Pasture Botanical Changes and Steer Gains on Continuously Stocked Hay-Type and Grazing-Tolerant Lucerne Cultivars at Three Grazing Pressures

Alfagraze (grazing-tolerant) and Apollo (hay-type) lucerne (Medicago sativa L.) cultivars were stocked continuously with beef steers at 3 grazing pressures (GP) for 3 years In central Georgia, USA. Lucerne stands declined at the highest GP, Apollo stand density being only 23% of that of Alfagraze in grass-free areas at the end of 3 years. Rapid encroachment by volunteer bermudagrass (Cynodon dactylon (L.) Pers,) at high GP resulted in greater stand loss in Apollo than Alfagraze. Steer average daily'gain on both cultivars declined from 0.95 kg at low GP to 0.76 kg at medium GP with a further decline at high GP to 0.57 kg for Apollo but not for Alfagraze. Gain/ha of both cultivars averaged 296, 331 and 420 kg at low, medium and high GP, respectively, The superior persistence of Alfagraze at continuous high GP, even in competition with grass, indicates its usefulness as a superior pasture legume.