Comparison of Virginia wildrye, annual ryegrass, and wheat for weaned beef steers grazing and confinement feeding

Abstract

Virginia wildrye (Elymus virginicus L.; VWR) was compared with Marshall annual ryegrass (Lolium multiflorum; ARG) and EK102 wheat (Triticum aestivum; WHT) as pasture and with ARG for confinement feeding. Replicated (n = 3) 2.17-ha pastures were continuously stocked with 4 British crossbred steers (initial BW = 233 ± 28.5 kg) per pasture during spring in 2 yr to evaluate ADG and forage nutritive value. Forage TDN (P = 0.87), NDF treated with amylase and sodium sulfite (P = 0.83), and ADF (P = 0.17) were comparable among species. No CP concentration differences (P = 0.12) were observed in 2015; however, CP concentration of VWR (10.1 ± 0.5) was greater (P = 0.01) than that of WHT (8.7 ± 0.5) in 2016. At d 0, ARG relative feed value concentration (133.8 ± 5.4) was greater (P < 0.05) than that of VWR (111.2 ± 5.4) or WHT (117.7 ± 5.4). At d 28 (P = 0.08) and d 56 (P = 0.56), relative feed value was not different among species. Steer ADG was greater on ARG (1.40 ± 0.05 kg/steer per day) than on WHT (1.20 ± 0.05 kg/steer per day; P < 0.01) or VWR (1.26 ± 0.05 kg/steer per day; P = 0.03). Penned steers had comparable (P = 0.90) daily DMI of ensiled ARG (7.99 ± 0.14 kg/d) and VWR (7.88 ± 0.14 kg/d) in 2015 but more (P < 0.0001) daily DMI of VWR (7.42 ± 0.14 kg/d) than of ARG (6.19 ± 0.14 kg/d) in 2016. Further research is needed to explore forage persistence and economics of VWR for grazing.