Tifton 85 Bermudagrass Pastures Stocked Continuous or Rotationally with Weaned Calves At Two Stocking Rates.

Tifton 85 bermudagrass stocked continuous or rotationally with weaned calves at two stocking rates

F.M. Rouquette, Jr., J.L. Kerby, G.H. Nimr, and K.D. Norman

Texas AgriLife Research and Extension Center, Overton, TX

Stocking strategies are often implemented to enhance forage utilization in pasture management systems. Objectives of this 3-year experiment with Tifton 85 bermudagrass (Cynodon dactylon L. Pers), were to assess gain per animal and per ha as affected by stocking methods (MTH) of continuous (CON) or rotational (RTN) stocked pastures at different stocking rates (SR). Two SR were assigned to 3 replicate pastures each of CON and RTN in 2008, 2009, and 2010. Average daily gain (ADG) of stockers from late-June to early Oct was affected (P<0.0001) by Year, SR, Year x SR, and Year x MTH.  Stocker ADG was greater for low (LO) vs high (HI) SR at 0.88 vs 0.70 kg da^-1 (2008); 0.53 vs 0.34 kg da^-1 (2009); and 0.58 vs 0.21 kg da^-1 (2010). The ADG was similar between CON and RTN in both 2008 (0.79; 0.79 kg da^-1) and 2009 (0.40; 0.46 kg da^-1). Using 318 kg = 1 stocker-equivalent, SR were increased from 2008 to 2010 with LO ranging from 8.6 to 13.4 an ha^-1 and HI ranging from 11.2 to 19.7 an ha^-1. With increased SR in 2010, ADG was greater (P<0.001) from RTN at 0.47 kg da^-1 vs CON at 0.31 kg da^-1. Differences between CON and RTN occurred only at increased SR in which forage mass restricted ad libitum intake, and forage allowance favored RTN pastures. The low SR in 2008 provided for higher ADG and resulted in about 875 kg ha^-1 regardless of SR or MTH. Increasing forage utilization with higher SR decreased ADG and gain per ha and may not be a viable, economic management strategy.