畜牧兽医学报 ›› 2014, Vol. 45 ›› Issue (9): 1432-1439.doi: 10.11843/j.issn.0366-6964.2014.09.008

• 动物营养 • 上一篇    下一篇

真胃灌注葡萄糖对泌乳奶山羊乳脂合成的影响

张雅彬#,林雪彦#,闫振贵,侯秋玲,师科荣,王中华*   

  1. (山东农业大学动物科技学院,泰安 271018)
  • 收稿日期:2013-12-27 出版日期:2014-09-23 发布日期:2014-09-23
  • 通讯作者: 王中华,博士生导师,教授,E-mail:zhwang@sdau.edu.cn
  • 作者简介:张雅彬(1986-),女,河北石家庄人,硕士,主要从事动物营养与饲料研究,E-mail:zhangyabin44@163.com;林雪彦(1971-),女,山东烟台人,教授,主要从事反刍动物营养与生理研究,E-mail:xueyanlin2005@163.com。二者为共同第一作者
  • 基金资助:

    国家现代农业(奶业)产业技术体系建设专项资金(CARS-37);山东省牛产业体系(SDAIT-12-01-06)

Effects of Abomasal Glucose Infusion on Milk Fat Synthesis in Lactating Goats

ZHANG Ya-bin#,LIN Xue-yan#,YAN Zhen-gui,HOU Qiu-ling,SHI Ke-rong,WANG Zhong-hua*   

  1. (College of Animal Science and Technology,Shandong Agricultural University,Tai’an 271018,China)
  • Received:2013-12-27 Online:2014-09-23 Published:2014-09-23

摘要:

 旨在研究血糖/胰岛素水平升高是否是高精料日粮抑制乳脂合成的途径,及其抑制的机制。采用4只泌乳早期崂山奶山羊,安装真胃插管和颈动脉插管。2×2有重复交叉试验设计,2个试验处理为真胃灌注生理盐水或200 g•d-1葡萄糖。2期试验,每期8 d,2期之间间隔14 d。使用RT-PCR检测乳脂合成相关酶的mRNA表达量。结果表明,真胃灌注葡萄糖显著提高了血糖水平(P<0.05),血浆胰岛素水平有升高趋势(P=0.06)。葡萄糖灌注提高了产奶量(P<0.05),降低了乳脂率和乳脂量(P<0.05)。乳脂中,C18∶0和C9C18∶1的产量显著降低(P<0.05),从头合成的脂肪酸(C4~C14)及血液吸收和从头合成双重来源脂肪酸(C16)的产量无显著变化(P>0.05)。真胃灌注葡萄糖对乙酰辅酶A羧化酶、脂肪合成酶、脂蛋白酯酶、脂肪酸结合蛋白、磷酸甘油酰基转移酶、脂肪酸脱饱和酶等乳脂合成酶和脂肪酸转运蛋白基因的表达无显著影响。结论:真胃灌注葡萄糖主要通过减少血液来源脂肪酸含量来降低乳脂产量;其对乳脂合成相关酶及蛋白基因表达无影响,对乳脂合成的调控发生在转录后。

Abstract:

The aims of the present study were to investigate if high concentrate diets with high concentration blood glucose and insulin depress milk fat synthesis and the underlying mechanism.4 Laoshan dairy goats in early lactation fitted with abomasal and jugular artery catheters were used in a repeated 2×2 crossover experiment.Treatments were abomasal infusion of saline or 200 g•d-1 glucose.The experiment was consisted of two periods.Each period lasted 8 d and there was a 14 d interval between the two periods.RT-PCR was used to detect the mRNA expression of ACC,FAS,LPL,H-FABP,GPAT and SCD.The results indicated that glucose infusion elevated blood glucose (P<0.05) and tended to elevated plasma insulin (P=0.06).Glucose infusion increased milk yield,decreased both milk fat yield and milk fat percentage (P<0.05).Analysis of fatty acid profile of milk fat reveled that glucose infusion decreased the yield of C18∶0 and c9C18∶1 (P<0.05) but had no significant effect on the yields of those de novo synthesized fatty acids (C4-C14) and those dual source fatty acids that may be preformed or de novo synthsized (C16).Glucose infusion had no significant effects on the mRNA experssion of acetyl coenzyme A carboxylase,fatty acid synthetase,lipoprotein lipase,fatty acid bonding protein,glycerol-3-phosphate acyltransferase,stearoyl CoA desaturase and fatty acid transfer protein.It was concluded that abomasal glucose infusion decreased milk fat synthesis mainly by decreasing the amount of pre-formed fatty acids used for milk fat synthesis,had no significant effect on the expression of genes related to milk fat synthesis.The regulation of abomasal glucose infusion on milk fat synthesis occurred after transcription.

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