Effects of animals on pasture production

Sheep and cattle pastures previously grazed for 2 years at 22.2 ewe equivalents/ha were subjected to a common defoliation regime in which animals were excluded (mowing and clippings returned). Sub plot treatments of N at 0, 90, and 270 kg/ha and of K at 0. 56, and 224 kg/ha were applied. Pasture yields, species composition and N and K concentrations and uptake were measured over 8 months. Sheep pastures produced 41% more dry matter than cattle pastures. Factors contributing to this difference were: (a) lower levels of available soil N on cattle pastures as indicated by a greater response to applied N — attributed in part to greater transfer of N into urine patches, (b) a lower percentage cf white clover in cattle pastures, (c) lower sward density and more bare ground in cattle pastures, and (d) losses of urinary N from the cattle farmlet during the additional 30 days they were fed on pads.