肉牛舍不同蒸发降温技术的卫生学评价

发布时间：2018-06-06 03:19

本文选题：蒸发降温 + 肉牛舍　；参考：《南京农业大学》2015年硕士论文

【摘要】：家畜温度、湿度、太阳辐射以及风速等因素构成了家畜的温热环境。温热环境严重制约家畜健康与生产。了解热应激危害,并针对改善畜舍小气候采取蒸发降温技术,可缓解肉牛热应激,对提高家畜生产水平具有十分重要意义。第一部分旨在探讨喷雾吹风系统在南方畜舍内降温效果。随机选择两个畜舍,分为试验组和对照组。试验组安装风机喷雾系统,对照组安装传统吊扇。试验进行6天,每天08:00-19:00打开降温系统。每天10:00、14:00和18:00测量环境指标和生理指标。结果表明:试验畜舍环境温度3个时间段分别低于对照组1.61、1.75和1.32℃,风速显著高于对照组(p0.05),两个畜舍温湿指数没有显著差异。对照畜舍一氧化二氮、氨气和一氧化碳浓度分别高于试验畜舍3.8%、8.7%和6.7%。在10:00、14:00和18:00,试验组肉牛呼吸速率分别低于对照组13、21.4和20.5次/min,试验组肉牛直肠温度分别低于对照组0.33、0.39和0.28℃,试验组肉牛皮温分别低于对照组1.76、2.37和0.68 ℃。综上所述,喷雾吹风系统能够降低畜舍环境温度,显著降低肉牛呼吸速率、直肠温度和皮温,缓解肉牛热应激,有益于提高夏季肉牛健康与生产。第二部分旨在评价上置冷风管通风模式防暑降温效果。选择尺寸相同两栋牛舍,对照组安装吊扇,试验组安装冷风机-风管系统。分别选取10头健康成年西门塔尔肉牛作为试验家畜。每天10:00、14:00和18:00时间分别测量环境指标和生理指标,试验周期7天。结果表明:冷风机-风管降温系统显著提高畜舍内平均风速(p0.05),降低畜舍温度(p0.01);冷风机-风管系统可以显著降低肉牛呼吸速率8.8和14.4次/min,降低直肠温度0.38和0.46 ℃,降低肉牛皮温1.66和1.83;试验组相对湿度、C02和NH3分别高于对照舍30.21%、7.0%和14.31%,空气质量符合相关行业标准的要求。综上所述,冷风机-风管系统可以显著降低畜舍环境温度,缓解肉牛热应激,在南方肉牛舍降温方面具有极大推广价值。第三部分旨在研究头部降温对肉牛生理作用以及第二日早晨肉牛生理变化。分别机选择8头健康西门塔尔肉牛分为两组,每组各4头。每一个降温循环包括先进行20-s喷淋然后10-min强制吹风。试验组共进行10次循环。对照组不做任何处理。每两个循环为一组,分别测量环境指标、呼吸速率、直肠温度和皮温。试验Ⅰ在每天12:00-15:00进行降温处理,试验Ⅱ在每天12:00-15:00和17:00-19:00进行降温处理。试验Ⅱ前日晚上进行降温处理(17:00-19:00),在第二日6:00、7:00、8:00、9:00和10:00分别测量各项生理指标。结果表明:试验Ⅰ温湿指数均高于88,家畜处于热应激状态。肉牛呼吸速率快速下降,经过10个降温循环,降低了 23.4次/min,显著低于对照组。试验Ⅱ温湿指数低于62,表明肉牛处于非热应激状态。试验组呼吸速率快速下降,最大降低21.6次/min。对照组中呼吸逐渐上升,显著高于试验组(p0.01)。试验Ⅰ和Ⅱ中试验组直肠温度低于对照组,但是差异不显著。热应激条件下,头部局部降温显著降低家畜不同部位皮温1.24-1.85 ℃。非热应激条件下,肉牛皮温维持相对稳定,对照组皮温快速升高,显著高于试验组。前日傍晚头部降温,次日早晨肉牛的直肠温度稳定在较低水平,呼吸速率和皮温升高减慢。综上所述头部局部降温显著降低肉牛呼吸速率和皮温,缓解肉牛热应激。同时,傍晚头部降温会降低次日肉牛体温和呼吸速率,缓解高温影响。
[Abstract]:Livestock temperature, humidity, solar radiation and wind speed and other factors constitute the warm environment of domestic animals. The warm environment seriously restricts the health and production of domestic animals. To understand the hazards of heat stress, and to improve the heat stress of cattle, it is of great significance to improve the production level of domestic animals. The effect of the spray blowing system in the southern barn was investigated. Two barns were randomly selected to be divided into experimental and control groups. The experimental group installed the fan spray system and the control group installed the traditional ceiling fan. The experiment was carried out for 6 days, and the cooling system was opened by 08:00-19:00 every day. The environmental indicators and physiological indexes were measured at 10:00,14:00 and 18:00 every day. The results showed that: The 3 time periods of the experimental animal environment temperature were lower than the control group 1.61,1.75 and 1.32 C, the wind speed was significantly higher than that of the control group (P0.05), and the temperature and humidity index of the two barns had no significant difference. The concentration of ammonia and carbon monoxide was higher than the experimental barn 3.8%, 8.7% and 6.7%. at 10:00,14:00 and 18:00, respectively. The rate of 13,21.4 and 20.5 /min were lower than that of the control group. The rectal temperature in the test group was lower than that of the control group 0.33,0.39 and 0.28, respectively. The skin temperature of the beef cattle was lower than the control group 1.76,2.37 and 0.68 C, respectively. In conclusion, the spray blowing system could reduce the ambient temperature of the livestock, lower the rate of beef respiration, the rectal temperature and the skin temperature, and alleviate the temperature. The heat stress of beef cattle is beneficial to improve the health and production of beef cattle in summer. The second part aims to evaluate the effect of heat stroke in the ventilation mode of the upper cold wind pipe. Select the same two bull houses with the same size, the control group installation ceiling fan, the test group install the cold air fan and the wind pipe system. 10 healthy adult Simmental beef cattle are selected as the experimental livestock, respectively. Every day, 10:00,1 The environmental indicators and physiological indexes were measured at 4:00 and 18:00 respectively. The test period was 7 days. The results showed that the cooling fan air duct cooling system significantly increased the average wind speed (P0.05) in the livestock house and reduced the temperature of the barn (P0.01), and the cold fan air duct system could significantly reduce the rate of respiration of beef cattle by 8.8 and 14.4 times /min, and lower the rectal temperature 0.38 and 0.46 degrees. The skin temperature of meat and cattle was 1.66 and 1.83, and the relative humidity of the test group, C02 and NH3 were 30.21%, 7% and 14.31% respectively, and the air quality met the requirements of the related industry standards. In summary, the cold fan wind pipe system could significantly reduce the temperature of the livestock environment, alleviate the heat stress of beef cattle, and have a great promotion value in the cooling of South beef cattle. Part of the purpose was to study the physiological effects of head cooling on beef cattle and the physiological changes of beef cattle on the morning of second. 8 healthy Simmental beef cattle were divided into two groups, each of which was 4 heads each. Each cooling cycle included 20-s spray first and 10-min forced blow. The experimental group carried out 10 cycles. The control group did not do any treatment. Every two treatment. The cycle was a group of environmental indicators, respiration rate, rectal temperature and skin temperature. Test I was cooled at 12:00-15:00 every day. The test II was cooled at 12:00-15:00 and 17:00-19:00 every day. The test II was cooled on the day before the night (17:00-19:00), and each item was measured at 6:00,7:00,8:00,9:00 and 10:00 on second days, respectively. The results showed that the temperature and humidity index of the test I were all higher than 88, and the animals were in the state of heat stress. The respiration rate of beef cattle decreased rapidly, and after 10 cooling cycles, 23.4 times /min was reduced, which was significantly lower than that of the control group. The temperature and humidity index of the experiment II was lower than 62, indicating that the beef cattle were in the non thermal stress state. The respiration rate of the experimental group decreased rapidly and the maximum decreased by 21.. In the 6 /min. control group, the respiration increased gradually, significantly higher than the test group (P0.01). The rectal temperature in the test group I and the test group was lower than the control group, but the difference was not significant. The local temperature of the head decreased significantly at 1.24-1.85 C under the condition of heat stress. The temperature of the flesh and cattle skin remained relatively stable under non heat stress conditions, and the skin of the control group was relatively stable. The temperature of the head was significantly higher than that in the test group. The temperature of the head was cool in the evening, and the temperature of the rectum of the beef cattle was stable at the lower level, and the respiration rate and the skin temperature slowed down the following morning. The rate of respiration relieves the effect of high temperature.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823

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