Sugarcane tops as a substitute for sugarcane in high-concentrate diets for beef bulls

Abstract

Our objective was to evaluate the productive and economic performances of bulls fed increasing levels of sugarcane tops, as a substitute for sugarcane. Sixteen, 24-month-old, Nellore bulls (initial bodyweight = 360 ± 14.7 kg) were kept in a feedlot for 84 days, receiving a high-concentrate diet (80 : 20 concentrate : roughage ratio). Four levels of substitution were evaluated: T0 = no addition of sugarcane tops; T33 = 33% substitution; T66 = 66% substitution; and T100 = total substitution of sugarcane by sugarcane tops. Dry matter, organic matter, crude protein and neutral detergent fibre intake, bodyweight gain, feed conversion and feed efficiency were evaluated as productive performance parameters, and as economic indicators, total revenue, total operating expenses, gross margin, and net margin. No effect (P ≥ 0.66) of diet was found for the studied variables. Average values of total bodyweight gain, average daily gain, feed conversion, and feed efficiency were 102 ± 10.0 kg/animal, 1.2 ± 0.12 kg/day, 8.6 ± 0.72 and 0.12 ± 0.010, respectively. Unlike other treatments, the T100 net margin was positive, because of the lower cost of acquiring sugarcane tops compared with sugarcane. Partial or total substitution of sugarcane by sugarcane tops in high-concentrate diets did not affect performance of feedlot bulls, but total substitution reduced production costs, with positive net margin. We conclude that sugarcane tops can be utilised as a low-cost roughage source in diets for beef bulls.