Effect of the supplementation of biocomplexed minerals in diets for free-range chickens on performance and carcass characteristics

ABSTRACT We intended to evaluate the influence of supplementation with biocomplexed minerals on the performance and carcass characteristics of Label Rouge broilers of both sexes, as well as on the feed efficiency and feed costs. The experimental design was completely randomized arranged in factorial scheme (3×2) – three experimental diets (control, 0.50 ppm of selenium, and 0.40 ppm of chromium) and two sexes (male and female). Each treatment was composted of three plots, each one represented by 21 birds. The average weight (g/bird), weight gain (g/bird), feed intake (g/bird), and feed conversion in periods of 1 to 7, 1 to 21, 1 to 35, 1 to 49, 1 to 63, and 1 to 90 days were calculated. Weight and yield of carcass and cuts were determined. Both average feed cost (AFC, R$/bird) and cost per kg of weight gain (CWG, R$/kg weight gain) as well as economic efficiency index (EEI) were estimated. There was no influence of the diet on performance, carcass characteristics, and feed costs of the birds. The males presented higher means of average weight (3819.2 g/bird), weight gain (3780.9 g/bird), feed intake (11030.2 g/bird), and better feed conversion index (2.9) in the period of 1 to 90 days, besides presenting higher values of live weight at slaughter (3740.2 g), carcass weight (3117.5 g) and carcass yield (83.4%), breast weight (832.4 g), thigh weight (432.5 g), and thigh yield (13.9%); the females presented higher breast yield values (28.1%). The males presented higher AFC and lower CWG. The addition of minerals in the diet does not change performance, carcass characteristics and feed costs. The males present better performance and better carcass characteristics, in addition to being economically more viable.