Effects Of Different Levels And Proportions Of Branched Chain Amino Acids On Rumen Fermentation Parameters And Microbial Population In Vitro

The aim of this study was to evaluate the effects of different levels and proportions of branched chain amino acids on rumen fermentation parameters and microbial population in vitro. This paper first discussed effects of different supplemental levels of urea and branched chain amino acids on rumen fermentation parameters and microbial population in vitro, and further researched effects of different proportions of branched chain amino acids on rumen fermentation parameters and microbial population in vitro. This study divided into four parts.Partl. Effects of different supplemental levels of urea and branched chain amino acid on rumen fermentation parameters in vitro This study was carried out to investigate the effect of different levels of urea and branched chain amino acid on rumen fermentation parameters in vitro. Urea, leucine(Leu), isoleucine(Ile) and valine(Val) supplementation were0,50,100and200mgN/L respectively in vitro. Culture medium in vitro was sampled to determine fermentation parameters. This study showed that in branched chain amino acid groups, the pH and ammonia nitrogen concentration were decreased significantly (P<0.05); in the Leu and Isoleucine groups, the concentration of MCP production were higher than the MCP concentration in urea group (P<0.05); in Ile group, the concentration of acetate and propionate were higher than other groups (P>0.05); with the nitrogen concentration increasing, the concentration of pH, NH3-N, MCP concentration were increased significantly (P<0.05); the effect of branched chained amino acid on rumen fermentation parameters were better than urea; the effects of nitrogen concentration on MCP concentration were greater than different sources. Part2. Effects of different supplemental levels of urea and branched chained amino acid on rumen microbial population in vitro This study was carried out to investigate the effect of different levels of urea and branched chain amino acid on rumen microbial population in vitro. Urea, leucine(Leu), isoleucine (Ile) and valine(Val) supplementation were0,50,100and200mgN/L respectively in vitro. Culture medium in vitro was sampled to determine the microbial quantity. This study showed that when the supplementation of isoleucine concentration were100and200mgN/L, the total anaerobic fungi quantity were significantly increased compared with0mgN/L (P<0.05); Compared with0mgN/L, the quantity of Ruminococcus species were significantly increased in the groups of valine,100and200mgN/L of leucine and200mgN/L of urea (P<0.05), the quantity of Fibrobacter succinogenes were significantly increased in the groups of200mgN/L of valine,50and100mgN/L of urea; in every level of leucine and isoleucine, the quantity of Fibrobacter succinogenes were significantly decreased (P<0.05); when the nitrogen concentration were50and100mgN/L, in the urea groups, the quantity of structural carbohydrates degrading bacteria(Ruminococcus species and Fibrobacter succinogenes) were higher than in branched chain amino acid groups; in50mgN/L of leucine and200mgN/L of isoleucine groups, the quantity of non-structure carbohydrates degradaing bacteria (Butyrivibrio fibrisolvens) were significantly increased (P<0.05); in every level of valine and leucine group, the quantity of non-structure carbohydrates degradaing bacteria(Ruminobacter amylophilus and Streptococcus bovis) were significantly increased (P<0.05); compared with0mgN/L, in100and200mgN/L of the urea groups, the quantity of non-structure carbohydrates degradaing bacteria(Butyrivibrio fibrisolvens and Streptococcus bovis) were significantly decreased (P<0.05).Part3. Effects of different proportions of branched chain amino acids on rumen fermentation parameters and microbial population in vitro This study was carried out to investigate the effect of different proportions of branched chain amino acid(leucinc, isoleucine and valine) on rumen fermentation parameters and microbial population in vitro. The proportions of branched chain amino acids as follows:(Val:Leu:Ile=2:2:2(A),2:3:1(B),1:3:2(C),3:1:2(D),2:1:3(E),1:2:3(F),3:2:1(G) the total nitrogen content was200mgN/L). Culture medium in vitro was sampled to rumen fermentation parameters and the microbial quantity. Results from this study showed that the different proportions of branched chain amino acids had no effect on gas production and ammonia nitrogen concentration (P>0.05), when the Val:Leu:Ile was2:3:1, protozoon protein and the concentration of MCP were significantly decreased (P<0.05); Raise the proportion of the leucine, decreasing the proportion of isoleucine,the quantity of starch and protein degradation bacteria(Butyrivibrio fibrisolvens and Streptococcus bovis) were increased.Part4. Effects of different proportions of branched chain amino acids on the dynamic rumen fermentation parameters and microbial population in vitroThe proportions of branched chain amino acids as follows:(Val:Leu:Ile=2:2:2(A),2:1:3(B),2:3:1(C)), studied the fermentation parameters and the microbial quantity of0,3,6,12and24h in vitro. Culture medium in vitro was sampled to the rumen fermentation parameters and the microbial quantity. Results from this study showed that when24h fermentation, in group A and C, the gas production were significantly higher than in group B (P<0.05); when3h, the pH was the lowest, when to12h, which was significantly decreased in group A(P<0.05), at the other times, the pH value no significant difference (P>0.05) in these groups; at3h, the ammonia concentration was significantly lower than the other two groups (P<0.05), when up to6h, in group C, ammonia concentration was the lowest (P<0.05), in the24h, ammonia concentration was the lowest in group B(P>0.05); with the extension of the fermentation time, protozoa, protein and bacterial protein were all increased, at3h,6h and12h of fermentation, the protozoan protein in group C was significantly higher than the other two groups (P<0.05), while at3h of fermentation, the bacterial protein in B group was significantly higher than the other two groups (P<0.05), at the12h of fermentation, bacterial protein was highest in group C (P<0.05), the concentration of the total microbial protein in group C was significantly higher than group A at3h fermentation(P<0.05), at12h the microbial protein concentration in group C was significantly higher than the other two groups (P<0.05), other times they were no significant difference (P>0.05); the quantity of Streptococcus bovis was significantly higher than the other two groups in group C at6h(P<0.05), at24h, which quantity was the highest in group A (P<0.05); different proportions of branched chain amino acids had no effect on Ruminobacter amylophilus (P>0.05).The results show that:the effects of branched chained amino acid on rumen fermentation parameters were better than urea, leucine was the most favorable to synthesis MCP, the effect of nitrogen concentration on rumen MCP was greater than different sources; when the nitrogen concentration were50and100mgN/L, in the urea groups, the quantity of structural carbohydrates degrading bacteria were higher than in branched chain amino acid groups; in branched chain amino acid group, the quantity of non-structural carbohydrates degrading bacteria were higher than urea groups; when the Val:Leu:Ile was2:3:1,which was improved the MCP concentration; different proportions of branched amino acids had timeliness effects on the non-structural carbohydrates degrading bacteria.