Complementary grazing of native pasture and Old World bluestem

Native pasture and Old World bluestems (Bothriochloa spp.) have contrasting herbage production characteristics that suggest potential for incorporation into a complementary forage system. We compared 2 yearling beef production systems consisting of either native pasture (Native) or Old World bluestem combined with native pasture (Old World bluestem-Native) over 5 years. Crossbred steers (initial weight 257 kg) grazed only native pasture in the Native system, but alternated between Old World bluestem and native pastures in the Old World bluestem-Native system. Production system had no effect on the frequency of any plant species in the native pastures (P > 0.16) even though stocking rate in the growing season was increased 31% in the Old World bluestem-Native system. Peak standing crop of Old World bluestem averaged 4640 kg ha(-1) but did not differ between the cultivars 'WW-Iron Master' and 'WW-Spar' (P = 0.16). Individual steer gain was higher in the Native system during the Winter (P < 0.01) and Early Native (P = 0.03) management periods, but was greater in the Old World bluestem-Native system when steers were grazing Old World bluestem in June and July (P < 0.001). Over the entire season, steers in the Native system gained 13.5 kg head(-1) more than steers in the Old World bluestem-Native system. Total livestock production was greater in the Old World bluestem-Native system (77 versus 47 kg ha(-1), P < 0.01). Relative economic returns between the 2 systems were dependent on the marginal value of livestock gain and the relative costs of production for the 2 types of pasture. With average costs for native pasture of $17 ha(-1) and for Old World bluestem pasture of $62.10 ha(-1), the Native system was often more profitable, even though livestock production per ha was much higher with the Old World bluestem-Native system. Lower costs for native pasture and high values of livestock gain favored the Native system.