The effect of forage to concentrate ratio on ruminal parameters in Huanghuai white goat

The objective of this study was to evaluate the effects of forage to concentrate ratio on rumen parameters.Three rumen-fistulated Huanghuai white goats were used in a 3×3 Latin square design.Diets included concentrate,Leymus chinensis,and contained similar concentrate mixtures.with forage to concentrate ratios of 3∶7,4∶6,5∶5 [dry matter(DM) basis],respectively,The samples of rumen content were taken to determine fermentation parameters such as pH,ORP,NH3-N,VFA and MCP at 0,2,4,6,8,10,12 h during the experiment.The results demonstrated that pH and ORP did not differ among treatments(P0.05),while pH declined quadratically as of increased concentrate;concentration of acetic acid and butyric acid in rumen was significantly higher in 3∶7 group than in 4∶6 group and 5∶5 group(P0.05),and concentration of propionic acid in rumen was significantly lower in 3∶7 group than others(P0.05),furthermore VFA did not differ significantly between 4∶6 and 5∶5 treatments(P0.05);nitrogen metabolism did not differ among treatments(P0.05),however concentration of NH3-N and MCP yield in rumen increased with quadratically higher concentrate percentage.Results indicated that forage to concentrate ratios impacts the rumen fermentation,and the diet with concentrate at levels of 40% to 50% is of benefit to performance of Huanghuai white goat.