Replacement of corn by glycerine and vegetal oils (cashew and castor oils) as alternative additives feeds in diets of Purunã bulls finished in feedlot

Glycerine a co-product from the biodiesel industry and cashew and clove oils could be an alternative food for replacing corn as an energy source and synthetic additives commonly used in feedlot diets. This work was realized to study the effects of replacing corn grain with glycerine and vegetal oils (nut shell liquid and castor oils) on animal performance, feed intake, feed efficiency and apparent digestibility of Purunã bulls finished in feedlot. A total of 32 Purunã bulls (¼ Aberdeen Angus + ¼ Caracu + ¼ Charolaise + ¼ Canchim) with a mean age of 32 ± 2.0 months and a mean body weight 206.1 ± 20.0 kg were distributed in a completely randomized design with four diets and eight replications per diet. The four experimental diets were as follows: CONT – basal diet; VOIL –basal diet and addition of vegetable oils (3 g/animal/day); GLYC – basal diet and addition of glycerine (20.1% glycerine on a DM basis); GLVO – basal diet and addition of glycerol (20.1% glycerine in DM basis) and vegetal oils (3 g/animal/day). Final body weight and average daily gain were similar (P > 0,05) among bulls from four diets. There was an increase (P < 0,05) in hot carcass weight and the dressing percentage when VOIL, GLYC, and GLVO were included in the diet. The VOIL diet increased (P < 0.05) the DM intake and other nutrients in comparison to CONT diet. DM efficiency was similar (P > 0.04) among the four diets. The GLYC and VOIL diets reduced (P < 0.05) the NDF intake (10.0 and 18.9%) in comparison to the CONT and GLVO diets, respectively. However, bulls fed GLYC and GLVO diets had a high (P < 0.05) intake of metabolizable energy when compared to bulls fed diets without glycerin. The apparent digestibility of DM, OM, CP, TC, NFC, and NDF was higher (P < 0.05) when glycerin was added to the diets; whereas no change was observed in the apparent digestibility of EE, ADF, and CF. In conclusion, diets containing glycerine and vegetal oils did not change average daily gain; however, they improved the carcass weight, the feed intake, and the apparent digestibility.