Bio-economicity of the finishing phase on feedlot of crossbred young bulls slaughtered at different body weights

The objective in this work was to evaluate the economicity of the finishing phase on feedlot of F1 Red Angus x Nellore (1/2 RA 1/2 N) and Blond D'Aquitaine x Nellore (1/2 BA 1/2 N) crossbred young bulls slaughtered at 480, 520 and 560 kg of body weight. Thirty-six F1 crossbred young bull with 20 months of initial average age: 18 1/2RA1/2 N and 18 1/2N1/2 BA were allotted to a completely randomized design in a 2 x 3 factorial arrangement (genetic group x slaughter weight), with six replicates. The BA N young bulls slaughtered at 480 kg had the highest carcass gain (kg/day), feed efficiency, gross income (R$/day), gross profit of feed (R$/day), break-even cost of the diet (@/t DM) and cost: benefit ratio. The 1/2 BA 1/2 N young bulls also had higher dressing percentage than 1/2 RA 1/2 N young bulls. As the slaughter weight rised the dressing percentage, feed: gain ratio, feed cost (R$/@ and R$/day) and break-even point (kg/day) increased; while the gross feed profit (R$/@) decreased. The bioeconomic multivariate nutritional index had better association with the profitability of the finishing phase of beef cattle on feedlot. Sensitivity analysis did not influence the results obtained. The benefit was lower than the feed cost from exchange relation of four (4) @/t DM of the diet. F1 Blond D'Aquitaine x Nellore crossbred young bulls slaughtered at 480 kg of body weight showed the best bioeconomic efficiency.