高温季节耐热素对猪生产性能与肉质的影响

Effects of Heat-resisting Additive on Production Performance and Meat Quality of Pigs

选取杜×长×大三元杂交肥育猪48头,随机分成3个组。对照组猪喂基础饲粮,试验1组在对照组饲粮基础上加0.5%耐热素A,试验2组在对照组饲粮基础上将食盐的质量分数降到0.2%,再加0.5%耐热素B。试验期为54 d,期间猪舍内最高温度39℃,最低22℃,平均相对湿度为71.6%。结果表明:两试验组猪的体温均在不同程度上低于对照组猪,但差异不显著(P>0.05)。耐热素A对猪增重有促进作用(P<0.05);耐热素A、B对饲料转化率都有改善作用(P<0.05),其中耐热素A比B的效果更明显。试验1组猪肌肉中脂肪、钙的含量都显著高于试验2组和对照组(P<0.05);试验2组猪肌肉中脂肪、钙的含量亦高于对照组猪(P>0.05)。试验1、2组猪肌肉纤维直径均大于对照组(P>0.05)。3个组猪背膘厚和肌肉pH值无显著的差异(P>0.05)。这说明,耐热素A在减轻高温对猪健康和生产性能的不良影响有明显的效果,且可促进脂肪、钙在肌肉内沉积,对改善猪肉的风味也有一定的积极作用。

48 crossbred （ Druoc × Landrace × Yorkshire） finishing pigs were randomly divided into 3 groups. Pigs in the control group were fed with basal diet, pigs in Group l were fed with basal diet containing 0.5% heat-resisting additive A, and pigs in Group 2 were fed with basal diet, of which salt content was reduced to 0.2% and for which 0.5% heat-resisting additive B was added. The test period is 54 days, during which, the highest temperature in pigsties is 39℃, the lowest is 22℃, and the mean relative humidity is 71.6%. Results showed that the body temperature of pigs in two treatment groups is lower than that of pigs in the control group in various degree, but the difference is insignificant （ P 〉 0.05 ）. Heat-resisting additive A has promoted the gain in weight of pigs （ P 〈 0.05 ） ; both heat-resisting additive A and B have improved the feed conversion rate （ P 〈 0.05 ） , and heat-resisting additive A had more obvious effects than heat-resisting additive B. The calcium and fat contents in muscle of pigs in Group I are remarkably higher than those of pigs in Group 2 and in the control group （P 〈0.05） ; the calcium and fat contents of pigs in Group 2 were also higher than those of pigs in the control group （ P 〉0.05 ）. The diameter of muscle fiber of both Group l and Group 2 were bigger than that of pigs in the control group （ P 〉0.05 ）. There were no significant differences in back-fat thickness and pH value of muscle among three groups（ P 〉 0.05 ）. The results proves that heat - resisting additive A can obviously alleviate the bad effects of high temperature on pigs health and production performance, promote the deposition of fat and calcium in muscle, and improve pork flavor in certain degree.