ECONOMIC COMPARISON OF NUTRITIONAL MANAGEMENT STRATEGIES FOR VENEZUELAN DUAL-PURPOSE CATTLE SYSTEMS

Objectives of this study were to compare three nutritional management strategies for dual-purpose herds in Venezuela in 1987 using a determi nistic, multiperiod linear programming model of a representative farm. The model maximized discounted net margin (total revenues minus varia ble costs) from the herd for a 3-yr cow replacement cycle partitioned into six periods. The periods accounted for seasonal variation in fora ge availability and quality, and the model provided information about optimal animal inventories, animal sales, land in forage, and feed sup plements. We compared current nutritional management practices and alt ernatives allowing optimal supplementation with commercial concentrate , molasses, cassava root, and urea. Iteration between the programming model and results from the Cornell Net Carbohydrate and Protein System assured technical coefficients consistent with predicted animal perfo rmance. Compared with management practices relying on commercial conce ntrate, optimal use of molasses and urea permitted increases in the st ocking rate. Productivity and profit were restricted primarily by ener gy intake, which was constrained by intakes of NDF and DM. Alternative management strategies changed the relative importance of nutrient req uirements and feed intake constraints. Thus, optimal interventions to alleviate nutritional constraints will vary with current management. M obilizing adipose and protein tissues during lactation was optimal for most strategies. Supplementing with molasses and urea instead of comm ercial concentrate was the most profitable strategy, increasing herd n et margin by 16% compared to the predominant feeding strategy in the l ate 1980s.