Physical composition of carcass and meat characteristics of beef cattle finished in feedlot with different diets

The effects of different diets on the carcass and meat characteristics of beef steers in feedlot were evaluated using the following: diet containing corn silage, with fixed formulation during the period of feedlot (CSF); diet containing corn silage, with variable formulation according to the phase of feedlot (CSV); diet containing sugar cane silage with fixed formulation (SCSF); diet containing sugar cane silage, with variable formulation (SCSV); CSV diet in initial half of feedlot and SCSV diet in final half (SCSV/CSV). A completely randomized experimental design with five treatments and three replicates (collective pens) was used. There was higher content of kidney-pelvic-inguinal fat (P=0.03), subcutaneous fat (P=0.06), and fat tissue (P=0.06) deposition in animals fed diets containing corn silage (6.7kg, 6.2mm, and 34.6%) as compared to those fed sugar cane silage (5.3kg, 4.8mm, and 31.7%). A higher (P=0.05) yield of strip loin and rostbiff (% of hindquarter) were measured in carcasses from animals fed diets containing corn silage (10% and 6.9%) than in carcasses from animals fed diets containing sugar cane silage (9% and 6.6%). No effects of the diets on yield of primary meat cuts of the carcass (P > 0.1), cooking losses (P > 0.3), and shear force (P > 0.1), with averages of 23.4% and 4.4kgf/m(3). The adjustment of the diet formulation as the period of confinement and the exchange of silage did not affect the characteristics of carcass and meat. The use of sugar cane silage allowed carcasses with good finishing.