The Economics of Grazing Beef and Dairy Cattle on Native Warm-Season Grasses in Tennessee

Two separate studies focusing on the economics and animal performance of grazing native warm-season grasses (NWSGs) are presented in this thesis. In the first study, the first objective was to determine if there was a difference in net returns to full-season grazing of beef steers on switchgrass (SG), big bluestem and indiangrass (BBIG), and eastern gamagrass (EG). The second objective was to determine the price of biomass a producer would need to receive to breakeven between full-season grazing beef steers and early-season grazing with a biomass harvest (i.e., a dual purpose grazing and biomass production system) for SG, BBIG, and EG. Mixed models were used to evaluate differences in expected beef yield and net returns from full- season grazing across the NWSGs for the first objective. Mixed models were also used to evaluate differences in expected beef yield, net returns, biomass yield, and the breakeven price of biomass from early-season grazing across the NWSGs for the second objective. Results from the first study indicate the profitability of grazing the NSWGs depends on the location, but on average steers grazing SG had the highest expected net returns to full-season grazing. Additionally, SG had the lowest expected breakeven price of biomass.

In the second study, the objective was to determine the cost of grazing SG and BBIG, with and without legumes, in bred dairy heifer development and compare the cost of grazing to the cost of using traditional feedstuffs. Mixed models were used to evaluate differences in expected cost per animal unit day (AUD) and expected average daily gain (ADG) across the NWSG treatments. The ADG for the Holstein heifers grazing NWSGs was used to design feed rations to obtain the same ADG over the same number of days. The cost day^-1 [cost per day] of using these rations was calculated with different daily yardage fees and compared the cost AUD^-1 [cost per animal unit day] of grazing bred dairy heifers on NWSGs. Results from the second study indicate SG to have the lowest expected cost AUD^-1 of developing bred dairy heifers of all the NWSGs and feed rations.