冷热应激对蛋鸡生理生化指标的影响

Effects of Ambient Temperature Stress on Physiological and Biochemical Index in Layers

１８周龄的伊莎蛋鸡在１３～１８℃、６０％～７０％ＲＨ的环境条件下，饲养至２３周龄（产蛋率为７０％）时，随机分为８组，（每组８只），用于模拟蛋鸡在南京地区自然急性冷热应激条件下的部分生理生化指标变化。试鸡分别在３０℃－７０％ＲＨ、３５℃－７０％ＲＨ、３５℃－９０％ＲＨ和２℃－５５％～７２％ＲＨ条件下进行试验，每种处理均设有一组适宜温度组为对照，试验期均为７天。结果表明，急性热应激时，蛋鸡血液的ＰＣＶ、ＰＣＯ２、ＬＤＨ的活性、血糖、血清钙、Ｔ４、Ｔ３和Ｅ－１７β的含量均与对照组有显著（Ｐ＜００５）或极显著（Ｐ＜００１）降低；直肠温度较对照组有极显著升高（Ｐ＜００１）。急性冷应激时，蛋鸡直肠温度较为恒定，血液ｐＨ、ＰＣＯ２、Ｈｂ、ＰＣＶ、血糖、Ｃｏｒ含量和ＬＤＨ活性略有升高，但除血糖外差异均不显著（Ｐ＞００５），血清钙、Ｔ４、Ｔ３和Ｅ－１７β的含量降低，且Ｔ４和Ｅ－１７β的含量与对照组差异极显著（Ｐ＜００１）。

Eighteen Weeks old ISA pullets were raised in 13～18℃ and 60%～70% RH to 23 Weeks old and their egg production rate reaching 70 percent,and then were randomly divided into eight groups for examining the physiological and biochemical index when exposed to natural acute heat or cold stress in Nanjing region.Eight for each group were given 30℃ and 70%RH、35℃and 70%RH、35℃ and 90%RH、2℃ and 55%～72%RH respectively,control groups were still raised in the optimal temperature and humidty.The results showed:PCV、PCO 2,activity of LDH,glucose,serium calcium,T 4、T 3,cortisol and E-17β of hens in acute heat stress were signficantly(P<0.05) or high significantly (P<0.01) lower than controls ,while the rectal temperature increased significantly higher (P<0.01).For cold stress treatment,their rectal temperatures were kept constantly,pH、PCO 2、Hb、PCV,glucose,cortisol and activity of LDH were not increased more(P>0.05).serium calcium,T 4、T 3 and E-17β were reduced,E-17β and T 4 were high significantly lower (P<0 01) than controls