Grazing Beef Steers on Native-Warm Season Grasses: Implications for Beef and Biomass Production

Native warm-season grasses (NWSGs) have demonstrated potential to reduce summer forage variability in the region, and there has been growing interest in the use of NWSGs as a lignocellulosic biomass crop. The objectives of this research were to determine if there was a difference in beef yield and net returns for grazing beef steers on three NWSGs during the summer months, and to determine the breakeven price of biomass a beef cattle producer would need to receive to use a dual-purpose grazing and biomass production system. Beef steers grazed switchgrass (Panicum virgatum L.) (SG), a big bluestem (Andropogon gerardii) and indiangrass (Sorghastrum nutans) mixture (BBIG), and eastern gamagrass (Tripsacum dactyloides) (EG) at two locations in Tennessee from 2010-2012. The dual-purpose grazing occurred for the first 30-days of summer and the remaining biomass was harvested post-dormancy, and full-season grazing occurred for 90-days of summer. Budgets were developed for each NWSG to calculated net returns, and mixed models were estimated to determine differences in beef yield and net returns across each NWSG and location. Expected yield and net returns to full-season grazing were not difference across the three NWSGs at AP. However, expected yield and net returns to full-season grazing were higher for BBIG than SG at HR.A profit-maximizing, risk neutral individual would increase net returns by grazing any of the NWSGs over marketing calves at weaning. The breakeven biomass prices ranged between $37-123 Mg−1 depending on the NWSG and location.