Use of maize silage in beef heifers fattening diets: effects on performance, carcass and meat quality

The technical and economic interest of fattening beef heifers with maize silage as an alternative to conventional feeding on concentrates was analyzed in a commercial farm. Heifers received ad libitum during the fattening phase (from 6 months of age till they reached 440 kg live weight) either a total mixed ration of maize silage and a high-protein concentrate (TMR, n=8) or concentrates and barley straw (CONC, n=8). Growth performance was similar for both treatments, and although total feed consumption and feed:gain ratio were higher in the TMR group, the economic cost per kg gain was 11% lower in this group. Carcass weight and conformation score were similar, but carcasses from the TMR had a slightly lower fat score and higher pigment content in subcutaneous fat. Meat instrumental quality (pH, colour, shear force) were similar in both treatments, but fatty acid profile differed between diets, with a higher proportion of n-3 polyunsaturated fatty acids and a lower n-6/n-3 ratio in meat from TMR heifers, which indicates a healthier nutritional quality.