动物营养学报2017，Vol.29Issue(10)：3514-3522,9.DOI:10.3969/j.issn.1006-267x.2017.10.012
不同相对湿度对连续日增温下肉仔鸡生理指标的影响
Effects of Different Relative Humidity on Physiological Indices of Broilers under Continuous Increasing Temperature
摘要
Abstract
In this study, the effects of different relative humidity ( RH) on the physiological indices of broilers under increasing temperature environment were studied. One hundred and eighty 22?day?old Arbor Acres ( AA) male broilers were allotted into environment controlled chambers and randomly divided into 3 groups with 6 replicates per group and 10 chickens per replicate. Adaptation period lasted for 7 days, and the tempera?ture was 20 ℃ while the RH was 60%. When the broilers were 29?day?old, RH was adjusted to 35%, 60%and 85% of three groups, respectively, until the end of this trial. The temperature in the environment controlled chambers was rises by 2 ℃ per day, and the trial period was 9 days. When the broilers were 37?day?old, the temperature in the environment controlled chambers was 38 ℃. During the experiment period, the broilers fed and drank water ad libitum, and non?contact physiological indicators were measured, while there was no stress to chickens. The results showed that there was inflection point temperature ( IPt) in core temperature ( CT) , earlobe temperature ( ET) , leg temperature ( LT) , respiratory rate ( RR) , feed intake ( FI) and drinking wa?ter ( DW) . The first indicator of reaction was LT, and the temperature was in the range from 24.6 to 25.1 ℃, followed by ET and CT, while the temperature was in the range from 25.0 ℃ to 25.1 ℃ and 25.5 to 26.4 ℃each. RR had two IPts (IPt1 and IPt2) which were in the range from 25.5 to 27.2 ℃ and 32.5 to 33.3 ℃. RR was increased with the increasing temperature above IPt1 , while decreased with increasing temperature above IPt2. FI and DW were changed in the range from 27.1 to 29.3 ℃ and from 29.2 to 29.5 ℃ respectively, FI and DW were decreased with increasing temperature above IPt. The IPt of FI in high humidity group was sig?nificantly higher than those in middle and low humidity group ( P<0.05) . The IPt2 of mortality rate ( MR) in high humidity group was significantly lower than those in middle and low humidity group ( P<0.05) . The IPts of CT, ET, LT, RR, FI and DW under high humidity were lower than those in middle and low humidity group. RH had no significant effect on ET, LT, RR and DW model parameters (P>0.05). In conclusion, ambient temperature strongly affects the physiological indices of broilers, whereas RH has a relatively minor effects on it. The upper critical temperature can be considered to be the IPt above which FI decreased and RT then increased. The upper critical temperatures of 4 to 5 weeks old broilers are from 25.5 to 26.4 ℃for CT, from 25.5 to 27.2 ℃ for RR decreased, from 27.1 to 29.2 ℃ for FI increased, and from 32.7 to 33.5 ℃ for death. When the broiler died, the differences between the highest value of CT and the constant values are in the range from 4.6 to 5.1 ℃. The 4 to 5 weeks old male broilers have different upper critical temperatures for dif?ferent physiological indices.关键词
肉仔鸡/湿度/日增温/拐点温度Key words
broiler/humidity/increasing temperatures/inflection point temperature分类
农业科技引用本文复制引用
李萌,厉秀梅,周莹,冯京海,赵骞,张敏红..不同相对湿度对连续日增温下肉仔鸡生理指标的影响[J].动物营养学报,2017,29(10):3514-3522,9.基金项目
国家"十三五"重点研发计划课题"肉禽舒适环境的适宜参数及限值研究"(2016YFD0500509) （2016YFD0500509）
动物营养国家重点实验室自主研究课题"热环境影响肉鸡健康生长的分子机制"(2004DA125184G1609) （2004DA125184G1609）
