Wednesday, November 15, 2006

Influence of a Mono-crop vs. a Mixture and Pasture Planting Method on Cool Season Forage Availability for Grazing by Beef Cattle.

Robert Myer, Ann Blount, and Tim Hewitt. University Of Florida, "Nfrec, 3925 Highway 71", Marianna, FL 32446, United States of America

A 2 yr study was done to evaluate two annual cool season forage treatments [ryegrass + oats (ORG) vs. ryegrass only (RG)] and two pasture planting/cultivation methods [prepared seedbed (PS) vs. sod-seeding (SS) into dominant bahiagrass].  Eight, 1.33 ha pastures were utilized during the 2003-04 and 2004-05 winter spring-grazing seasons.  The PS pastures were planted in Oct each year into clean-tilled seedbeds and the SS were planted with a no-till seed drill in Nov when bahiagrass (Paspalum notatum Fluegge) became dormant.  The pastures were grazed by growing beef heifers (average initial weight of 287 and 250 kg for yr 1 and 2, respectively).  Each pasture was grazed by four “tester” cattle and “put and take” cattle were added as necessary.  The grazing season ended in Apr (’04) and May (’05).  The average number of animal grazing days ha-1 yr-1 was 470, 372, 336 and 301 for PS-ORG, PS-RG, SS-ORG and SS-RG treatments, respectively (SE = 30).  Average forage DM yield kg ha-1 yr-1 was 4536, 3624, 3430 and 3294 (SE = 247); average daily gain kg d-1 of tester cattle was 1.05, 1.14, 1.00 and 1.10 (SE = 0.036); and estimated cattle weight gain kg ha-1 yr -1 was 485, 412, 316 and 320 (SE = 37) for the above treatments, respectively.  Pasture cultivation/planting method affected grazing days (P = 0.01), forage DM yield (P = 0.03) and total gain (P = 0.01), but not ADG (P>0.10).  Utilization of a forage mixture vs. a mono-crop increased grazing days (P = 0.07) and forage DM yield (P = 0.08), but ADG was decreased (P = 0.04); total cattle weight gain ha-1 was unaffected (P>0.10).