Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is di...Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines（leptin and adiponectin）, AMP-activated protein kinase（AMPK）, and heat shock signal molecules（heat shock transcription factor（HSF） and heat shock proteins（HSP）） in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment： eighteen lactating Holstein dairy cows were used. The treatments were： heat stress（HS, THI average=81.7, n=9） and cooling（CL, THI average=53.4, n=9）. Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment： HS treatment cows（n=9） from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90（P〈0.05）. Adiponectin is strongly associated with AMPK. The increases of adiponectin and AMPK may be one of the mechanisms to maintain homeostasis in heat-stressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dai展开更多
为改善在夏季高温时奶牛场的自动降温状况,设计了一种实用且有效的自动降温系统,采用LabVIEW设计基于MODBUS协议的上位机软件,运用MODBUS模拟量采集模块采集温湿度变送器的信息,利用温湿指数(temperature and humidity index,THI)控制...为改善在夏季高温时奶牛场的自动降温状况,设计了一种实用且有效的自动降温系统,采用LabVIEW设计基于MODBUS协议的上位机软件,运用MODBUS模拟量采集模块采集温湿度变送器的信息,利用温湿指数(temperature and humidity index,THI)控制喷淋器的开启和关闭,实现奶牛场的自动降温。测试结果表明:设计的自动降温系统降温效果良好,实行喷淋降温的试验组奶牛呼吸频率与对照组相比,最高降低18次/min,最低降低1次/min。展开更多
基金Project supported by the National Basic Research Program(973)of China(No.2011CB100805)the Modern Agro-Industry Technology Research System of China(No.nycytx-04-01)the Agricultural Science and Technology Innovation Program(No.ASTIP-IAS12),China
文摘Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines（leptin and adiponectin）, AMP-activated protein kinase（AMPK）, and heat shock signal molecules（heat shock transcription factor（HSF） and heat shock proteins（HSP）） in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment： eighteen lactating Holstein dairy cows were used. The treatments were： heat stress（HS, THI average=81.7, n=9） and cooling（CL, THI average=53.4, n=9）. Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment： HS treatment cows（n=9） from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90（P〈0.05）. Adiponectin is strongly associated with AMPK. The increases of adiponectin and AMPK may be one of the mechanisms to maintain homeostasis in heat-stressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dai
文摘为改善在夏季高温时奶牛场的自动降温状况,设计了一种实用且有效的自动降温系统,采用LabVIEW设计基于MODBUS协议的上位机软件,运用MODBUS模拟量采集模块采集温湿度变送器的信息,利用温湿指数(temperature and humidity index,THI)控制喷淋器的开启和关闭,实现奶牛场的自动降温。测试结果表明:设计的自动降温系统降温效果良好,实行喷淋降温的试验组奶牛呼吸频率与对照组相比,最高降低18次/min,最低降低1次/min。
