Carcass and meat characteristics of different cattle categories fed diets containing crude glycerin Características de carca a e da carne de diferentes categorias de bovinos alimentados com dietas contendo glicerina bruta

The objective of the present study was to assess the carcass and meat characteristics of cows and castrated crossbred steer from dairy breeds fed in a feedlot with different levels of crude glycerin in the diet. Twenty-four animals were used, 12 cows with 467 ± 15 kg initial bodyweight and 12 steer 347 ± 17 kg initial bodyweight. A complete randomized design in a 4 x 2 factorial arrangement (four crude glycerin levels and two animal categories) was used. The crude glycerin levels were 0, 60, 120 and 240 g/kg in dry matter diet, formulated with 800 g concentrate/kg dry matter. Including crude glycerin in the diet did not alter carcass weight and yield, backfat thickness and meat qualitative characteristics. Cows presented heavier hot carcass (279.4 versus 231.8 kg) with greater backfat thickness (3.8 versus 5.2 mm) than steer. Crude glycerin in quantities from 0 and 120 g/kg dry matter diet resulted in less muscle and greater fat participation in the cow carcass compared to the steer carcass. The cow meat was darker in coloring and had a higher degree of marbling than the steer. There was no difference for tenderness or total liquid losses during meat thawing and cooking between cows and steer. Crude glycerin can be added up to 240 g/kg diet dry matter for cows and steer from dairy breeds, because it does not decrease the quality of the carcass or the meat produced. Objetivou-se avaliar as características de carca a e carne de vacas de descarte e novilhos castrados mesti os de ra as de aptid o leiteira alimentados em confinamento com diferentes níveis de glicerina bruta na dieta. Foram utilizados 24 animais, sendo 12 vacas de descarte com peso corporal inicial de 467 ± 15 kg e 12 novilhos com peso corporal inicial de 347 ± 17 kg. O delineamento experimental foi o inteiramente casualizado, com os tratamentos em arranjo fatorial 4x2 (quatro níveis de glicerina bruta e duas categorias animal). Os níveis de glicerina testados foram de 0, 60, 120 e 240 g/kg de matéria seca de dietas formuladas com 800 g de concentrado/kg de matéria seca. A inclus o de glicerina bruta na dieta n o alterou o peso e o rendimento de carca a, a espessura de gordura subcutanea e as características qualitativas da carne. Vacas apresentaram carca as quentes mais pesadas (279,4 vs. 231,8 kg) e com maior espessura de gordura subcutanea (13,8 vs. 5,2 mm) que novilhos. A glicerina em quantidades de 0 e 120 g/kg de matéria seca da dieta proporcionou menor participa o de músculos e maior de gordura na carca a de vacas em rela o à carca a de novilhos. A carne das vacas apresentou colora