[The effect of unprocessed beech sawdust on rumen fermentation in rams and goats].

In a trial with wethers and goats the effect of non-conditioned beech sawdust (NBS) was studied as exerted on ammonia concentration, total VFA concentration, molar VFA percentage, energetic yield of VFA production, on the acetate : propionate ratio in rumen contents, and on urea concentration in blood. NBS was used in diets to replace bulk forage. The proportions of NBS in diets were 0, 5, 10, 15 and 20% (replacing hay). The results of the trials show that the administration of the different diets did not affect the concentration of ammonia and total VFA in the rumen content and the concentration of urea in blood. Goats showed an insignificant increase in the molar percentage of acetic acid, a decrease in the molar percentage of propionic acid and n-butyric acid when diets with gradated NBS proportions were administered, as well as an insignificant increase in the acetate : propionate ratio and a decrease in the energetic yield of VFA. In wethers the values of propionic and n-butyric acid were highly variable, which implied variation also in the acetate : propionate ration or in the energetic yield of VFA in the administration of different diets.