LAUSR

Two in vitro trials were carried out to study the effects of supplementing vitamin E (V E ) on rumen fermentation. In Trial I, four levels of V E product (purity 50%), i.e. 0, 15, 30, and 60 mg/kg dry matter (DM) of feed (equivalent to 0, 7.5, 15, 30 IU V E /kg DM) were supplemented to a typical feed mixture, respectively, as experi - mental treatments. The gas test technique of Menke et al. (1979) was used to measure gas and volatile fatty acid (VFA) production. In Trial II, the in vitro incubation technique of Zhao and Lebzien (2000) was used to determine DM disappearance rate and utilizable crude protein (uCP). Four levels of V E , i.e. 0, 7.5, 15, 30 IU/kg DM were sup - plemented to the same feed mixture as in Trial I, respectively, as experimental treatments. The results showed that supplementing V increased total gas production ( P < 0.01) and tended to increase methane (CH 4 ) production (P = 0.087). Supplementing V also increased total VFA ( P < 0.05) and propionate ( P < 0.05), tended to increase acetate production ( P = 0.084), and significantly increased DM disappearance rate ( P < 0.05) and uCP ( P < 0.01). It