运输和静养时间对肉鸡应激程度及肌肉品质的影响

Effects of time in transport and lairage rest on stress level and meat quality in broiler

将180只AA肉鸡随机分配到9个处理组中,设定运输时间(0.5、3和5 h)、静养时间(0、1和2 h)2因素3水平,每处理4个重复,每重复5只鸡,研究不同运输时间和静养时间对肉鸡应激程度及肌肉品质的影响。结果表明:血液应激指标中血糖(GLU)含量随运输时间延长而降低;5 h运输后不静养组鸡血液中乳酸(LD)含量最高;3 h运输后2 h静养组肉鸡血液中乳酸脱氢酶(LDH)活性最高;3 h运输后静养各组肉鸡血液中肌酸激酶(CK)活性显著高于其余处理组(P<0.05),并在静养1 h时达到最大;皮质酮激素(CORT)和促肾上腺皮质激素(ACTH)含量均随静养时间延长呈下降趋势,3 h运输后2种激素含量显著提高(P<0.05),5 h运输后略有下降并与0.5 h运输后激素水平相近。肌肉品质指标中5 h运输各组鸡胸肉表面亮度值(L*)显著高于其他运输时间组(P<0.05);红度值(a*)随运输时间延长逐渐减小;3 h运输各组相对其他运输时间内相同静养时间组鸡胸肉表面黄度值(b*)较高,并在静养1 h达到最大;鸡胸肉pH值随运输时间延长呈降低趋势,但静养时间对pH值影响不显著(P>0.05);滴水损失随运输时间延长而增大,5 h运输后不静养组在各处理组中滴水损失最大,静养时间对滴水损失影响较小。

180 AA broilers were assigned to 9 treatments randomly which included 2 factors and 3 levels of transport time （0.5,3 and 5 h）and lairage rest time（0,1 and 2 h）. Each treatment consisted of 4 replicates with 5 broilers each for investigating the effects of time in transport and lairage rest on stress level and meat quality in broilers. The results showed that among plasma stress parameters, glucose（GLU） concentration decreased as transport time extended. The level of lactic acid（LD） was highest in the treatment with 5 h transport and no lairage rest. After 3 h transport and 2 h lairage rest ,plasma lactate dehydrogenase（LDH） activities reached the highest level. The ereatine kinase（ CK）activities in the treatments with 3 h transport and lairage rest were higher than in the other treatments （P〈0. 05 ）and the highest level was shown in the treatment with 3 h transport and 1 h lairage rest. Plasma corticosterone（CORT） and adrenocortieotropie hormone（ ACTH） contents tended to decrease as lairage rest time became longer. After 3 h transport, the level of CORT and ACTH increased to the highest（P〈0.05 ） ,but decreased after 5 h transport,to the same level as the 0.5 h treatment. Among meat quality parameters, the lightness value（ L ＊ ）of the broiler breast in the treatments with 5 h transport was higher than with the other two transport time（P〈0.05）. The redness value（ a＊ ）decreased with extended transport time while the yellowness value（ b ＊ ）of the treatments with 3 h transport was higher than with the other two transport time with the same lairage rest time. The treatments with 3 h transport and 1 h lairage rest had the highest b ＊ value. The pH of breast meat had a downward trend with extended transport time and was not affected by lairage rest time（P〉0. 05 ）. Drip loss value increased as transport time extended. The treatments with 5 h transport and no lairage rest showed the highest drip loss while lairage rest time had less effect on it.