The University of Arizona

A comparison of frontal, continuous, and rotation grazing systems.

J.D. Volesky, F. de. Achaval O'Farrell, W.C. Ellis, M.M. Kothmann, F.P. Horn, W.A. Phillips, S.W. Coleman

Abstract


Two 2-year trials were conducted to evaluate and compare frontal, continuous, and 2-paddock rotation grazing systems on 'Plains' Old World bluestem (Bothriochloa ischaemum (L.) Keng.). Frontal grazing allows livestock a continuous opportunity to graze fresh forage via a livestock-pushed, sliding fence which allocates and controls grazing within a pasture. Trial 1 treatments included frontal grazing at a very high stocking density of 13.3 head ha-1 and continuous grazing at 4 stocking densities described as low, moderate, high, and very high. The mechanical design and components of our frontal grazing system were quite adequate in terms of the system's operation and interaction with the livestock herd. Significant (P < 0.05) linear relationships were found for regressions of daily gain on stocking rate and grazing pressure index, and for gain ha-1 on stocking rate and grazing pressure index. Year effects were evident in all regressions. Trial 2 treatments included frontal, continuous, and rotation grazing systems initially stocked at 6.7 head ha-1. Mid-season reductions in stocking density were made in continuous and rotation grazing to ensure that these treatments would have adequate forage to continue until frontal grazing completed its second cycle and to achieve an end-of-season standing crop which was similar in all 3 treatments. Season-long daily gains under frontal grazing were not significantly different compared to continuous grazing (P > 0.05); however, they were less than those under rotation grazing (P < 0.05). Frontal grazing provided about 100 more steer-days per hectare of grazing than either continuous or rotation grazing. However, steer production was not significantly different among treatments and averaged 296 kg ha-1 (P > 0.05).

Keywords


grassland improvement;controlled grazing;liveweight gain;Bothriochloa ischaemum;stocking rate;rotational grazing;Oklahoma;grazing intensity;cattle;seasonal variation

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