Nitrogen fertilization, stocking rate and rotational grazing effects on steers grazing Pennisetum clandestinum.

Abstract

Kikuyu pastures at the Ukulinga research farm near Pietermaritzburg were fertilized with 150 and 300 kg nitrogen (N) ha -1 in the summer periods of 1985-86 and 1986-87, and were continuously grazed with steers at stocking rates of 5.4, 8.0 and 10.7 steers ha -1. In the second season the high N level pasture was also grazed under 12-paddock rotational grazing at stocking rates of 5.4, 8.0 and 13.4 steers ha -1. In the first season the high N level provided higher (P < 0.05) animal weight gains, but there was no difference between N levels in animal weight gain during the second season. Rotational grazing provided higher weight gains than continuous grazing in the second season. The increased weight gains obtained from high N fertilization and rotational grazing were probably caused by higher forage availability rather than higher forage quality.

Keywords: average daily gain; continuous grazing; fertilization; forage quality; grazing; grazing effects; herbage availability; kikuyu; kikuyu pastures; nitrogen fertilization; pasture; pastures; pennisetum clandestinum; pietermaritzburg; rotational grazing; south africa; stocking rate; ukulinga research station