The carcass characteristics of 43 livestock cows of the Purunã breed, with an average age of 68.02 ± 17.36 months and of different weights at slaughter, were evaluated. The experimental design was completely randomized, with slaughter weights of 401; 434; 461; 476 and 522 kg being evaluated. The increase in slaughter weight from 401 to 522 kg, promoted a gain in weight and in the hot and cold carcass yield of 34.7; 36.6; 2.1 and 5.13 respectively. The subcutaneous fat thickness (mm) increased linearly with increasing slaughter weight, going from 1.11 to 4.79 mm. The area of the Longissimus dorsi, expressed as a function of the cold-carcass weight varied quadratically with increasing slaughter weight, with the smallest value being estimated for a slaughter weight of 440 kg. The amount of muscle, fat and bone increased by 300; 330 and 69g for each additional kilogram of slaughter weight respectively. The edible portion of the carcass increased by 34.1% with the increase in slaughter weight from 401 to 522 kg. Raising the slaughter weight represents a great potential for increasing meat production in the country, given the significant number of female livestock slaughtered annually. However, based on the production system, and considering the current method of remuneration, the slaughter weight of livestock cows should not exceed the minimum requirements of slaughterhouses, in view of the reduced feed efficiency which accompanies increasing body-fat deposits.
Carcass yield; Beef; Subcutaneous fat thickness
