[Influence of manioc and other industrial by-products in calf fattening: productive parameters and carcass and meat quality]

Eighteen five-month-old Charolais x Montbeliarde female calfs of 160 kg live weight, separated into three lots of six animals each, were fattend with isocaloric (ME=2.98, 3.04 and 3.06 for lots 1, 2 and 3 respectively) and isoproteic (GP=16.99, 16.01 and 16.99 for lots 1, 2 and 3 respectively) feeds composed of decreasing amounts of cereals and increasing amounts of agroindustrial byproducts and ceral substitutes, until slaughter at 400 kg live weight. The effects of the diet on the productive parameters and the quality of carcass and meat were studied. Feeds composition and percentage inclusion were as follows: Feed 1 (Control): barley (40 per cent), corn (36 per cent) and soya meal (21 per cent). Feed 2 (Gluten): barley (35 per cent), corn (27 per cent), soya meal (15 per cent) and corn gluten feed (15 per cent). Feed 3 (Manioc): barley (38 per cent), soya meal (16 per cent), corn gluten feed (25 per cent) and cassava meal (9 per cent). No significant differences were found (P0.05) between lots for growth rate, feed intake, feed conversion index, carcass weight and dressing percentage. Carcass conformation, carcass fat, kidney-pelvic fat, tissue composition at the 10th dorsal rib, and fatty acid composition of the subcutaneous fat were not significantly different (P0.05) among diets. Neither were significant differences (P0.05) found between lots in the pH at 24 hours, meat color (logissimus dorsi muscle), color of subcutaneous fat, kidney-pelvic fat and other meat quality parameters evaluated at the longissimus dorsi, such as meat toughness, dry matter content and water retention capacity. The sensory test on the meat (longissimus dorsi) did not show significant differences (P0.05) between diets as for tenderness, juiciness and global appraisal, except for flavor. It can be concluded that the substitution of cerals by agroindustrial byproducts or other substitutes allows an appreciable cost reduction in calf intensive fattening without effect be it on productive parameters of the animals or on meat and carcass quality.