饲粮能量水平对热应激奶牛营养物质表观消化率及血液生化指标的影响  

Effects of Dietary Energy Level on Nutrients Apparent Digestibility and Blood Biochemical Indices of Dairy Cows under Heat Stress

作　　者：闫方权 薛白[1] 达勒措 宋良荣[1] 王立志[1] 卜登攀[2] 

机构地区：[1]四川农业大学动物营养研究所,动物抗病营养教育部重点实验室,雅安625014 [2]中国农业科学院北京畜牧兽医研究所,北京100193

出　　处：《动物营养学报》2015年第1期103-111,共9页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家科技支撑计划(2012BAD12B02)

摘　　要：为了研究饲粮能量水平对热应激奶牛产奶量、营养物质表观消化率和血液生化指标的影响,本试验采用单因素试验设计,选择25头健康的泌乳中期中国荷斯坦奶牛,随机分为5组,每组5头。各组分别饲喂5种不同能量水平的等氮饲粮,泌乳净能(干物质基础)分别为6.15(组1)、6.36(组2)、6.64(组3)、6.95(组4)和7.36 MJ/kg(组5)。试验期共45 d,预试期15 d,正试期30 d。结果表明:1)提高饲粮能量水平降低了呼吸频率,组4、5极显著低于组1、2(P<0.01),与组3差异不显著(P>0.05)。2)试牛干物质采食量与饲粮能量水平呈显著的负相关关系(R2=0.983 3,P=0.017),组5显著或极显著低于其他各组(P<0.05或P<0.01);产奶量最高的组4与最低的组1比较,提高了9.0%,差异极显著(P<0.01)。3)除钙、磷和总能外,其他养分表观消化率均以组1最高,组5最低,差异显著或极显著(P<0.05或P<0.01)。4)组4血清皮质醇浓度显著或极显著低于组1、2、5(P<0.05或P<0.01),血清内毒素浓度显著或极显著低于其他各组(P<0.05或P<0.01),血清葡萄糖浓度显著高于组1和5(P<0.05);组1、4血清肌酸激酶活性显著或极显著大于组2、3、5(P<0.05或P<0.01),其中组4与组2、3相比分别提高了32.87%和25.40%;血清谷丙转氨酶和谷草转氨酶活性为组1>组2>组4>组3>组5。综合考虑饲粮能量水平对奶牛产奶量、营养物质表观消化率和血液生化指标的影响,热应激条件下泌乳奶牛的饲粮适宜泌乳净能水平为6.95 MJ/kg。In order to investigate the effects of dietary energy level on milk production, nutrients apparent digestibility and blood biochemical indices of dairy cows under heat stress, a single factor experimental design was used. Twenty-five healthy Chinese Holstein dairy cows in mid-lactation were allocated to 5 groups （ 5 cows in each group） corresponding to 5 isonitrogenous dietary treatments with net energy levels [ net energy for lactation （NEL）, dry matter basis] of 6.15 （group 1）, 6.36 （group 2）, 6.64 （group 3）, 6.95 （group 4） and 7.36 MJ/kg （ group 5） , respectively. The experiment lasted for 45 days, including a 15-day pre-experimental period followed by a 30-day experimental period. The results showed as follows： 1） the improving of dietary energy level reduced respiratory frequency, groups 4 and 5 were extremely significantly lower than groups 1 and 2 （ P〈0.01） , and had no significant difference compared with group 3 （ P〉0.05） . 2） There was a significant negative correlation between dry matter intake and dietary energy level （R^2=0.983 3, P=0.017）, and group 5 was significantly lower than the other groups （P〈0.05 or P〈0.01）; milk yield in group 4 was the highest, and was increased by 9% compared with that in group 1 （ group 1 had the lowest value） , the difference was extramely significant （ P〈0.01） . 3） Apparent digestibility of nutrients （ excepted calcium, phosphorus and gross energy） reached the maximum in group 1 and the minimum in group 5, the differences were sig-nificant or extramely significant （ P〈0.05 or P〈0.01） . 4） In group 4, serum cortisol concentration was significantly or extramely significantly lower than that in groups 1, 2 and 5 （P〈0.05 or P〈0.01）, serum lipopo-lysaccharide concentration was significantly or extramely significantly lower than that in the other groups （ P〈0.05 or P〈0.01） , and serum glucose concentration was significantly higher than that in groups 1 and 5 （ P〈0.05）; t

关 键 词：能量水平 热应激 奶牛 表观消化率 血液生化指标 

分 类 号：S823[农业科学—畜牧学]