Effect Of Different Materials Coated γ-Aminobutyric Acid On Rumen Fermentation Characteristics In Yanbian Yellow Cattle

This study includes two parts:the first part is the in vitro experiment, the second part is the in vivo metabolism experiment, it was used to study the effect of coated y-aminobutyric acid on rumen microbial fermentation characteristics in Yanbian cattle and its effectiveness. The main research showed as follows:Experiment one:effect of coated GAB A by palmitic acid on rumen microbial fermentation characteristics in vitroThis experiment used multi level-single factor design and in vitro cultured method. Set 5 levels:0 (CON),30,60,90,120 mg,3 replicates per treatment. The results showed that:At 1 and 3 h, acetic acid/propionic acid ratio of 120 mg group was significantly lower than that of the CON (P<0.05), At 6 and 12 h, the VFAs concentration of the experimental group were significantly higher than that of the CON (P<0.05); At 3 and 12 h, gas production of 120 mg group was significantly lower than that of the CON (P<0.05); At 1 and 6 h, the H2 production of 120 mg group was significantly lower than that of the CON (P<0.05); At 3 h, the CH4 production of each experimental group was significantly lower than that of the CON (P<0.05); At 6 h, the CH4 production of 90,120 mg group was significantly lower than that of the CON (P<0.05); At 9 and 12 h, the CH4 production of 60,90 and 120 mg group was significantly lower than that of the CON (P<0.05); At 3 and 6 h, the CO2 production of 60 mg group was significantly lower than that of the CON (P<0.05). Based on the results obtained from the present study, it was concluded that: coated GABA by palmitic acid increased the concentration of C2, C3, C4 and TVFA; reduced the total gas production; reduced the production of CO2 and CH4; Overall data indicated that addition of 90 mg is optimal supplemental level under the present in vitro fermentation conditions.Experiment two:effect of coated GABA by palmitic acid-calcium on rumen microbial fermentation characteristics in vitroThis experiment used multi level-single factor design and in vitro cultured method. Set 5 levels:0 (CON),30,60,90,120 mg,3 replicates per treatment. The results showed that:At 1 and 6 h, acetic acid/propionic acid ratio of 60 mg group was significantly lower than that of the CON (P<0.05), At 3,6 and 12 h, the MCP concentration of 120 mg group was significantly higher than that of the CON (P<0.05); At 12 h, the H2, CH4 and CO2 production was significantly lower than that of the CON (P<0.05). Based on the results obtained from the present study, it was concluded that:coated GABA by palmitic acid-calcium decreased the concentration of C2, C3, C4 and TVFA. Coated GABA at level of 90 mg changed acetic acid/ propionic acid model; increased the concentration of MCP; reduced the production of H2, CH4 and CO2; Overall data indicated that addition of 90 mg is optimal supplemental level under the present in vitro fermentation conditions.Experiment three:effect of different materials coated GABA on rumen microbial fermentation characteristics in vitroThis experiment used multi level-single factor design and in vitro cultured method. Set 4 levels:CON, coated GABA by palmitic acid, coated GABA by palmitic acid-calcium and uncoated GABA at level of 120 mg,3 replicates per treatment. The results showed that:At 6 h, acetic acid/propionic acid ratio of group B was significantly higherr than that of the CON (P<0.05), At 12 h, the C3 concentration of the experimental group was significantly higher than that of the CON (P<0.05); At 3 and 12 h, the MCP concentration of group B and C was significantly higher than that of the CON (P<0.05); At 3 h (6 h), gas production of group C(A, B) was significantly higher (lower) than that of the CON (P<0.05); At 1 h, the CH4 production of group B was significantly higher than that of the CON (P<0.05), At 6 h, the CH4 production of group A was significantly higher than that of the CON (P<0.05). Based on the results obtained from the present study, it was concluded that:compared with other experiment group, coated GABA by palmitic acid at level of 120 mg was more conducive to the rumen microbial fermentation in vitro under the present conditions.Experiment four:effect of coated GABA by palmitic acid on rumen microbial fermentation characteristics in vivoThis experiment used 4×4 Latin square design and in vivo metabolism method. Set 4 levels:0,2.3,4.6,6.9 g/kg (DM basis),3 replicates per treatment. The results showed that:at 3 h, the pH of 4.6 and 6.9 g/kg group was significantly lower than that of the CON (P<0.05).; NH3-N concentration of 4.6 and 6.9 g/kg group was higher than that of the CON (P<0.05) at 3 h but lower than that of the CON (P<0.05) at 6 h; At 1 h, the C4 concentration of 4.6 g/kg group was significantly higher than that of the CON (P<0.05), at 3 h, the TVFA and C4 concentration of 4.6 g/kg group was significantly higher than that of the CON (P<0.05), the C2 concentration of 4.6 and 6.9 g/kg group was significantly higher than that of the CON (P<0.05), the acetic acid /propionic acid ratio of 2.3 g/kg group was significantly lower than that of the CON (P<0.05), at 6 h, the C3 concentration of 2.3 g/kg group was significantly lower than that of the CON (P<0.05), the acetic acid/propionic acid ratio of 2.3 and 6.9 g/kg group was significantly higher than that of the CON (P<0.05). Based on the results obtained from the present study, it was concluded that:coated GABA by palmitic acid decreased the pH of feeding 3 h; Increased the NH3-N concentration of feeding 3 h but decreased the NH3-N concentration of feeding 3 h; Increased the concentration of C2, C3, C4, TVFA and the acetic acid/propionic acid ratio(feeding 3 and 6 h).