Abstract: Three crossbred wethers fitted with permanent rumen fistula were chosen to measure the effect of different processed diets on parameters of the concentration of volatile fatty acid in sheep rumen. A 3×3 Latin square experiment design was adopted and the sheep were allotted in one of three diet-treatments, which were complete diet pellet, ground concentrate and cut roughage, and unground concentrate and cut roughage. The results showed that the concentration of TVFA of sheep fed unground concentrate and cut roughage was significantly higher than that of sheep fed complete diet pellet(P＜0.05). The molar ratio of propionate of sheep fed ground concentrate and cut roughage as well as unground concentrate and cut roughage were higher than that of sheep fed complete diet pellet(P＜0.05,P＜0.01),but the molar ratio of (valerate and isovalerate) was significantly lower(P＜0.01),and acetate/propionate was lower than that of sheep fed complete diet pellet significantly(P＜0.05,P＜0.01). It suggested that the diets type of ground concentrate and cut roughage or unground concentrate and cut roughage could improve the type of fermenting in sheep.

Key words: processed; sheep; rumen; volatile fatty acid