WB birds. In conclusion, this study indicates oxidative stress, inflammation and hypoxic conditions in WB.