Steer performance and pasture productivity of a tall fescue-bermudagrass system compared with yellow bluestem and Coastal panicgrass1

Year-round grazing in animal production systems has potential in the mid-Atlantic United States. Tall fescue [Lolium arundinaceum (Schreb.) S. J. Darbysh.] is generally the cool-season perennial and bermudagrass [Cynodon dactylon (L.) Pers.] is the warm-season perennial in these systems. This study evaluated yellow bluestem (Bothriochloa ischemum L.; YBS) and Coastal panicgrass (Panicum amarum var. amarulum; CPG) for their quality and productivity with a tall fescue-bermudagrass system (BGS) as a control. Steer ADG (kg/d) was less (P = 0.05) in the BGS (0.66) than the mean of 0.77 from YBS (0.68) and CPG (0.86), which differed (P = 0.02). Steer ADG (kg/d) in spring (0.95) was greater  (P < 0.01) than summer (0.53), but pasture species interacted with season (P = 0.02). The ADG of CPG was stable across season (from 0.97 to 0.76 kg/d), whereas BGS or YBS declined from 0.97 and 0.92, respectively, to 0.37 and 0.49 kg/d. Dietary in vitro true OM disappearance was similar among species (P = 0.29) and seasons (P = 0.62), averaging 803 g/kg; however, DMI (kg/d per 100 kg of BW) was least (P = 0.05) from the BGS (2.64) compared with YBS (2.97) and CPG (3.40) (P = 0.09). The BGS was stocked greater (P < 0.01) at 12.3 compared with 6.2 and 4.9 steers/ha for YBS and CPG, respectively. Adjusting for days tall fescue was grazed (23%) still favored the BGS. No difference in steer gain (P = 0.95) and effective feed units (P = 0.54) occurred between YBS and CPG (473 and 2,754 kg/ha).