Abstract
Research has found conflicting results on animal performance and carcass traits associated with the use of forage as the primary feed source for finishing cattle. Consumer interest in forage-fed products has grown and little research has been done comparing performance of forage-fed animals and beef finished on different forages. Spring weaned calves (n=54; 257 ± 2.5 kg; 3/8 Gelbvieh, 3/8 Red Angus, and 1/4 Brahman) were used in the evaluation of three forage systems (S1, S2, and S3) on a 100% forage diet in two consecutive years (June 2009 and 2010). Steers were divided into 9 groups based on initial body weight (d0) and randomly assigned to replicates within system (3 replicates per system). Pastures were rotationally stocked at 1.01 ha/steer. Steers in S1 grazed bermudagrass (45% of area) during summer, and ryegrass (35% of area) and ryegrass sod-seeded into bermudagrass paddocks (20% of area) in winter. Steers in S2 grazed bermudagrass (45% of area) during summer, dallisgrass/clover mix (20% of area) during fall and spring, and ryegrass/cereal rye/clover mix (35% of area) during winter. Those in S3 had access to bermudagrass (20% of area) and sorghum-sudan hybrid/forage soybean during summer (7.5% of area each), dallisgrass/clover mix (20% of area) during fall and spring, and ryegrass/cereal rye/clover mix (45% of area) during winter. Excess forage was cut for hay and fed within system when necessary. Average daily gain (ADG) for summer, winter and for the whole study were not different (P > 0.05) between systems. Animals in Y2 (0.5 kg/d) gained more (P > 0.05) than those in Y1 during summer (0.21 kg/d), but ADG in Y1 (1.5 kg/d) was greater (P > 0.05) than in Y2 (1.3 kg/d) during winter. No significant differences (P > 0.05, Table 3.12) were found in final weights, LM area, KPH, YG, lean color and marbling. Dressing percentage and hot carcass weight were greater (P < 0.05) for S3 than those for S1 and S2 was intermediate. Backfat and PYG was affected by YxS interaction (P < 0.05). Cooking loss and Warner-Bratzler shear force were greater (P < 0.01) for Y1 than for Y2.
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