Effects of barley grain processing on the site and extent of digestion of beef feedlot finishing diets.

摘要: Effects of extent barley rolling on chewing activities, ruminal fermentation, and site digestion were evaluated for feedlot finishing cattle diets in a 4 x Latin square design. Four Jersey steers (452 kg), cannulated the rumen duodenum, used. Barley grain was temper-rolled to four extents: coarse, medium, medium-flat, flat, which expressed as processing index (PI, volume weight after percentage its before processing, DM basis) equivalent 82, 75, 70, 65%, respectively. Diets consisted 9.7% silage, 86% barley, 4.3% other ingredients (DM basis). Steers offered ad libitum access total mixed ration once daily. Dry matter intake not affected (P > 0.15) by PI barley. Digestibility OM tract numerically lower = 0.13) fed coarsely rolled than more extensively processed starch linearly increased 0.02) with but NDF 0.15). CP did differ tended 0.08) increase Flow microbial nitrogen duodenum approximately one-third (linear effect, P 0.06) further Increased decrease rumination time without affecting eating time. These results indicate that optimal degree corresponded 75% or lower. Coarsely is recommended because it resulted lowest digestibility protein synthesis. Processing attain less marginal improvements feed digestion, decreased, could lead problems associated acidosis if lower-fiber are