The effect of thickness of steam-rolled barley on its utilization by beef cattle

Abstract

All-concentrate diets consisting of thin-, medium- or coarse-rolled barley or whole barley were fed to 24 Hereford steers and 24 Hereford bulls. Digestibility trials and chewing studies were conducted on each of the diets. Cattle fed medium-rolled barley gained faster (P < 0.05) (1.62 kg d−1) than those fed thin-rolled (1.49 kg d−1) or whole barley (1.38 kg d−1), and cattle fed coarse-rolled barley gained faster (P < 0.05) (1.53 kg d−1) than those fed whole barley. The average daily gain was similar in cattle fed thin-rolled and whole barley. Feed intake was lower from week 2 to week 8 in cattle fed the thin- and medium-rolled barley diets than in those fed the coarse-rolled and whole-barley diets. Gain-to-feed ratio decreased as the thickness of the roll increased and was lowest in cattle fed whole barley. Energy, protein and starch digestibilities declined with thickness of roll and were lowest for the whole-barley diets. Ruminating time and the time ruminating per kilogram of feed increased as the thickness of the roll increased; rumination time was longest on the whole-barley diet. Key words: Beef cattle, barley, rolling, processing, rumination, digestibility