相对湿度对间歇性偏热环境下肉鸡体温、酸碱平衡及生产性能的影响

Effects of Environmental Relative Humidity at Intermittent Partial Heat Environment on Body Temperature,Acid-Base Balance and Performance of Broilers

本试验旨在研究相对湿度(RH)对间歇性偏热环境下肉鸡体温、酸碱平衡及生产性能的影响。试验采用2个偏热水平(26和31℃)和3个RH水平(30%、60%和85%)的2×3因子设计。选取22日龄爱拔益加(AA)肉鸡360只转入环境控制舱,随机分成6组(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ组),每组6个重复,每个重复10只鸡(公母各5只)。预试期7 d,温度21℃,RH 60%。正试期14 d,从29日龄开始,每天10:00—16:00(6 h),Ⅰ、Ⅱ和Ⅲ组鸡舍环境维持26℃,RH分别为30%、60%和85%;Ⅳ、Ⅴ和Ⅵ组维持31℃,RH分别为30%、60%和85%,剩余时间环境温湿度与预试期相同。结果表明:1)Ⅱ组肉鸡的平均日采食量(ADFI)、平均日增重(ADG)最高,Ⅵ组肉鸡ADFI、ADG最低,各组间料重比(F/G)没有显著的差异(P>0.05)。2)第1、3和10天,Ⅵ组肉鸡的体核温度和皮温最高,Ⅲ组肉鸡的皮温高于Ⅰ和Ⅱ组;第1天,Ⅱ组肉鸡体核温度显著低于Ⅰ和Ⅲ组(P<0.05),第3和10天,Ⅰ、Ⅱ和Ⅲ组间无显著差异(P>0.05)。3)Ⅱ组肉鸡血气中p H和氧分压(p O2)显著低于其他各组(P<0.05),各组二氧化碳分压(p CO2)无显著差异(P>0.05)。由此可见,间歇性偏热环境下(26和31℃),高湿(85%)和低湿(30%)都影响肉鸡的体温、酸碱平衡及生产性能,且不同偏热环境下RH对肉鸡的影响程度不同。

The study was conducted to investigate the effects of relative humidity（ 30%,60% and 85%） on body temperature,acid-base balance and performance of Arbor Acres（ AA） broilers at intermittent partial heat（ 26,31 ℃） environments. A total of three hundred and sixty 22-day-old AA broilers were allotted into environment chambers,and randomly divided into 6 groups（ groups Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ and Ⅵ）,each group（ chamber） contained six cages with ten birds per cage（ with five males and five females）,and each cage as a replicate. The pre-test period lasted for 7 days and broilers were kept at 21 ℃ and 60% relative humidity. The trial lasted for 14 days. When broilers were 29-day-old,the temperature of groups Ⅰ,Ⅱ and Ⅲ were at 26 ℃,regulating the relative humidity to 30%,60%,85%,respectively; the temperature of Ⅳ,Ⅴ,Ⅵ group were at 31℃,while regulating the relative humidity to 30%,60%,85%,respectively. And the temperature and relative humidity of groups were kept six hours each day,at 10： 00—16： 00,after the period,broilers were kept at 21 ℃and 60% relative humidity. The results showed as follows： 1） average daily food intake（ ADFI）,average daily gain（ ADG） in group Ⅱ were the highest among 6 groups. ADFI and ADG in group Ⅵ were the lowest. No significant difference of feed to gain ratio（ F / G） was found among the groups（ P〈0. 05）. 2） On days 1,3 and10,core temperature and skin temperature in group Ⅵ were the highest among 6 groups,and skin temperature in group Ⅲ was higher than that in groups Ⅰ and Ⅱ（ P〈0. 05）. On day 1,core temperature in group Ⅱshowed significantly lower than that in groups Ⅰ and Ⅲ（ P〈0. 05）. On days 3 and 10,there was no significant difference among groups Ⅰ,Ⅱ and Ⅲ（ P〉0. 05）. 3） The p H and oxygen pressure（ p O2） in group Ⅱ were significantly lower than those in other groups（ P〈0. 05）,and no significant difference of carbon dioxide（ p CO2） was found among the groups（ P〈0. 05）. In conclusion,at the intermittent partial heat environment of 26,31 ℃,compared with 60% relative humidity,85% and 30% relative humidity can change the body temperature,acidbalance and performance of broilers. And relative humidity may affect broilers to varying degrees at different partial heat environments.