围产期山羊血钙稳恒与胃肠道CaBP-D9k表达对不同日粮阴阳离子差的响应研究  

Responses of Blood Calcium and Calcium Binding Proteins-D9k Expression Level to Dietary Cation-anion Difference of Transition Goats

作　　者：杨艺[1] 张吉鹍 莘海亮[1] 田兴舟[1] 韩晓洁[1] 段永邦 王代林 吴文旋[1] 李胜利 

机构地区：[1]贵州大学动物科学学院,贵阳550025 [2]贵州省凯里市畜牧兽医管理办公室,凯里556000 [3]贵州省长顺县敦操乡,长顺5507000 [4]动物营养学国家重点实验室,北京100193

出　　处：《畜牧兽医学报》2014年第6期932-942,共11页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金(30901038;31160468;31360658);动物营养学国家重点实验室开放课题(2004DA125184F1115)

摘　　要：本试验旨在研究不同日粮阴阳离子差(Dietary cation-anion difference,DCAD)对围产期山羊血浆Ca2+和胃肠道钙结合蛋白9kDa(Calcium binding proteins 9kDa,CaBP-D9k)表达水平的影响,探索低DCAD日粮预防围产期奶牛低血钙的可能机制。将27头围产期贵州黑山羊随机分为3组,每组9头,分别饲喂3组DCAD日粮:高DCAD(HD,+325)日粮组、对照组(CON,+179)、低DCAD(LD,-110)日粮组。在产前10d、产羔当天、产后3d分别采血并屠宰山羊,检测其血浆离子指标与胃肠道CaBP-D9k表达水平。结果表明,与高DCAD日粮相比,低DCAD日粮不影响山羊采食,酸化了山羊尿液pH(P<0.05),提高了整个试验期内血浆Cl-水平(P<0.05)。孕期内,山羊血浆Ca2+浓度随日粮DCAD水平的降低而增加(P<0.05),采食低DCAD日粮导致了更高的产后血浆Ca2+浓度(P<0.05)。除回肠、盲肠及直肠外,低DCAD日粮较高DCAD日粮明显上调山羊胃肠道其余区段内CaBP-D9kmRNA表达水平(P<0.05),并缓和了产后皱胃、空肠与回肠CaBP-D9kmRNA表达水平的降幅(P<0.05)。由此可见,低DCAD日粮有利于维持围产期山羊血浆Ca2+稳恒,伴随胃、十二指肠、空肠及结肠肠段CaBPD9kmRNA表达水平的上调,表明上述区段的钙吸收能力得到增强。这可能是低DCAD日粮有效维持围产期奶牛血浆Ca2+稳恒的作用机制。The study was conducted to clarify the mechanism of low dietary cation-anion difference(DCAD)level preventing hypocalcemia in transition cows by investigating the influence of DCAD levels on blood Ca concentration and calcium binding protein-9kDa(CaBP-D9k)expression level in gastrointestinal tract of transition goats.Twenty-seven Guizhou Black goats in transition period were randomly allocated to 3treatments with 9goats each treatment and were fed 3diets with varying DCAD levels:high DCAD(HD,+325),control(CON,+179)and low DCAD(LD,-110)groups,respectively.Goats were blooded on d 10before lambing,d 0for lambing and d 3afterlambing,respectively,and were slaughtered to detect the plasma parameters and CaBP-D9kexpression level of gastrointestinal tract.Compared with high DCAD,feed intake was unaffected by low DCAD treatment(P>0.05),urine pH of goats fed LD was reduced with decreasing DCAD level(P<0.05).Compared to CON and HD,reducing DCAD level induced higher plasma Cl-and Ca2+concentration of goats during the experiment(P<0.05).Greater CaBP-D9kmRNA expression level was observed in whole gastrointestinal tract of LD-fed goats except for ileum,cecum and rectum compared with goats in HD group(P<0.05).Moreover,feeding LD diet relieved the decline of CaBP-D9kmRNA expression level in abomasum,jejunum and colon after lambing(P<0.05).In conclusion,reducing DCAD could up-regulate CaBP-D9kexpression level in stomach,proximal intestine and colon,and kept Ca2+concentration for transition goats.The results indicated that Ca2+absorption in the above gastrointestinal tracts was increased and would be the possible mechanism of low DCAD enhancing blood Ca homeostasis in dairy cows during periparturient period.

关 键 词：日粮阴阳离子差 血钙 钙结合蛋白9kDa 围产期山羊 

分 类 号：S827[农业科学—畜牧学]