Forage nutritive value of stock‐piled cicer milkvetch for late‐season grazing

Abstract

AbstractAchieving high forage production combined with adequate forage nutritive value on Intermountain western U.S. grazing lands during the fall and early winter can be difficult. Crude protein (CP) and neutral detergent fiber (NDF) of cicer milkvetch (Astragalus cicer L.) were characterized relative to alfalfa (Medicago sativa L.), and crested wheatgrass [Agropyron cristatum (L.) Gaertn.]. Forage was harvested monthly September–December from season long stockpiled growth (full‐season), stockpiled regrowth following a June defoliation (mid‐season), and stockpiled regrowth following an August defoliation (late‐season). Crude protein of cicer milkvetch ranged from 11.9 to 9.2%, 20.5 to 14.3%, and 24.6 to 15.9%, in the full‐, mid‐, and late‐season stockpiled strategies, respectively. Overall, cicer milkvetch CP was equal to alfalfa CP and 5.7 percentage points greater than crested wheatgrass CP across all harvest dates of the three stockpiling scenarios. Furthermore, cicer milkvetch NDF was less (more favorable) than both alfalfa and crested wheatgrass, ranging from 46.4 to 59.6%, 23.0 to 37.4%, and 26.2 to 33.7%, in the full‐, mid‐, and late‐season stockpiled strategies, respectively. The high CP and superior NDF of cicer milkvetch indicate it has unrealized potential for improving forage nutritive value of grazing lands in the western United States, particularly in the late fall to early winter.