Reduction of Ribonucleotide Reductase Subunit RRM2 Potentially Impairs Gut Function of Woody Breast Broilers

Woody breast (WB) condition impairs the texture and appearance of chicken breast meat causing major losses for the industry each year. Recent studies showed that mineral supplementations improve WB indicating that gut health may play a role. Ribonucleotide reductase, subunit RRM2, is involved in mitochondrial function, and downregulating it increases gastrointestinal disturbances and liver toxicity. This study attempted to investigate links between RRM2 and gut health in broilers with WB. Tissues were collected from 15 severe WB and 15 normal birds. Results indicated that WB increased pH, drip loss, compression force, redness, and hemorrhages in breast meat. RRM2 expression was reduced, and several oxidative damage factors including thiobarbituric acid increased in the duodenum and liver of WB broilers. Expression of genes related to mitochondrial function and gut barrier function in the duodenum and liver were reduced in WB broilers. WB broilers had shorter villi length and thicker crypt resulting in lowered villi/crypt ratio. Digestive enzyme activities and ATP concentrations were altered in the duodenum and liver of WB broilers. Overall, reduced RRM2 expression impaired mitochondrial function leading to increased inflammation and altered gut morphology and enzyme activities, suggesting that RRM2 may play an essential role in gut health and WB myopathy development.