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131.
ZHAO Shoupei LI Xuemei GAO Yuhong SUN Xinsheng GUO Jianjun HAO Zangen MAO Sen 《中国畜牧兽医》2007,47(11):3510-3517
The purpose of this study was to evaluate thermal environment of cowshed in four seasons in central plain of Hebei,and analyze the correlation between the temperature parameters and physiological indexes of dairy cows.Three dairy cow houses with different building structures were selected,the thermal parameters (ambient temperature (Ta) and relative humidity (RH)) and physiological parameters (respiratory rate,rectal temperature and body surface temperature) were detected.The results showed that the Ta,RH and index of temperature and humidity (THI) changed significantly in four seasons (P<0.05),the average daily temperature in summer was the highest (28.59 ℃),and the average daily temperature in winter was the lowest (1.55 ℃).In summer,dairy cows were suffering from mild heat stress for 15.5 h every day,and from moderate heat stress for 6.0 h.In winter,dairy cows were under mild cold stress for an average of 12.0 h per day.The Ta and THI of three cowsheds in each season had no significant differece (P>0.05),except for that in winter.Compared with the cowshed with low wall or roller blind,the average Ta in the cowshed with only roof was 0.80-1.27 ℃ higher in summer and 1.36-1.84 ℃ lower in winter.In addition,the physiological parameters of dairy cows were extremely significantly higher in summer than those in other seasons (P<0.01).The respiration frequency or rectal temperature of cows among cowsheds in summer were significantly different (P<0.05),and the seasonal difference in body surface temperature was significant (P<0.05).Correlation analysis of thermal parameters and cow physiological parameters showed that the respiratory frequency,rectal temperature and body surface temperature were positively correlated with THI and Ta (P<0.05).However,there was no significant correlation between physiological parameters and RH (P>0.05).The results provided scientific basis for environment evaluation of cows,and physiological status of dairy cows were inferred according to environmental thermal parameters,which provided data for occurrence and early warning of stress. 相似文献
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了解牛磺胆酸对发热大鼠体温的影响,并研究其解热作用机理.分别以细菌内毒素、异体蛋白和2,4-二硝基酚致热大鼠,采用荧光分光光度法测定大鼠下丘脑组织中去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)含量;ELISA法测定下丘脑组织中肾上腺素E2(PGE2)含量.牛磺胆酸对细菌内毒素和2,4-二硝基酚所致发热大鼠的体温具有显著的降低作用,而对蛋白胨所致的发热体温作用时间较短;给药组下丘脑中的NE、DA、5-HT和PGE2的含量显著低于对照组.试验证明牛磺胆酸具有显著的解热作用,其作用机理与影响下丘脑组织中NE、DA、5-HT和PGE2的含量有关. 相似文献
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AIM:To determine the migration mode of host lymphocytes into the intestinal graft by analyzing different lymphoid compartments of the graft. METHODS:2, 4, 6 days after transplantation, murine intestinal grafts were harvested for histologic assessment. Lymphocytes were collected from mesenteric lymph nodes (MLN), Peyer’s patch (PP), lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) in the graft for analyzing by cytometry. RESULTS:At the day 2 and day 4, no evidence of rejection in intestinal allograft was found, while the rejection signs were apparent at the 6th day. At day 2 and day 4, host lymphocytes had rapidly replaced donor cell in graft MLN and PP. The migration of host lymphocytes into the LPL and IEL was not as fast as MLN and PP, however, the near-total replacement took place at the 6th post transplant day. The host lymphocytes were activated at the early stage of recruitment into the graft. CONCLUSION:The rapid recruitment of recipient lymphocytes and early activation could be responsible for the formidable rejection of intestinal transplantation. 相似文献
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甲氧基丙烯酸酯类杀菌剂ZJ 0712对黄瓜 白粉病和霜霉病的毒力及药效评价 总被引:3,自引:0,他引:3
ZJ 0712,2- -3-甲氧基丙烯酸甲酯,是我国自行创制的高效广谱杀菌剂。为评价该药剂10%SC对黄瓜白粉病和霜霉病的使用效果,进行了室内和田间药效评价。经室内检测,该药剂对白粉病菌Sphaerotheca fuliginea的EC50和EC90值分别为1.79和 5.47 μg/mL,对霜霉病菌Pseudoperonospora cubensis的EC50和EC90值分别为0.34和 45.15 μg/mL。 田间试验结果表明,该药剂对白粉病在10 ~20 g/hm2、对霜霉病在37.5 ~150 g/hm2剂量下防效分别为85.79% ~91.33%和86.70% ~90.18%。该药剂在本试验剂量范围内对作物安全。 相似文献
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