运输应激状态猪血液皮质醇含量与肉质性状之间的关联性分析

试验旨在研究商品猪血液中皮质醇含量与宰后的胴体性状和肉质表观指标之间的相关性并探讨其内在联系。在具有秋季典型气温时间（2012年8月20日），选取120头商品猪，猪只运输时间约为2h，运输到屠宰场后休息1．5h后屠宰，取血液样品测定皮质醇含量，取背最长肌测定肉质指标，并测定猪只的胴体重和背膘厚。根据测定得到的皮质醇浓度，将猪只分成三个组，低皮质醇组（〈120ng／mL）、中皮质醇组（120～130ng／mL）和高皮质醇组（〉130ng／mL），比较三组之间肉质和胴体指标之间的差异。结果表明，在肉质指标方面，除中皮质醇组猪只的24h的电导率有升高的趋势（P=0．08）外，其余均无显著差异；在胴体性状方面，高皮质醇组胴体重极显著高于（P〈0．01）低皮质醇组，高皮质醇组背膘厚显著高于（P〈0．05）低皮质醇组，与中浓度皮质醇组差异均不显著。猪只血液中皮质醇含量与胴体重和背膘厚度都存在着极显著的正相关，相关系数分别为0．349和0．274。各肉质指标之间也存在相关性，其中PH与电导率为极显著的负相关，pH与肉色的L值呈极显著的负相关，45min时测定的肉色L值与滴水损失相关系数为0．234，猪只胴体重和背膘厚度呈极显著的正相关关系，相关系数为0．596。结果提示，无法通过猪只血浆皮质醇浓度的高低来评估宰后猪肉品质，但一定程度内较高的皮质醇浓度会有利于个体增重和背部脂肪的沉积。

Correlativity Analysis of Plasma Cortisol Concentrations and Meat Quality and Carcass Traits of Commercial Pigs

This experiment was designed to study the relationship between the cortisol concentrations and carcass traits and meat quality of commercial pigs and to explore its internal relations. Samples of commercial pigs in the slaughterhouse on a day with typical temperature in the autumn were collected. 120 pigs were chosen to be transported to slaughterhouse for about 2 hours and they were slaughtered after 1. 5 hours＇ rest. The cortisol concentrations of plasma, meat quality, carcass weight and backfat thickness were measured. According to the cortisol concentrations in plasma, those pigs were divided into three groups：

High cortisol concentrations group （〉130 ng/mL）, Intermediate cortisol concentrations group （120~130 ng/mL）, Low cortisol concentrations group ？120 ng/rnl.）, The differences on meat quality and carcass traits among three groups were studied. The results show that, the conductivity at 24h in medium cortisol group showed an uptrend compared with that in other groups （P=0. 08）, and the rest meat quality indicators were not significantly different. The carcass weight in high cortisol group were significantly higher than that in low cortisol group （P〈0. 01）, the back fat thickness in high cortisol group were significantly higher than that in low cortisol group （P〈0. 05） but were not significantly with medium cortisol group. The cortisol concentrations had a significant positive correlation with carcass weight and backfat thickness. The correlation coefficients were respectively 0. 349 and o. 274. There is also a correlation between meat quality indicators. The p H and conductivity were highly negatively correlated, so were p H and L-value. The correlation coefficient between L45min and drip loss was 0. 234. Carcass weight and backfat thickness showed a highly significant positive correlation and the correlation coefficient was 0.596. The results suggest that we can＇t predict meat quality after slaughter through the cortisol concentrations in plasma. But to a certain extent high cortisol levels will be conducive to individual weight and back fat deposition.