Nutrient intake, productive and metabolic parameters of Nellore bulls feed a forage free diet using cottonseed cake as a fiber source.

We hypothesized that cottonseed cake in confined Nellore young bulls' diet as fiber source, could maintain or improve the nutrient intake, and productive and metabolic parameters. It was evaluated the total replacement of whole plant corn silage (WPCS) by cottonseed cake (CSC) as a source of fiber in the diet. A completely randomized design with two treatments and 12 replications was used. The treatments were two experimental diets containing 300 g/kg of WPCS or CSC as roughage. All animals at 0, 15, 30, 60 and 112 days were weighed to monitor productive performance and nutrient intake. Dry matter intakes, organic matter, neutral detergent fiber, physically effective neutral detergent fiber, crude protein and non-fiber carbohydrates of the WPCS treatment cattle were higher (p < 0.05), and the ethereal extract intake of cattle fed CSC diet was higher. The BW of cattle fed WPCS was higher in the two initial periods of confinement (p < 0.05). Animals from both treatments showed linear growth during the confinement period. There was a fiber source × period interaction for total weight gain (TWG), average daily gain (ADG) and feed efficiency (FE) (p < 0.05), with the lowest in the first 15 days and the highest at 30 days, reflecting a compensatory gain in animals fed with CSC. Bulls fed with CSC showed negative TWG and ADG in the first period (p < 0.05), but recovered in the following periods, surpassing that of the SC treatment in the last two periods. There was negative EF of bulls fed with CSC in the first period (P < 0.05), but in the following periods the CSC diet did not differ from the WPCS diet. The animals fed CSC diet showed a higher concentration of cholesterol and glucose in the blood plasma (p < 0.05). The forage-free diet containing cottonseed cake as a source of fiber replacing corn silage promoted better animal performance.

Cotton cake as an economically viable alternative fibre source of forage in a high-concentrate diet for finishing beef cattle in feedlots.

Cotton cake can be a sustainable and economically viable alternative to maize silage as an effective fibre source in the finishing diet of feedlot beef cattle. Thus, the objective was to evaluate the economic viability and the productive performance of Nellore steers finished in feedlots using cotton cake as a source of fibre, replacing maize silage in the diet. Twenty-four non-castrated Nellore steers, with an average weight of 377.8 kg and an age of approximately 24 months, kept in individual pens, were used. The diet was 30% roughage, in the form of maize silage, and a diet without forage containing 30% cotton cake as an effective fibre source, based on dry matter. The design used was completely randomised with two treatments and 12 replications. Effects (p < 0.05) of the dietary fibre source were observed for final body weight (BW), total weight gain, hot carcass weight (HCW) and carcass yield (CY). Revenue and net margin were higher for the treatment with cotton cake. The corn silage diet promoted higher total costs per animal (U$ 408.41 vs. U$ 336.06) and daily costs (U$ 3.65 vs. U$ 3.00). Greater differences were observed between fibre sources for the concentrate cost, and the maize silage diet had a cost U$ 98.29 higher than the treatment with cotton cake (U$ 314.04 vs. U$ 215.75). The cotton cake treatment had a higher cost of U$106.98/animal for the net margin. Cotton cake is a viable alternative and can be used as a source of fibre in forage-free diets without affecting production performance, promoting benefits in economic performance for finishing beef steers in feedlots.