抗热应激添加剂对奶牛产奶量、生理及血液指标的影响

为研制一种有效的奶牛抗热应激添加剂，将50头健康荷斯坦奶牛随机分为5组，对照组饲喂基础日粮，4个试验组饲喂基础日粮添加不同抗热应激添加剂，连续饲喂30d，测定产奶量、生理及血液指标。结果显示：中草药组、中草药＋纤维素酶组、中草药＋缓冲盐组、中草药＋缓冲盐＋纤维素酶组比对照组产奶量分别提高24．8％、27．9％、37．2％、39．5％；中草药剂和缓冲盐可减缓热应激奶牛的体温（P〉0．05）、呼吸和心率（P〈0．05）的升高，缓解外周血中自细胞数（WBC）、淋巴细胞数（LYM）、单核细胞数（MXD）、淋巴细胞百分比（LYM％）和单核细胞百分比（MXD％）（P〈0．05）的变化；添加中草药剂组肾上腺皮质醇（Cort）、促肾上腺皮质激素（ACTH）、三碘甲状腺原氨酸（T3）和甲状腺素（T4）水平基本稳定（P〉0．05）；使用中草药添加剂组谷胱甘肽过氧化物酶（GSH—Px）活性比对照组下降较慢（P〈0．05），添加中草药加缓冲盐组GSH—Px活性可基本保持稳定（P〉0．05）。试验表明中草药剂可明显增强奶牛抗热应激力，和瘤胃缓冲盐同用效果更好，和纤维素酶同用作用不明显。

Effects of Anti-heat Stress Additives on Milk Yields, Physiology and Blood Parameters of Cows

In order to research a kind of effective anti-heat stress additive for cow, 50 healthy Holstein Cows were divided randomly into five groups. The control group was fed with basal diet, four test groups had been fed with basic diet and different anti-heat stress additives for continuous 30 days, then the milk yields, physiology and blood indexes were determined. The results showed ： as compared with the control group, the four test groups improved respectively with mild yelds of 24.8 % ,27.9 % ,37.2 % ,39.5 %. The chinese herbal medicine agent and rumen buffer salt could alleviate the increasing of heat-stress cows＇ rectum temperature （ P 〉 0.05 ）, heart rate and respiratory frequency （ P 〈 0.05 ） , and relieved the changes of WBC,LYM ,MXD,LYM % and MXD % （P 〈 0.05 ） in peripheral blood. The levels of Cort ,ACTH ,T3 and T4 were basically stable in cows fed with chinese herbal medicine agent （P 〉 0.05 ）. The activity of GSH-Px decreased much slower in cows which were added chinese herbal medicine agent than the control group （ P 〈 0.05） , and were basicly stable in cows which were added Chinese herbal medicine and rumen buffer salt（ P 〉 0.05 ）. The experiment result shows that the chinese herbal medicine agent can enhance significantly anti-heat stress ability, adding rumen buffer salt the effects are better, but adding cellulose enzyme there is no obvious effect.