【摘要】：為緩解南方夏季高溫高濕熱應激對肉牛生產性能的影響,研究不同降溫方式對肉牛舍的降溫效果,探討屋面噴淋通風降溫系統(tǒng)緩解熱應激的機理。以江西省地方品種錦江黃牛為試驗對象,選擇24頭年齡、體重相近、性別相同、生長狀況良好的錦江黃牛,隨機分為3組,每組8頭牛,試驗1、2和3組分別為舍內通風組、舍內噴霧通風組和屋面噴淋通風組,分別測定了環(huán)境溫度、濕度,肉牛直腸溫度、呼吸頻率和日增質量、血液生化指標、免疫指標和無機離子等相關參數等。研究結果如下:1屋面噴淋通風降溫系統(tǒng)對牛舍溫熱環(huán)境和肉牛生產性能的影響屋面噴淋運行期間(10:00-18:00),與1組相比,3組舍內距屋頂0、1、2和3 m處溫度分別降低4.79℃(P0.01)、2.13℃、1.37℃和1.42℃;濕度分別增加9.66%(P0.01)、6.76%(P0.01)、2.66%和1.80%;在14:00時,距離地面高度1.5 m和0.5 m分別降低1.2℃(P0.05)和1.07℃;呼吸頻率降低12次/min(P0.01);直腸溫度差異不顯著;日增質量提高了26.38%(P0.05)。噴霧運行期間14:00時,與1組相比,2組肉牛體感溫度噴霧前后分別降低0.51℃和1.43℃(P0.05),在18:00分別下降0.70℃和1.60℃(P0.05);呼吸頻率降低13次/min(P0.01);直腸溫度差異不顯著;日增質量提高提高了11.11%。2屋面噴淋通風降溫系統(tǒng)對肉牛血液生化指標的影響與第1 d相比,三碘甲狀腺原氨酸(T3)含量,1組在試驗第15 d和31 d分別降低5.68%和8.52%,3組在15 d和31 d則分別提高了1.65%和5.49%;甲狀腺原氨酸(T4)的含量,1組在試驗第15 d、31 d差異不顯著,3組在第31 d時提高了14.48%(P0.05);皮質醇(COR)含量,1組差異不顯著,但有上升趨勢,3組則有下降趨勢,且第31 d與第1 d相比差異極顯著(P0.01);胰島素生長因子(IGF-I)含量,1組第31 d下降了4.93%,3組則提高了9.98%;血糖(GLU)含量,1組第15 d和31 d分別提高了2.30%和5.75%,2組分別提高了6.63%和19.83%;總蛋白(TP)、白蛋白(ALB)和球蛋白(GLO)含量,1組在第15 d和31 d均有所下降,3組TP、ALB、GLO均有所上升;免疫球蛋白M(IgM)含量,1組均有所下降,3組上升顯著;1組無機離子均有下降趨勢,3組均有上升趨勢,但差異不顯著。從以上結果可以得出,屋面噴淋通風降溫系統(tǒng)可以一定程度緩解肉牛的熱應激,改善肉牛舍的溫熱環(huán)境,降低呼吸頻率和體感溫度,提高生產性能和經濟效益。通過屋面噴淋通風降溫可有效改善肉牛機體的代謝紊亂,提高肉牛抵抗力。
[Abstract]:In order to alleviate the effect of high temperature and high humidity heat stress on the performance of beef cattle in southern summer, the cooling effect of different cooling methods on beef house was studied, and the mechanism of reducing heat stress in roof spray ventilation cooling system was discussed. A total of 24 Jinjiang cattle with similar age, similar weight, same sex and good growth condition were randomly divided into 3 groups (8 cattle per group). The environmental temperature, humidity, rectum temperature, respiration frequency and daily gain, blood biochemical index, immune index and inorganic ion were measured in indoor spray ventilation group and roof spray ventilation group. The results are as follows: 1 the effect of roof spray ventilation and cooling system on the thermal environment and the performance of beef cattle during the roof spraying operation period (10: 00-18: 00). The temperatures at 2 and 3 m decreased by 4.79 鈩，

本文編號：2351931