An evaluation of the production potential of six tropical grasses under grazing, 3. Responses to set stocking rates under continuous grazing [beef cattle; Setaria sphacelata; Digitaria eriantha; Pennisetum clandestinum]
1992
Evans, T.R. | Hacker, J.B. (Commonwealth Scientific and Industrial Research Organisation, St Lucia (Australia). Div. of Tropical Crops and Pastures)
The response of 3 setaria cultivars (Nandi, Kazungula and Narok), the setaria variety splendida, kikuyu grass, and pangola grass to stocking rates of 4-6 steers per ha under continuous grazing was evaluated over a 3-year period. On a year-round basis, averaged over stocking rates, liveweight gain per ha ranged from 822 kg on Narok (164 kg per steer) to 568 kg on Kazungula (114 kg per steer). Narok produced the highest weight gains in summer and winter (142 and 23 kg per steer, respectively). The greatest winter weight loss was from steers grazing Nandi and Kazungula (both 15 kg per steer). Animal production in a year of above-average rainfall, in both summer and winter periods, was markedly reduced overall, even though the quantity of feed on offer was increased. The year x grass interaction was statistically significant in summer, but year x stocking rate and grass x stocking rate were not. Species response to stocking rate showed a linear relationship between stocking rate and liveweight gain per steer, declining with increasing stocking rate, except for Narok setaria where the reverse occurred over the range of 4-6 steer per ha. The results support those previously published and demonstrate the species potential for good levels of animal production per ha and their ability to withstand high grazing pressures and to maintain weed-free pastures.
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