Influence of slice baling on feeding value of alfalfa hay in receiving and finishing diets for feedlot cattle.

摘要

Three studies were conducted to evaluate the feeding value of slice alfalfa hay in feedlot diets. In Exp. 1, 108 steer calves (183.1 pl 1.2 kg initial BW; 6 pens/treatment) were used in a completely randomized design to evaluate the effect of baling method on performance and morbidity of newly received calves. The study lasted 28 d. Treatments consisted of a 65% concentrate receiving diet containing 1) ground or 2) slice alfalfa hay. Steer calves were fed daily at 0800 h. Animals also received long-stem sudangrass hay the first 7 d. Steers were weighed on d 0, 16, and 28. Feed, sudangrass hay, or feed plus sudangrass hay intakes were not affected (P > 0.25) by treatment. Conversely, ADG from d 0 to 16 was greater (P < 0.001) for slice than ground (1.27 vs. 0.81 pl 0.067 kg/d, respectively) and from d 0 to 28 (1.23 vs. 0.91 pl 0.042 kg/d, respectively). In addition, G:F was greater (P < 0.001) for slice than ground hay from d 0 to 16 (0.39 vs. 0.25 pl 0.021), and from d 0 to 28 (0.31 vs. 0.24 pl 0.013 for slice and ground, respectively). Moreover, morbidity (40.5 pl 3.9%; P = 0.20) and retreatment rates (30.7 pl 7.5%; P = 0.14) were similar for slice and ground. In Exp. 2, 176 crossbred steers (393.9 pl 10.8 kg initial BW) were used in an 84-d feeding experiment (4 pens/treatment) in a randomized complete block experimental design with a 2 x 2 factorial arrangement of treatments to evaluate effects of alfalfa baling method (ground or slice) and forage level (8 or 14%) on growth performance. Experimental diets were based on steam-flaked corn. Daily BW gain was greater (P = 0.10) for steers consuming ground compared with the slice hay diet. A baling method x forage level interaction (P = 0.07) was observed for DMI. Baling method did not (P = 0.98) influence DMI with 8% roughage level. But with 14% roughage, DMI was greater (P = 0.02) for steers consuming ground hay than the slice diet. The G:F ratio was affected (P = 0.03) only by forage level (0.194 vs. 0.182 pl 0.003 for 8 and 14% roughage, respectively). In Exp. 3, 4 ruminally cannulated mixed-breed steers were used in a 4 x 4 Latin square design to evaluate effects on digestive function. No baling method effects (P >= 0.16) were detected for DM, OM, CP, or NDF intakes or DM, OM, and NDF total tract digestibility. Digestibility of NDF and OM were greater (P <= 0.08) for diets which contained 14% forage compared with diets that contained 8% forage. Slice baling improved alfalfa hay feeding value for feedlot receiving cattle. However, no major effects of slice baling alfalfa on finishing performance and digestion were observed.