Effects of additions of sodium bicarbonate, salt, Aspergillus oryzae culture extract, niacin, lysine or phenylalanine to ground corn-based supplements on feed intake and digestion by Holstein steers consuming bermudagrass ( Cynodon dactylon) hay

Abstract

Holstein steers were fed bermudagrass ( Cynodon dactylon) hay ad libitum and ground corn-based supplements, to determine if various additives might improve feed intake and/or digestion. Five steers (199 and 260 kg initial and final body weights, respectively) used in the first study (Latin square) were not supplemented (Control) or received 0.75% body weight (BW; dry matter basis) daily of corn in one or two meals (1M and 2M, respectively) or corn once daily with added sodium bicarbonate (0.02% BW, dry matter basis; BUFF) or sodium chloride (0.15% BW, dry matter basis; SALT). Hay organic matter (OM) intake was lower with than without supplementation ( P < 0.05) and lower for SALT than 2M ( P < 0.06; 6.38, 5.85, 5.67, 5.42 and 5.17 kg day −1 for Control, 1M, 2M, BUFF and SALT, respectively). Digestible OM intake was greater ( P < 0.05) with than without supplementation (3.33, 4.08, 4.24, 4.08 and 4.17 kg day −1 for Control, 1M, 2M, BUFF and SALT, respectively). In the second study (Latin square), six steers (156 and 251 kg initial and final BW, respectively) were not supplemented (Control) or received a ground corn-based supplement (approximately 1.0% BW of corn dry matter) alone (Basal) or with culture extract from Aspergillus oryzae (CUEX), niacin (NIA), lysine (LYS) or phenylalanine (PHE). Supplement treatments depressed ( P < 0.05) hay OM intake similarly (4.57, 3.82, 3.73, 3.83, 3.99 and 3.86 kg day −1 for Control, Basal, CUEX, NIA, LYS and PHE, respectively). Digestible OM intake was 2.90, 3.88, 3.87, 3.90, 4.09 and 3.79 kg day −1 (standard error 0.077) for Control, Basal, CUEX, NIA, LYS and PHE, respectively. No additive markedly affected intake or digestion. The long period of corn consumption with added salt apparently tended to elevate digestion but to depress total intake.