摘要
本试验旨在研究酵母铬和二氢吡啶对热应激奶牛营养物质消化率及血液生理生化指标的影响。选取胎次、体况、泌乳期相近的荷斯坦奶牛24头,随机分成3组,即对照组(基础饲粮)、酵母铬组[基础饲粮中添加酵母铬80 mg/(头·d)]、二氢吡啶组[基础饲粮中添加二氢吡啶3.0 g/(头·d)],每组8头奶牛。预试期6 d,正试期48 d,整个试验期间温湿指数(THI)高于72。在试验第23~27天进行消化试验,用于测定营养物质消化率;在不同THI(76.7、77.5、78.0、81.0、88.1、85.7、78.9)下采集血样,分别测定血液热休克蛋白70(HSP70)mRNA的表达量,血清三碘甲状腺原氨酸(T3)与四碘甲状腺原氨酸(T4)含量、碱性磷酸酶(ALP)与肌酸激酶(CK)活性以及钠离子(Na+)、钾离子(K+)、氯离子(Cl-)浓度与电解质平衡值。结果显示:1)与对照组相比,酵母铬和二氢吡啶均能显著提高热应激奶牛的干物质采食量和粗蛋白质的消化率(P<0.05),而且酵母铬还能显著提高干物质和中性洗涤纤维的消化率(P<0.05)。2)与对照组相比,酵母铬有上调不同THI下血液中HSP70 mRNA表达量平均值的趋势(P=0.06),并在THI为81.0和88.1时显著提高HSP70 mRNA表达量(P<0.05);二氢吡啶也有上调不同THI下血液中HSP70 mRNA表达量平均值的趋势(P=0.09),并在THI为81.0和85.7时显著提高HSP70mRNA表达量(P<0.05)。3)酵母铬和二氢吡啶对热应激奶牛血清中T3、T4含量和ALP活性没有显著影响(P>0.05)。与对照组相比,在THI为77.5和88.1时,二氢吡啶和酵母铬能显著降低血清中CK活性(P<0.05)。4)与对照组相比,在THI为81.0时,酵母铬和二氢吡啶均能显著提高血清中K+浓度(P<0.05);在THI为78.0时,酵母铬能显著提高血清中Na+浓度(P<0.05);二氢吡啶对血清中Na+浓度无显著影响(P>0.05);酵母铬和二氢吡啶对血清中Cl-浓度均无显著影响(P>0.05);在THI为78.0时,酵母铬能显著提高血清中电解质平衡值(P<0.05);二氢吡啶对血清中电解质平衡值无显著影响(P>0.05)。综上所述,酵母铬和二氢吡啶能提高热应激奶牛的采食量及营养物质消化率,降低血清中CK活性,维持电解质平衡,缓解热应激。
The object of this experiment was to evaluate the effects of yeast chromium and diludin on nutrient digestibility and blood physiological and biochemical indicators of heat stressed dairy cows. Twenty-four lactating Holstein cows with similar parity,body condition and lactation stage were randomly assigned to 3 groups,including control group(basal diet),yeast chromium group [basal diet supplemented with yeast chromium80 mg/(head·d) ] and diludin group [basal diet supplemented with diludin 3 g/(head·d) ],8 cows each group. The experiment had a 6-day adaption period,following a 46-day experimental period. Daily temperature-humidity index(THI) during trial were higher than 72. Digestibility trial was conducted on days 23 to 27 and blood samples were collected at different THI(76.7,77.5,78.0,81.0,88.1,85.7 and 78.9) to measure the heat shock protein 70(HSP70) mRNA expression level and serum the contents of triiodothyronine(T3)and tetraiodothyronine(T4),the activities of alkaline phosphatase(ALP) and creatine kinase(CK),the concentrations of potassium ions(K+),sodion ions(Na+),chloride ion(Cl-),and electrolyte equilibrium value. The results showed as follows: 1) compared with control group,yeast chromium and diludin both significantly increased dry matter intake(DMI) and the digestibility of crude protein(CP)(P<0.05),while yeast chromium also significantly increased the digestibility of dry matter(DM) and neutral detergent fiber(NDF)(P<0.05). 2) Compared with control group,yeast chromium trended to upregulate the mean of blood HSP70 mRNA expression level(P = 0.06) and significantly increased the blood HSP70 mRNA expression level when THI were 81.0 and 88.1(P<0.05);diludin also trended to upregulate the mean of blood HSP70 mRNA expression level(P = 0.09) and significantly increased the blood HSP70 mRNA expression level when THI were81.0 and 85.7(P<0.05). 3) Yeast chromium and diludin did not affect the contents of T3,T4 and the activity of ALP in serum(P>0.05),but significantly decreased serum CK activity compared with control group when THI were 77.5 and 88.1(P<0.05). 4) Compared with control group,when THI was 81.0,yeast chromium and diludin both significantly increased serum K+concentration(P<0.05);when THI was 78.0,yeast chromium significantly increased serum Na+concentration(P<0.05);diludin had no effects on serum Na+concentration(P>0.05);yeast chromium and diludin had no effects on serum Cl-concentration(P>0.05);when THI was 78.0,yeast chromium significantly increased serum electrolyte equilibrium value(P < 0.05);diludin had no effect on serum electrolyte equilibrium value(P>0.05). In conclusion,yeast chromium and diludin can improve the feed intake and nutrient digestibility,decrease the serum CK activity,maintain the electrolyte equilibrium balance and relieve the heat stress of heat stressed dairy cows.
作者
高景
赵传超
李晗
王宇
许宏杨
李蓉
高思
齐智利
GAO Jing;ZHAO Chuanchao;LI Han;WANG Yu;XU Hongyang;LI Rong;GAO Si;QI Zhili(College of Animal Science and Technology,Huazhong Agricultural University,Wuhan 430070,China;Shangdong Dezhou Shenniu Animal Pharmaceutical Co.,Ltd.,Dezhou 253074,China;Enshi Tujia and Miao Autonomous Prefecture Academy of Agricultural Sciences,Enshi 445000,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2019年第12期5719-5729,共11页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家重点研发项目(2016YFD0500507)
湖北省科技支撑计划项目(2014BBA205)
动物营养学国家重点实验室开放项目(2004DA125184F1721)
大北农基金青年学者提升专项
关键词
酵母铬
二氢吡啶
热应激
营养物质消化率
血液生理生化指标
yeast chromium
diludin
heat stress
nutrient digestibility
blood physiological and biochemical indicators
