The effects of cocoa meal (FC) or palm kernel cake (TD) replacing corn and soybean meal standard concentrate on physical-chemical composition were evaluated and the economical analysis of milk production was performed. Five Saanen goats, with 41.66kg body weight and 60 days of lactation were used in a 5×5 latin square experimental design. The experimental periods of 14 days, had 10 days for adaptation and four days for data collection. The isoprotec diets (13.2%), were formulated to allow a milk production of 2kg/day. The diets were constituted of 36% roughage and 64% concentrate. The standard concentrate was replaced by 0, 15 and 30% of FC or TD. No effects of diets (P>0.05) on milk physical-chemical characteristics were observed. The inclusion of by-products reduced the cost of diets, however, only those with 15% FC and 15% TD showed gross margin higher than the one observed for the control diet.
goat; economical evaluation; milk composition; by-product