Research On The Metabolic Characteristics Of Wooden Breast And White Striping In Broiler Chickens

Recently,wooden breast(WB)and white striping(WS)arouse broad concern of global poultry industry due to their increasing incidences and negative effects on meat quality.WS is characterized by the occurrence of white fat striations parallel to muscle fibers,while WB is mainly featured with obvious hardening of breast fillets.WB and WS may occur individually or in concert with each other.These myopathies are associated with the alterations of metabolic mechanisms,however data on the metabolic characteristics of WB and WS is still limited.To further elucidate the metabolism characteristics of the WB and WS affected chicken,non-targeted lipidomics and targeted carbon metabolomic are used in this study.The experimental results will provide a theoretical reference for illustrating the metabolic mechanism of WB and WS.One hundred and 150 male broilers from fast-growing white feather chicken were selected for sample collection at 28 and 42 day of age,respectively.The breast fillets were assessed by subjective scoring,compression force(CF)and histopathology,then 155 breast fillets were screened in this experiment which including 28 d abnormal breast muscle(only WB),42 d abnormal breast muscle(WS,WB and WB+WS groups)and two normal control groups of 28 and 42 day.The results showed that the CF of abnormal groups was significantly higher than the control groups(P<0.001),and the CF positively correlated with the scores at 42 day.The serum creatine kinase(CK)value increased significantly with the rising of CF(P<0.001)and positively correlated with CF(r=0.608;P<0.001)at 42 day.The linear regression equation(CK=0.9960*CF+1.884)was established.In conclusion,our study found that serum CK could be a biomarker of the WB and WB+WS affected chicken,while DG(16:0),PA(14:0)and PC(18:0E)were owned by WB+WS group.A total of 120 breast muscle,liver and serum samples from the above groups(28 d abnormal and control group,42 d abnormal and control group)were detected by Ultra Performance Liquid Chromatography-Mass Spectrometer,and 560,434 and 529 lipid molecules were identified in the three tissues,respectively.Compare with the corresponding control group,the average significant different lipid molecules in the breast muscle of the 28 d abnormal group,42 d abnormal groups(WS,WB and WB+WS)are 44 and 220,respectively.The average significant different lipid molecules in the liver of the 28 d abnormal group,42 d abnormal groups(WS,WB and WB+WS)are 22 and 62,respectively.The average significant different lipid molecules in the serum of the 28 d abnormal group,42 d abnormal groups(WS,WB and WB+WS)are 56 and 21,respectively.Compare with the 28 d abnormal group,the quantity of significant different lipid molecules in breast muscle and liver of the 42 d bnormal groups increased about 5 times and 2.8 times respectively.However,the number of significant different lipid molecules in the serum decreased about 2.5 times.It was speculated that the alterations of lipid metabolism in the liver were involved,but the metabolic disturbance of WB and WS affected chickens were mainly concentrated in the breast muscle.The dominant lipid profile alterations of the breast muscle showed decreased phospholipids at 28 day and were characteristics with the increased neutral lipids and the decreased phospholipids and sphingolipids at 42 day.The content of monounsaturated fatty acid in the breast muscle was significantly increased,while the content of polyunsaturated fatty acid and saturated fatty acid in the breast muscle was significantly decreased.The alterations of fatty acid of neutral lipid make great contribution to the change of fatty acid composition in the breast muscle.TG(18:2),TG(18:1)and TG(16:0)were the main difference lipids in WB,WS and WB+WS group.The specific difference lipids in WB group included PC(20:5)and PE(20:5).DG(18:1),TG(22:1)and DG(18:2)were the specific difference lipids of WS group,A total of 80 breast muscle and liver from the above groups(28 d abnormal and control group,42 d abnormal and control group)were detected by Liquid Chromatography and Mass Spectrometry,and 98 and 120 metabolites were identified respectively.Compare with the corresponding control group,the average significant different metabolites in the breast muscle of the 28 d abnormal group,42 d abnormal groups(WS,WB and WB+WS)are 10 and 15,respectively.The average significant different metabolites in the liver of the 28 d abnormal group,42 d abnormal groups(WS,WB and WB+WS)are17 and 4,respectively.Compare with the 28 d abnormal group,the quantity of significant different lipid molecules in breast muscle of the 42 d abnormal group increased about 1.5 times.However,the number of significant different lipid molecules in the liver decreased remarkably.These results showed that the metabolic disturbance of WB and WS affected chickens were mainly concentrated in the breast muscle.The significant different metabolites of the breast muscle included glucose,amino acids,organic acids and adenosine,and the enrichmented metabolic pathways included the up regulation of glutathione metabolism,TCA cycle and amino sugar metabolism.In conclusion,this study found CK could be a biomarker of WB and WB+WS affected chickens.The relative abundance of lipid molecules(about 40%)and the relative abundance of carbohydrate and other metabolites(about 15%)in the breast muscle were significantly changed.The dominant lipid profile alterations in the WS,WB and WB+WS breast muscle are characteristics with the increased neutral lipids and decreased phospholipids and sphingolipids.