Effect Of Forage To Concentrate Ration On Rumen Anaerobic Bacterial, Volatile Fatty Acids And Blood Indexes In Dairy Cows

Different forage to concentrate ration has a significant impact on production and health of cow,high-forage diet can result in nutrition metabolism disease and reduce production frequently.Five healthy cows(502±25㎏) during the dry period were used to study the effects of forage to concentrate ration on rumen anaerobic bacterial and volatile fatty acids,some blood indexes. Cows were fed continuously in nine periods and experiment with 30 d each periods except last period that only keeping 3 d.The main ingredients were corn,wheat bran,soybean meal,pachyrhizus vine,corn silage and so on.Dietary forage to concentrate ration were 30:70, 35:65, 40:60, 45:55, 50:50, 55:45,60:40, 70:30, 100:0 concentration respectively.The indexes of rumen pH,VFA(acetate,butyrate and butyric acid ) and the concentration of serum VFA,lipide(TG,CHO,HDL,LDL),Na+,K+,Cl-,HCO3- and free fatty acids were tested. We separated 6 strains anaerobic bacterial from rumen fluide ,analysed 16SrDNA sequence and phylogenic tree construction. The result indicate that:1 Rumen pH was down gradually with the increase of forage to concentrate ration and tended to be the lowest in 100:0 concentration(P<0.05). Serum acetate were different lower (P<0.05) in 50:50 compared with 30:70, 35:65 and 100:0 concentration. Serum propionate and butyrate were no significant different(P>0.05). No relationships were observed between rumen acetate, butyrate and acetate, butyrate in serum(P>0.05), while the relationships between rumen propionate and serum propionate reached extremely significant(P<0.01).2 The serum content of TG was up gradually with the increase of Forage to concentrate ration and tended to be the highest in 100:0(P<0.05) compared with 30:70 concentration.HDL and CHO were significantly higher(P<0.05) in 55:45 compared with 30:70 concentration,others were no significantly different(P>0.05).No significant different(P>0.05) were observed in CHO concentration.The serum content of Lauric acid and Palmitic acid in 55:45 concentration were significantly higher(P<0.05) than that in 30:70. Linoleic acid and nutmeg acid in 55:45 concentration were significantly lower(P<0.05) than that in 30:70,35:65,40:60.Oleic acid and Myristic acid concentration were no significantly different(P>0.05).The serum content of Stearic acid in 55:45 concentration were significantly higher(P<0.05) than that in 30:70,60:40,70:30,100:0.The serum content of saturated fatty acid increased first and then gradually decreased but the content of unsaturated fatty acid was opposite with the increase of Forage to concentrate ration.3 The serum content of Na+ was up gradually with the increase of dietary forage to concentrate ration and no significantly different in every group(P>0.05). The serum content of K+, Cl-, TCO2 decreased first and then gradually increased, there is no siginficant difference in serum concent of K+ among every group. The serum content of Cl- in 100:0 were significantly higher than that in 40:60,45:55,50:50(P<0.05), serum TCO2 in 55:45 concentration were significantly lower than that in 30:70,35:65,40:60,45:50,50:50(P<0.05). The serum content of HCO3- increased first and then gradually decreased after 55:45, but there is no siginficant difference in serum concent of HCO3- after 55:45 group(P>0.05).4 The content of rumen bacterial which produce lactic acid was up gradually with the increase of dietary forage to concentrate ration and tended to be the highest in 100:0(P<0.05) compared with other groups. A 1.5Kb of 16SrDNA fragment amplified through general PCR with the template of bacterium total DNA, and bacteria 16SrDNA universal primers, was ligated into PMD-18-T vector which is classic cloning vector for PCR products, and then was taken to transform chemically competent cell of E.coli DH5α.Restriction enzyme analysis of the transformants, mediated by HindⅢand EcoRⅠ.The BLAST of the 1540～1615 by of 16SrDNA sequence obtained by DNA sequencing, with all 16SrDNA sequences in GenBank indicated that the bacterium 8502,9101,1501,4101,5101,6101 belong to Streptococcus ,Halomonas, Enterococcus,Acinetobacter,Enterobacter. The phylogenic tree of the field bacterium 8502,9101,1501,4101,5101,6101 which were generated by MEGA4.0 software,basing on 16SrDNA full-length sequence,showed that it is most close to Streptococcus bovis strain JB1,Streptococcus bovis strain B315,Halomonas sp. F22157,Enterococcus faecalis strain SL5,Acinetobacter sp. TCCC11051,Enterobacter sp. J11 respectively.5 Based on the result,the conclusion is differents diet forage to concentrate ration have notable effects on rumen pH, VFA and propionate in serum, high forage to concentrate ration increase the concentration of serum lipid and saturated fatty acid,decrease the concentration of un saturated fatty acids, the content of rumen bacterial which produce lactic acid was up gradually with the increase of forage to concentrate ration, the cow obtained relatively tolerance and established stable rumen ecosystem with the increase of forage to concentrate ration.The best production was obtained in 55:45 concentration of the dairy cow,high forage to conentrate ration can result in nutrion and metabolize disease of the cow,such as rumen acidosis,ketosis in dairy cows ,fatty liver syndrome and so on.So the appropriate forage to concentrate ration is very important in the process of cattle breeding.