Forage Potential of Kura Clover and Birdsfoot Trefoil when Grazed by Sheep

Abstract Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that has not been adequately evaluated in the USA under grazing. Our objective was to compare kura clover and birdsfoot trefoil (Lotus corniculatus L.) persistence and productivity when seeded in monoculture and in a binary mixture and grazed by lambs. A controlled, high herbage allowance (mean of 7.4% of lamb body weight in forage dry matter per day) was applied for 4 yr to pastures on a Waukegan silt loam (fine‐silty over sandy, mixed, mesic Typic Hapludoll). Initial seeded legume composition of monocultures was >95%, while the composition of the kura clover‐birdsfoot trefoil mixture was initially 10 and 90%, respectively. By the fourth year of grazing, the kura clover monoculture and mixture had >99% kura clover, while the birdsfoot trefoil monoculture had only 20% birdsfoot trefoil (80% broadleaf weeds). At the initiation of grazing, kura clover had 20% greater leafiness and higher forage quality than birdsfoot trefoil. Animal days per hectare and liveweight gain per hectare were initially similar for the legume monocultures and mixtures, but by the fourth year were 105% and 86% greater, respectively, for the kura clover dominated mixture and the kura clover monoculture than for the birdsfoot trefoil monoculture. Average daily lamb gain was similar (4‐yr mean of 199 g per lamb) for the treatments each year. Seeding with birdsfoot trefoil did not reduce the incidence of lamb bloat (6%) that occurred on kura clover pastures when kura clover comprised 20% or more of the mixture. Kura clover has potential as a pasture legume in the northern USA because of its excellent persistence, ability to spread, and high forage quality. Additional evaluation of animal performance under lower herbage allowance and on determination of kura clover compatibility with grasses in mixtures is warranted.