饲养方式对AA鸡屠宰后胸脯肌肉和腿肌肉僵直过程理化特性的影响

Effects of breeding mode on changes of physicochemical characteristics in breast and leg muscles of post-mortem Arbor Acres broiler

目的研究笼养和散养方式对AA鸡宰后24h内胸脯肌肉和腿肌肉理化特性的影响。方法随机选择同一批相同饲养水平散养和笼养的AA鸡各30只。按照商业屠宰方法屠宰后,鸡胴体冰水冷却1.5h,然后,4℃冷藏至宰后24h。宰后0、3、6和24 h时取样,分别测定pH值、肌糖原含量、肌节长度、R-值和肌原纤维小片化指数(MFI)。结果笼养鸡比散养鸡活体重高8.17%,且笼养鸡体重较均一。在宰后僵直过程中笼养鸡胸脯肌肉和腿肌肉pH值和肌糖原含量降低速度分别比散养鸡快。笼养鸡胸脯肌肉进入僵直比散养鸡胸脯肌肉早,但是笼养鸡腿肌肉进入僵直时间比散养鸡腿肌肉晚。笼养和散养鸡不管是胸脯肌肉之间,还是腿肌肉之间,其肌节长度和MFI之间没有显著差异。并且宰后24h,本实验所测定指标在笼养和散养鸡之间不存在显著差异。结论饲养方式(笼养和散养)除了对AA鸡活体重以外,对屠宰后胸脯肌肉和腿肌肉的理化特性没有显著影响。

Objective To investigate the effects of the cage feeding and the graze feeding modes on broiler physicochemical properties during post-mortem period.Methods Breast and leg muscles were obtained from thirty 45-day-old chickens in cage and grazing groups respectively.Chickens were slaughtered in the commercial way,the broiler carcasses were chilled in ice water for 1.5 h,and then chilled until 24 h post-mortem in condition of 4 ℃.Samples were obtained at post-mortem 0,3,6 and 24 h.The pH,R-value,glycogen content,sarcomere length and myofibrillar fragmentation index(MFI) were determined.Results The live weight of the cage group was heavier than that of grazing group,which was up to 8.17%,and the live weight of cage group was more uniform.The development of rigor in breast muscles of cage group was faster than grazing group one,but the leg muscles were reverse.However,there were no significant differences in sarcomere length and MFI of both muscles between cage group and grazing group.Further more,there is no significant difference between cage group and grazing group at the 24 h post-mortem.Conclusion Rearing patterns(cage feeding and graze feeding) can affect weight only,but have no effect on the physicochemical properties of the breast and leg muscles at the 24 h post-mortem.