抗热应激剂的研制及其应用效果试验

Research on Making of Anti - heat Stress Agents and Their Applied Effects

将48头目龄相同、体重（约60kg）相近的杜×长×大三元杂交猪分成对照组、试验1组和2组。试验处理如下：用基粮直接喂对照组猪；在基粮中加0．5％抗热应激剂A后，喂试验1组猪；将基粮中食盐含量降到0．2％，再加0．5％抗热应激剂B后，喂试验2组猪。饲养试验期54d。试验期间，猪舍均温29．64℃，极端温度22℃-39℃；空气平均RH71．55％，空气极端RH 59．1％-90．3％。试验结果如下：（1）使用抗热应激剂的试验1、2组猪体温稳定性能更强。（2）试验1组猪增重极显著地快于对照组（P〈0．01），但试验2组猪增重与对照组无显著差异（P〉0．05）；试验1、2组猪对饲粮养分的转化率均显著地高于对照组（P〈0．05），且试验1组猪对饲粮养分的转化率显著地高于试验2组（P〈0．05）。（3）试验1组猪血糖浓度高于另外两组猪，但差异不显著（P〉0．05）；试验l组猪血清1．P显著地高于另外两组猪（P〈0．05），试验2组猪血清TP虽高于对照组，但差异不显著（P〉0．05）；三组猪血清UN含量的差异不显著（P〉0．05）；试验l、2组猪血清钙、磷、钾含量都略多于对照组（P〉0．05），试验2组猪血清钠含量显著地低于另外两组猪（P〈0．05）；试验1、2组猪血清GOT活性显著地低于对照组（P〈0．05），试验1组猪血清G胛活性显著地低于另外两组猪（P〈0．05）；试验1组猪血清IgG含量显著地高于另外两组猪（P〈0．05）；试验2组猪血清IgG含量也多于对照组，但差异不显著（P〉0．05）。（4）三组猪肌肉中pHu（终点pH值）为5．81—5．89，都在正常范围（5．8—6．2）内；试验1、2组猪肌纤维直径显著地大于对照组（P〈0．05）；试验1组猪肌肉中脂肪、钙、磷含量显著地高于对照组（P〈0．05），试验2组猪肌肉中脂肪、钙、磷含量也多于对照组，但差异不显著（P〉0．05）。根据上述结果可推断：本试验的猪群遭受较严重的热应激；抗热应激剂对维持猪健康有积极的作用，可改善猪营养生化代谢、促进其生长、提高饲粮养分的转化率，并能提高猪肉的品质尤其是猪肉的营养价值；抗热应激剂A较抗热应激剂B的应用效果更好。

48 healthy, weighing about 60 kg, three - way crossbred （ Duroc× Landrace × Yorkshire） finishing pigs were divided into 3 groups. The first and second group were used as experimental groups and fed basal diets supplementing 0.5 % anti - heat stress agent A and B respectively, but the salt of basal diet of the second group was reduced to 0.2%. The control group was fed basal diet of without anti - heat stress agent. The formal experiment lasted 54 d. During the experiment, the extreme temperature of pigpen was 22 - 39℃, and the average temperature was 29. 640C, the extreme RH was 59. 1% - 90.3%, and the average RH was 71.55%. The experimental results were showed as follow： （1）by using anti -heat stress agents ,the back -hair of the two experimental group pigs was rather more polisher than control group, and the animal body temperature was more stable. （2）The anti -heat stress agent A highly markedly promoted growth of pigs （P 〈0.01 ）, but the anti -heat stress agent B had no significant effect on growth of pigs （ P 〉 0.05 ）. The FCR of experimental groups were markedly higher than the control group （ P 〈 0.05） ; the FCR of group 1 was higher than group 2 （ P 〈 0.05 ）. （ 3 ） There was no significant difference in GLU concetrations in serum among all groups （ P 〉 0.05 ）. The finishing pigs of experiment group 1 showed higher level TP in serum than other groups （P 〈 0.05 ） ;TP level in serum of experiment group 2 was higher than the control group, but there was no significant differences （ P 〉 0.05 ）. The serum UN concentration of each experimental group was not significant dif- ferent from that of control group （ P 〉 0.05 ）. There were also no significant differences in Ca , P, K concentrations in serum among all the groups （ P 〉 0.05 ） ; but the Na concentration in serum of the experimental group 2 was lower than the others （ P 〈 0.05 ）. The finishing pigs fed the diet with the anti - heat stress agents showed lower GOT activity in serum than the control group （ P 〈 0.05 ）. The GPT activity in serum of group 1 was markedly lower than the others. The IgG in serum of group 1 was markedly higher than the other two groups （ P 〈 0.05）. And that of group 2 was also higher than the control group, but there was no significant difference （P 〉 0.05 ）. （4） There were no significant differences in back - fat thickness and pH among all groups （ P 〉 0.05）. The calcium,phosphorus and fat in the muscle of group 1 were higher than group 2 and control group （ P 〈 0.05 ） ; and those of group 2 were also higher than the control group , but there were no significant differences （ P 〉 0.05）. According to those results we can conclude ： the pigs were suffered serious heat stress in hot seasons;the anti -heat stress agents have active effects to the health and metabolism of swine, can increase FCR, promote growth of pigs and improve the pork quality, especially the nutritive value of pork ; the anti - heat stress agent A is better than B.