【摘要】 选择2～4胎次泌乳中期的荷斯坦牛48头,配对分为4组,每组12头:CK（基础日粮）、Ⅰ组（基础日粮+400 g脂肪酸钙）、Ⅱ组（基础日粮+2.5 kg苜蓿干草）和Ⅲ组（基础日粮+400 g脂肪酸钙+2.5 kg苜蓿干草）,于7～9月进行50 d的饲养试验,以研究添加脂肪酸钙或（和）苜蓿干草对热应激奶牛生产性能和血液指标的影响。结果表明:（1）添加脂肪酸钙或（和）苜蓿干草可以减缓热应激条件下奶牛产奶量的下降,提高产奶量,其中,Ⅲ组产奶量极显著高于CK（P<0.01）;（2）添加脂肪酸钙或（和）苜蓿干草有提高乳脂率的趋势（P>0.05）;（3）有提高血清T₄和COR水平的趋势（P>0.05）,且Ⅲ组血清T₃含量显著高于CK（P<0.05）。更多还原

【Abstract】 48 healthy Holstein cows in parturition numbers of 2～4 and mid-lactation stage were randomly divided into 4 groups of 12 cows each,to carry out a 60 d feeding trial to study effects of calcium soaps of fatty acids and alfalfa hay on performance and blood indexes of heat - stressed dairy cows.The 4 groups were appointed as control group（basal diet）,group 1(400 g·d^-1 calcium soaps of fatty acids),group 2(2.5 kg·d^-1 alfalfa hay) and group 3(400 g·d^-1 calcium soaps of fatty acids and 2.5kg·d^-1 alfalfa hay).Results:（1） Adding calcium soaps of fatty acids or（and） alfalfa hay lessens the heat stress induced decline tendency of milk yield;the milk yield of group 3 is extra significantly higher than that of control group（P<0.01）.（2） The milk fat content trends to increase with addition of calcium soaps of fatty.acids or（and ） alfalfa hay（P>0.05 ）.（3） The level of thyroxine （T₄） and Cortisol（COR） in serum trends to increase（P>0.05）,and the level of triidothronine（T₃） of group 3 increases significandy（P<0.05） compared with control group.更多还原