Rotational vs. continuous stocking of beef cows and calves on mixed endophyte-free tall fescue-bermudagrass pasture.

摘要

Endophyte-free tall fescue (Festuca arundinacea) furnishes better animal performance than endophyte-infected grass but is less persistent under grazing, especially in mixture with common bermudagrass (Cynodon dactylon). Rotational (RS), compared with continuous (CS), stocking of endophyte-free tall fescue may improve persistence when grown with an aggressive warm season perennial grass. In a field experiment at Eatonton, Georgia, F. arundinacea cv. AU Triumph (endophyte-free) was sown on 4 mowed (3-inches height) 40-acre bermudagrass swards. Rotationally grazed plots were divided into 12 paddocks to allow 2 days of grazing and 22 days of rest. Twenty Hereford (Bos taurus) X Brangus (B. indicus X B. taurus) beef cows/40-acre pasture were maintainedyear around for 3 years with additional cows added in spring and summer to maintain similar forage availability. Grazing method had no effect on live weight change, pregnancy rate or calf weaning weight. Stocking rate and calf weaning weight/acre were 38 and 37% higher, respectively, and winter hay consumption was 31% lower from rotationally stocked pastures because of better tall fescue persistence and forage availability. Crude protein (CP) and in vitro dry matter digestibility of available forage generally exceeded 8 and 50%, respectively, throughout the year. It is concluded that rotational grazing is useful in maintaining stands of endophyte-free tall fescue in bermudagrass pastures.