Effect of stocking rate, fodder conservation and grazing management on the performance of wether sheep in south-west Victoria. 1. Wool production

Abstract

In a 4 x 4 x 3 factorial experiment lasting three years, the effects of stocking rate, fodder conservation and three grazing management systems (continuous, deferred and rotational) on the wool production of wethers grazing perennial pasture were assessed. The hay conserved on the plots was fed to the sheep in such a way that the quantities made and fed would balance over a period of years. At the highest rate of stocking some oats were fed in adverse seasons. Stocking rate had the major effect on wool production in all years. Improving wool production by fodder conservation was shown to depend on stocking rate, grazing management and the seasonal conditions. In some instances fodder conservation was shown to interact with stocking rate in a manner such that the maximum response tended to occur when smaller proportions of area were conserved as stocking rate increased. The implications of this interaction are discussed. Fodder conservation increased wool production in the continuous and rotationally grazed systems in all years, but did not in two of the three years with deferred grazing. The biggest increases in wool production due to fodder conservation occurred in the third year, the driest on record when a drought reserve was used. Wool production was also influenced by the grazing management. In alt-years there was a consistent interaction with stocking rate in which the highest wool production was produced in the rotational system at high stocking rates and in the deferred system at low stocking rates.