安格斯妊娠母牛异食行为的营养代谢异常及其与肠道菌群相关性研究

牛异食行为（PICA）是以舔食、啃咬一些无营养价值异物为特征的一种异常行为，大多研究认为，PICA是因某些营养素紊乱和生活环境受限所致。业已证明，肠道菌群与宿主营养代谢关系密切，肠道菌群-肠-脑（micro-biota-gut-brain，MGB）轴与动物行为之间的相关性研究日益被揭示。但PICA牛的营养代谢物变化与其肠道菌群组成和结构变化关系缺乏研究。本研究拟对PICA母牛的肠道菌群组成结构变化与无PICA临床症状的健康牛进行分析比较，以期探明肠道菌群变化与PICA的关系。在针对某集约化安格斯肉牛繁育场PICA牛临床调查基础上，试验选取年龄相同、体重相近、同一舍饲条件下正常妊娠母牛和典型异食行为的妊娠母牛各10头，分为对照组（Ctrl）和异食组（PICA），采集血液和毛发样本对其矿物质元素、脂溶性维生素（VA、VD、VE）、17种游离氨基酸和血清蛋白质进行检测比较，同时采集粪便，分析两组牛的肠道菌群组成结构。结果发现，与Ctrl组相比，PICA组血清中异亮氨酸（Iso）和苯丙氨酸（Phe）含量显著升高（P<0.05）；虽然PICA组的肠道菌群组成结构的α-多样性和β-多样性与Ctrl组相比，均无显著差异（P>0.05），但其中，颤螺菌属（Oscillospira）和CF231相对丰度显著降低（P<0.05）。Pearson相关分析发现，Iso与CF231相对丰度呈显著负相关（P<0.05），Phe与Tenericutes呈显著负相关（P<0.05）。结果提示，肉牛血清中Iso和Phe的改变以及肠道菌群中颤螺菌属（Oscillospira）和CF231相对丰度的变化可能与安格斯肉牛异食行为的产生密切相关。本研究为通过调控肠道菌群治疗PICA提供了一种可能性。

The Relationship between the Malnutritional Metabolism and Gut Microbiota Changes in Pregnant Angus Beef Cows with PICA

PICA behavior of cattle refers to an abnormal behavior characterized by licking and gnawing some foreign matters without nutritional value,which is often considered to be caused by some nutrients disorders and living environmental confinement.It has been proven that a strong association between gut microbiota and host nutritional metabolism is existed.The link between gut microbiota-gut-brain axis(MGB)and the animal behavior is being revealed.However,there is a lack of enough investigation on the relationship between the occurrence of PICA and the changes of gut microbiota in cattle.In this paper the gut microbiota was compared between PICA cows and the normal ones in order to reveal the possible correlation between gut microbiota and PICA behavior.After the clinical survey for PICA cows in an Angus cow breading farm,10 healthy Angus pregnant cows as control group(Ctrl)and their 10 counterparts with typical PICA behavior as PICA group(PICA)were chosen.Blood and hair samples were collected to measure the minerals,fat-soluble vitamins(VA,VD,VE),and 17 free amino acids and total serum proteins.Feces samples were collected and the composition and the structure of gut microbiota were analyzed and compared.The results showed that the serum content of Iso and Phe in PICA cows were significantly higher than those in the Ctrl group(P<0.05).Though theα-diversity andβ-diversity of gut microbiota in PICA cows were not significantly different from those in the Ctrl group(P>0.05),the relative abundance of Oscillospira and CF231 were significantly lowered than those in the Ctrl groups(P<0.05)。Pearson correlation analysis showed that there was a significant negative correlation between Iso content and the relative abundance of CF231,as well as Phe and Tenericutes(P<0.05).The results suggest that the changes of Iso and Phe contents in the serum and the changes of Oscillospira and CF231 relative abundance in gut microbiota could be associated with the generation of PICA behavior in Angus cows,which provides a possibility for developing a therapeutic way to treat PICA via gut microbiota manipulation.