Pigs' aggressive temperament affects pre-slaughter mixing aggression, stress and meat quality
Pigs' aggressive temperament affects pre-slaughter mixing aggression, stress and meat quality
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DOI：
10.1017/s1751731109991406
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发表时间：
2010-04-01
期刊：
影响因子：
3.6
通讯作者：
Mormede, P.
中科院分区：
文献类型：
--
作者：
D'Eath, R. B.;Turner, S. P.;Mormede, P.
宰前应激对动物福利和肉质有负面影响。当猪被混合在一起运送到屠宰场或到达屠宰场时，攻击性行为是屠前压力的一个重要因素。猪的攻击性在群体中的个体之间存在差异，本研究调查了其对屠宰时应激和肉质的影响。我们在年轻时混合猪，使用先前验证的病变评分方法来识别高(H)或低(L)攻击性气质的个体。为了对比极端的社会压力，将8头单性猪按攻击性在HH、HL或LL组合中混合，或在运输和屠宰前不混合(U)(n=271)。每个处理至少在四个屠宰批次中的每一组中重复两组。混合本身效果不大，但由攻击性猪(HH)组成的混合组在屠宰时有更多的屠体皮肤损伤和更高的血浆皮质醇水平，并且与其他处理相比，24小时的腰肌样本具有更高的pH值，较低的红度(a*)和黄度(b*)。雌性在屠宰时血浆皮质醇水平较高，屠宰后PH值下降更快，肉的瘦肉率更高。性别和处理的交互作用会影响乳酸和肌酸激酶(CK)水平以及肉的pH值。遗传因素、母本和父本组成以及氟烷基因座(ryanodine Receptor 1，RYR1)基因也如预期的那样影响一系列生产和肉质参数。此外，在另外四个屠宰批次中，在没有操纵群体组成的情况下(n=313)，研究了“商业上正常”的社会压力水平。在这些猪中，不熟悉的猪的比例和圈栏组的群体大小解释了屠宰时病变评分的有限差异，但较早的攻击性不能解释。屠体上大量的皮肤损伤与屠宰时皮质醇、乳酸和低血糖水平有关，但与肉类质量指标无关。当比较所有猪的应激和肉质指标时，高乳酸与早期低pH和高滴水损失有关，而高皮质醇和CK与24小时高pH和肉色变化有关。结论，混合具有高于平均攻击性的猪导致更大的攻击性和应激，以及肉质参数的变化，这与屠前应激对肌肉化学的影响一致。
Pre-slaughter stress has a negative impact on animal welfare and on meat quality. Aggressive behaviour when pigs are mixed together for transportation to, or on arrival at, the abattoir is an important factor in pre-slaughter stress. Aggressiveness of pigs varies between individuals in the population, and this study investigated its effects on stress and meat quality at slaughter We mixed pigs at a young age to identify individuals of high (H) or low (L) aggressive temperament using the previously validated approach of lesion scoring. To contrast extremes of social stress single-sex groups of eight pigs were mixed according to their aggressiveness in HH, HL or LL combinations or left unmixed (U) prior to transport and slaughter (n = 271). Each treatment was replicated in at least two groups in each of four slaughter batches. Mixing per se had little effect, but mixed groups composed of aggressive pigs (HH) had more carcass skin lesions and higher levels of plasma cortisol at slaughter and had loin muscle samples with higher pH at 24h, and lower redness (a*) and yellowness (b*) compared to the other treatments. Females had higher levels of plasma cortisol at slaughter; a more rapid decline in pH post-slaughter and greater lean content of meat. Lactate and creatine kinase (CK) levels and meat pH were affected by the interaction of sex and treatment. Genetic factors, dam and sire line composition, and halothane locus (ryanodine receptor 1, RYR1) genotype, also affected a number of production and meat quality parameters as expected. Additionally, 'commercially normal' levels of social stress were studied in four further slaughter batches with no manipulation of group composition (n = 313). In these pigs, the proportion of unfamiliar pigs and group size of lairage groups explained limited variation in lesion scores at slaughter, but earlier aggressiveness did not. High numbers of skin lesions on the carcass were associated with high levels of cortisol and lactate and low glucose at slaughter, but not with meat quality measures. When stress and meat quality measures were compared for all pigs, high lactate was associated with low early pH and high drip loss, while high cortisol and CK were associated with high pH at 24h and changes in meat colour In conclusion, mixing pigs of above average aggressiveness resulted in greater aggression and stress, and changes in meat quality parameters, consistent with the effects of pre-slaughter stress on muscle chemistry