Snaplage residue as a fiber source for finishing beef cattle under grazing: effects on residue characteristics, cattle behavior and performance, and carcass traits.

Abstract

The snaplage residue presents itself as a potential alternative roughage source in finishing systems, owing to its high fiber concentration which aids in maintaining rumen health. Nevertheless, the performance of animals will hinge on both the allowance and the nutritive value it offers. This study aimed to evaluate different stocking rates of heifers grazing snaplage residue as an exclusive source of fiber on finishing phase performance. The treatments included two stocking rates (SR): i) low stocking rate (LS; 3.5 AU/ha) and ii) high stocking rate (HS; 7.0 AU/ha), which were obtained by modifying the size of the paddocks. Crossbred beef heifers (n = 48; initial body weight = 276 ± 23 kg) were assigned to 16 paddocks (3 heifers/paddock). The concentrate (87% of corn, 3.5% of soybean meal, 3.9% of cottonseed meal, 1.2% of urea, and 4% of mineral; DM basis) was fed ad libitum daily at 0600 hours. Data were analyzed using the MIXED procedure of SAS. There was no SR × time effect (P = 0.88) on residue mass. There was less (P < 0.01) total residue mass for HS than LS, and total mass decreased (P < 0.01) over time. There was no SR × time effect (P ≥ 0.16) for behavior characteristics. There was no difference between HS and LS for average residue intake (P = 0.34; 0.44 vs 0.48 kg/d, respectively), concentrate intake (P = 0.84; 7.72 vs 7.78 kg/d, respectively), and daily gain (ADG; P = 0.94; 0.95 vs 0.95 kg/d, respectively), The HS treatment increased (P < 0.01) gain per area (618 vs 309 kg/ha) compared to LS. No differences between SR were observed for carcass characteristics (P ≥ 0.12). The meat's chemical composition was not different (P ≥ 0.37) between treatments. Overall, the snaplage residue stocking rate did not affect the finishing phase performance of beef heifers, but the greater stocking rate (7.0 AU/ha) increased gain per land area.