The carcass physical composition, meat quality and cholesterol content in the Longissimus dorsi muscle of 24 Red Angus steers finished in feedlot with different weights were evaluated. Steers average age and weight at the beginning of the feedlot were, respectively, eight months and 189 kg. The number of days on feed was 114, 144, 173 and 213 days to reach the slaughter weight (PA) of 340, 373, 400.6 or 433.6 kg. The carcass composition was affected by the slaugther weight, with a quadratic response for bone percentage (%bone= 92.81 -- 0.402PA + 0.0005PA²), being the minimum value of 12% at a PA of 402 kg. The muscle percentage decreased linearly (%musc.= 78.38 -- 0.042PA) while the fat percent increased (%fat= 3.92 + 0.052PA). The edible portion:bone ratio showed a quadratic relation with slaughter weight (EP:B= -31.88 + 0.194PA -- 0.0002PA²) showing the maximun value of 6.47 for the carcasses produced by animals slaughtered with 395 kg. Muscle:bone ratio did not change with slaughter weight, being the average of 4.4 for all slaughter weights. Meat color and texture were not affected by slaughter weight, while marbling score increased linearly (Marb.= -13.35 + 0.051667PA). Increasing the slaughter weight resulted in lower thawing losses and higher cooking losses. The meat tenderness was not affected by slaughter weight and was classified as tender and very tender. Meat juiciness and palatability were sligthtly above average. The Longissimus dorsi ether extract concentration and cholesterol content were not affected by slaughter weight being 2.35% and 43.07 mg of cholesterol/100 g of muscle, respectively.
Bos taurus; fat; marbling; meat tenderness; muscle
