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

Abstract

<h2>ABSTRACT</h2> Virginia wildrye (<i>Elymus virginicus</i> L.; VWR) was compared with Marshall annual ryegrass (<i>Lolium multiflorum</i>; ARG) and EK102 wheat (<i>Triticum aestivum</i>; 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 (<i>P</i> = 0.87), NDF treated with amylase and sodium sulfite (<i>P</i> = 0.83), and ADF (<i>P</i> = 0.17) were comparable among species. No CP concentration differences (<i>P</i> = 0.12) were observed in 2015; however, CP concentration of VWR (10.1 ± 0.5) was greater (<i>P</i> = 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 (<i>P</i> < 0.05) than that of VWR (111.2 ± 5.4) or WHT (117.7 ± 5.4). At d 28 (<i>P</i> = 0.08) and d 56 (<i>P</i> = 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; <i>P</i> < 0.01) or VWR (1.26±0.05 kg/steer per day; <i>P</i> = 0.03). Penned steers had comparable (<i>P</i> = 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 (<i>P</i> < 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.