INFLUENCE OF ENDOPHYTE, ALFALFA, AND GRAZING PRESSURE ON STEER PERFORMANCE AND PLANT PERSISTENCE OF JESUP TALL FESCUE

Endophyte [Neotyphodium coenophialum (Morgan-Jones & W. Gams) Glenn, B acon, Price & Hanlin] toxicosis of cattle on tall fescue (Festuca arun dinacea Schreb.) pasture can be offset by using an endophyte-free (E-) cultivar, adding a legume, or possibly by increasing grazing pressure . Release of a more persistent E- tall fescue, 'Jesup', and 'Alfagraze ' grazing-tolerant alfalfa (Medicago sativa L.) may help in this regar d. The objectives of this central Georgia study were to determine beef steer (Bos taurus x B. indicus) performance and plant persistence as affected by endophyte infected (E+) and E- Jesup tall fescue, alfalfa, and grazing pressure (GP) during spring and autumn on continuously st ocked pastures. No grazing was done during summer. Average daily gain (ADG) from March to June for 3 yr on E+ tall fescue, E- tall fescue, E + fescue with alfalfa, and alfalfa alone were 0.95, 2.50, 1.24, and 2. 14 lb at low GP and 0.66, 2.04, 1.22, and 1.45 lb at high GP, respecti vely. High GP had a detrimental effect on ADG, and this effect was gre ater from October to December than in spring. Higher stocking rates we re needed on E+ than on E- tall fescue to achieve similar GP. Both Eand E- tall fescue survived well after a severe drought the first graz ing season, indicating good drought tolerance of the Jesup cultivar. A lfalfa with E+ tall fescue improved ADG by 30% at low GP and 84% at hi gh GP, even though the legume represented only 6% of the available for age. The high ADG obtained on Jesup E- tall fescue and excellent stand persistence indicate its potential for grazing by growing animals.