Effect Of High Concentrate Diet On The Expression Of GPR 41 And GPR 43 In Rumen And Cecum Tissue Of Ruminant

In milk industry,for keeping up with the increasing energy requirement of dairy cows in the early and middle lactation stages and high milk production,high concentrate diet is widely used,but long period of this feeding method will cause subacute ruminal acidosis(SARA)and other metabolic syndrome.In this experiment,Holstein dairy cows were experimental animals,the techniques of gas chromatography,Radioimmunoassay(RIA)and molecular biology were used for figuring out the effect of high concentrate diet on the quantity and composition of the volatile fatty acid(VFA)and fermentation type in rumen,moreover on the expression of GPR 41 and 43 in intestine of ruminant.We also chose the milk goats in the middle lactation stage for the comprehensive regulation test.Two groups were all fed with high concentrate diet with 6:4 concentrate roughage ratio,and the concentrate of the comprehensive regulation group(CC)were palletized and added buffer agent.We wanted to study whether the comprehensive regulation can reduce the negative effect of high concentrate diet on the ruminant and its effect on the expression of GPR 41?43,to improve the method of high concentrate feeding.Experiment 1:Effect of high concentrate diet on VFA and GPR41?43 of rumen in ruminant:Six Holstein dairy cows in the middle lactation stage were chose for the experiment of the effect of high concentrate diet on the volatile fatty acid(VFA),fermentation type and the expression of GPR41?43 in rumen.They were divided into two groups random.One group was high concentrate group(HC)(6:4 concentrate roughage ratio),another was high roughage group(HR)(4:6 concentrate roughage ratio).Rumen fluid was collected through rumen fistula during 0 to 12 hour after feeding,PH of ruminal fluid was detected,VFA was analysed by gas chromatography.Radioimmunoassay(RIA)was used to measure the concentration of inflammatory factor IL-1??IL-6?TNFa in peripheral blood.The technique Real-Time PCR was applied to measure the relative expression of GPR 41 and GPR 43.The result showed:after feeding with high concentrate diet(6:4 concentrate roughage ratio),the amount of acetic acid decreased highly significantly,the percentage of acetic acid and A/P decreased,the percentage of propionic acid increased,and these changes were significant.The mean pH of HC reduced highly significantly,and the time of PH under 5.6 and 6.0 of HC was significantly longer than the time of HR.The concentration of inflammatory factor IL-1??IL-6?TNF? in peripheral blood of HC was higher than the concentration of HR,meanwhile the difference of IL-1? between two groups was highly significant,the difference of IL-6?TNF? was significant.In rumen the relative expression of GPR41?43 of HC was significantly higher than HR,in cecum the relative expression of GPR41?43 of HC was highly significantly higher than HR.Conclusion:feeding the diary cow with high concentrate diet could change the fermentation type of rumen.The subacute ruminal acidosis(SARA)could be induced by long-term feeding high concentrate diet,because it decreased the pH,extended the time of pH under 5.6 more than 3 hours,and rose the concentration of inflammatory factor in peripheral blood.The high concentrate diet could increase the expression of GPR41?43 in rumen and cecum in ruminant.Experiment 2:Effect of comprehensive regulation on VFA and GPR41?43 of rumen in ruminant:Eight milk goats in the middle lactation stage were used for the comprehensive regulation test to study whether the comprehensive regulation can reduce the negative effect of high concentrate diet on VFA,and its effect on the expression of GPR41?43.There were two groups,the comprehensive regulation group(CC)and the high concentrate group(HC),which were all fed with high concentrate diet with 6:4 concentrate roughage ratio,and the concentrate of CC group were palletized and added buffer agent.Rumen fluid was collected through rumen fistula during 0 to 10 hour after feeding,PH of ruminal fluid was detected,VFA was analysed by gas chromatography.Radioimmunoassay(RIA)was used to measure the concentration of inflammatory factor IL-1??IL-6?TNF? in peripheral blood.The technique Real-Time PCR was used to measure the relative expression of GPR 41 and GPR 43.The result showed that:the amount of acetic acid?butyric acid and the total VFA of CC group were extremely significantly higher than HC group.The percentage of acetic acid and A/P increased signicantly too,the percentage of butyric acid decreased significantly.So the comprehensive regulation changed the fermentation type of rumen markedly.After the comprehensive regulation,the pH mean increased highly significantly,the time of pH under 6.0 shortened significantly.The concentration of inflammatory factor IL-1??IL-6?TNFa in peripheral blood of CC was lower than the concentration of HC,meanwhile the difference of IL-1? between two groups was significant,the difference of IL-6?TNF?was highly significant.GPR41?43 expressed in rumen,duodenum,cecum and colon in milk goats.Compared with HC,the CC expressed more GPR41?43 in rumen and duodenum,but expressed less GPR41?43 in cecum and colon.Conclusion:the comprehensive regulation could modulate the fermentation type of rumen notably,increased the pH value of rumen environment,reduced inflammation in the body,so the ruminant could ferment more VFA in a relatively stable rumen acidic environment to achieve high production of milk and meat.So the comprehensive regulation is a good improved method for the mode of the high concentration diet feeding in modern milk industry.