LAUSR

BACKGROUND White striping (WS) is a myopathy of breast muscle (Pectoralis major) that affects the quality and consumer acceptance of breast fillets of broiler chickens. Previous studies have shown that intermittent dilution of dietary nutrients suppress the development of WS on the breast muscle of broiler chickens. However, the mechanism by which these interventions reduce the occurrence of WS remains inconclusive. In this study, we adopted intermittent reduction of dietary digestible lysine (dLys) density or metabolizable energy (ME) and amino acid (AA) density using chemical and fatty acid composition of breast fillets, blood metabolites to understand the mechanism while histopathology and immunohistochemistry of breast muscles were used for confirmation. RESULTS Occurrence of white striping was lower in broiler chickens fed 85% dLys diets in comparison with other groups. Crude protein and ether extract in breast meat of 85% dLys groups were greater (P < 0.001) and lower (P = 0.010), respectively. Serum concentrations of lipid metabolites and enzymes were lower in broiler chickens fed 85% dLys diets than control group (P < 0.05). Feeding 85% dLys diets had low degree of myodegeneration and necrosis, inflammation, lipid deposition, infiltration of T-lymphocyte (CD3+) and macrophages (Iba-1+), and low expression of heat-shock protein 70 (HSP70) than other groups (P < 0.001). CONCLUSION Dilution of dietary dLys to 85% of the required quantities reduces the development of WS in broiler chickens by slowing the growth, lipid synthesis, and muscle damage confirmed by lower extent of histopathological lesions. This article is protected by copyright. All rights reserved.