Bio-economic evaluation of stocking rate and supplementary feeding of a beef herd

Abstract

The effect of varying price ratios between liveweight and supplementary feed on the optimum stocking rate (SR) of a beef herd on range is analyzed in relation to the net value of weaned calf live weight. While the basis for determining optimum stocking rate is generally the value of production and costs per unit area, the animal performance per se is often a major management criterion, especially where the capital investment in livestock is high and where risk avoidance is an important consideration. Consequently, equations expressing the net value of beef production per unit of land and per animal unit are formulated as a function of SR. Parameter values for the equations were taken from a grazing trial conducted in the Galilee in Israel where a beef herd was maintained yearlong on native range 5 years at 3 different SR's, 0.50, 0.67, and 0.83 cows/ha. The animals were supplemented ad libitum with poultry litter during the dry summer months. During the transitional period between the opening rains and range readiness, poultry litter was enriched with 20% barley grain. In addition, straw was given at an average rate of 80 to 375 kg/ha in the intermediate and highest stocking rates. Over the range of SR's studied, it was shown that when supplementary feed and other per animal costs are high, net value of production per unit area of range declines with SR even though total production increases. On the other hand, when fixed range and management costs are high, the net economic benefit per cow increases with SR even though production per cow decreases. It is concluded that the optimum SR for a given situation depends not only on the input/out price ratios but also on the criterion for evaluating economic value that is most revelant to the manager.