R. Bras. Zootec.01/Oct/2005;34(5):1640-50.
Effects of replacing corn with increasing levels of cassava starch by-products on carcass characteristics and meat for young bulls
DOI: 10.1590/S1516-35982005000500026
This trial was conducted to study the effects of replacing corn with increasing levels of cassava starch by-products on carcass and meat characteritics for fedlot young bulls. Percentages of substitution were 0, 25, 50, 75, and 100, in dry matter basis. Forty crossbred bulls (½ and ¾ Bos taurus x Bos índicus), averaging 21 months old and 363 kg of initial body weight and 570 kg of final body weight were assigned to a block design with eight replicates by treatment. No effect of treatment on carcass traits was detected. The averages were as follows: carcass yield, 54.79%; conformation, 12.32 (good +); carcass length, 132.5 cm; cushion thickness, 28.12 cm; ribeye area, 79.25 cm2; porcentages of bone, 15.51%, of muscle, 64.12%, and of fat, 20.85%; muscle + fat/bone relation , 5.52; edible portion percentage, 85.07%; fat thickness, 4.02 mm; and marbling, 3.9 (light -). No effect of treatment on chemical composition of meat was detected, with averages of 1.01; 19.16 and 2.24%, respectively, for ash, protein, and fat. There was significant difference for humidity, with higher percentage for 50% replacement diet (74.67%) and lower for 25% replacement diet (72.89%). The other treatments had intermediate values. No treatment effects were observed and mean values for the studied traits indicate that the obtained carcasses fulfill the expected requirements of market.
Keywords: animal feeding; beef cattle; cassava by-products; meat quality; nutritive value