ECONOMIC ANALYSIS, CARCASS AND COMMERCIAL CUTS YIELDS OF 5/8 HEREFORD 3/8 NELLORE CULL COWS SLAUGHTERED AT DIFFERENT FATNESS DEGREES

Abstract

The objective of this work was to study the effect of the fatness level on carcass and commercial cuts yields of 5/8 Hereford 3/8 Nellore cull cows, as well as to perform the economic analysis of the marketing of these cuts by the slaughterhouse industry. We used 42 adult cows, all with eight teeth at slaughter, and average live body weight of 530 kg. The experimental design was completely randomized. After slaughter, the carcasses were classified in relation to fat cover, and separated into fat 1 (absent), fat 2 (scarce), fat 3 (median) and fat 4 (uniform), according to the “Sistema Nacional de Tipificação e Classificação de Carcaças Bovinas”. Body weights at origin were higher for cows of fat class 4 in relation to class 2 and 1, being 571.9, 517.6, and 488.1 kg, respectively, not differing from fat class 3 (536.6 kg). The hot carcass yields increased as a function of the increase of the degree of carcass finishing, with mean values ??of 44.4, 46.1, 47.9 and 47.8% for fat classes 1, 2, 3 and 4, respectively. The cut of the rib is the cut with the largest increase in weight when the fat level increases. Considering the commercial cuts prices at the wholesale markets of São Paulo and Rio Grande do Sul, the industry could pay better prices for cows with fat 2 in relation to the other classes. The break-even point of the slaughterhouse industry would be R$ 6.21/kg of carcass for fat 2 cows, against R$ 6.02/kg, R$ 5.99/kg and R$ 5.98/kg, respectively, for fat 1, 3 and 4 cows.

KEYWORDS: beef cows; Braford; fat thickness; rib cut yield; saw cut yield.