This study was conducted to evaluate the performance, carcass characteristics and chemical composition of Longissimusmuscle (LM) of the bulls. Twenty-four Nellore bulls were used in a complete randomised design. The bulls were randomly assigned to one of the three diets containing 0, 5 or 12% glycerin. Final BW and ADG were similar (P>0.05) between the bulls fed with 5 or 12% of glycerin but were higher (P<0.10) compared to the bulls fed without glycerin. DMI and feed efficiency was not affected (P>0.05) by glycerin level. Hot carcass weight increased (P<0.10) when glycerin was fed at 5%. Glycerin level did not affect (P<0.05) the dressing percentage and fat thickness. LM increased (P<0.10) when glycerin was fed at 12%. Dietary glycerin did not affect (P>0.05) the conformation, colour, texture, marbling and pH. There was difference (P>0.05) for moisture, ashes and crude protein among glycerin levels. Bulls fed 12% glycerin present the highest (P<0.03) total lipids on LM. The percentage of saturated fatty acids (SFA), monounsaturated acids (MUFA), polyunsaturated acids (PUFA), n-6 and n-3 fatty acids and PUFA/SFA and n-6:n-3 ratios of the LM were similar among the diets. In conclusion, glycerin level did not affect the animal performance and carcass characteristics of Nellore bulls finished in feedlot.

Two height cuttings of corn silage with or without enzyme inoculants were evaluated for 68 days on performance, carcass characteristics, meat quality and chemical composition of the Longissimus muscle in crossbred bulls (F1 - ½ Nellore vs. ½ Angus) finished in feedlot. Thirty-two 20-month-old bulls, with initial average weight of 374±25 kg, were kept in individual pens (10 m²). Diets consisted of 50% roughage and 50% concentrate, with an expected 1.80 kg/day weight gain. The experimental design with four diets and eight replications was completely randomized. Different cutting heights, low (25 cm) and high (45 cm), with or without enzyme inoculants, were studied. Live weight, average daily gain, feed intake, feed efficiency, carcass characteristics, muscle, fat and bone percentages at the 11th and 12th ribs, chemical composition of the Longissimus muscle, sum of saturated, mono-unsaturated, poly-unsaturated fatty acids, n-3 fatty acids, n-6 fatty acids, and the poly-unsaturated:saturated and n-6:n-3 relations were determined. Cutting height of silage corn and the use of inoculants did not affect final live weight, average daily gain, feed intake, alimentary efficiency of dry matter, carcass characteristics, meat quality, chemical composition of the Longissimus muscle or fatty acid profile. High cutting of silage corn (45 cm above the ground) and the use of inoculants are not necessary in the case of cattle finished in feedlot, with 1.8 kg daily gain.