Enhancing key broiler welfare indicators, meat quality, and gut microbiome composition using oxygen-enriched drinking...

Water is a critical nutrient in poultry production, yet its quality, particularly dissolved oxygen (DO) content, is often overlooked. This study is the first to comprehensively evaluate the impact of oxygen-enriched drinking water on broiler welfare, breast muscle myopathies, and gut microbiome composition under commercially relevant housing conditions. A total of 840 male Ross 308 broiler chicks were randomly assigned to two treatment groups (oxygenated water vs. tap water), with 12 replicate pens per treatment. Oxygenated water was enriched to a DO level of approximately 32 mg/L, compared to around 9.5 mg/L in tap water. Birds were reared to 36 days of age. The consistently high performance of both treatment groups under controlled experimental conditions is demonstrated by final body weights and feed conversion ratios surpassing Ross 308 breed standards by approximately 19-22 % from day 24 onward. Although growth performance remained unaffected under these optimal conditions, oxygenated water significantly improved welfare indicators, including feather condition, hock burn scores, and breast cleanliness (P< 0.05). Birds on oxygenated water also showed lower abdominal fat (-12 %) and higher thigh yield (+2.6 %) without compromising breast yield. Carcass fat deposition was significantly lower (abdominal fat pad reduced by ∼12 %), and thigh yield was higher in the oxygenated water treatment (P < 0.05), although overall carcass weight and breast yield were unchanged. No major differences were detected in breast meat nutrient composition (P > 0.05). The prevalence of white striping in breast fillets was markedly reduced in birds receiving oxygenated water, 32 mg/L indicating enhanced muscle integrity (P < 0.05). Metagenomic analysis revealed that some bacterial lipid metabolism pathways where differentially abundant in oxygenated-water birds. Following up on previous knowledge suggesting the interplay between lipid metabolism and broiler welfare, these findings suggest that supplementing broiler drinking water with 32 mg/L DO levels may offer a practical, non-pharmaceutical strategy to mitigate breast muscle myopathies and improve overall animal welfare and meat quality.