Effectiveness of an organic selenium source for broiler chickens reared at high stocking density

Selenium is an important nutrient for poultry, particularly in its role on immunity and reproduction. It is supplemented to diets in inorganic or organic forms. In a 2 x 4 factorial experiment, 440 day-old male Ross-308 broiler chicks (46.5 ± 1.12 g) were reared at two stocking densities (32.1 or 48.1 kg/m²) and fed on diets without Se supplementation or a positive control (0.4 ppm Se from sodium selenate) or two levels of an organic product, BiOnyc® (0.1 or 0.4 ppm, BioProcessing Australia). Each treatment was replicated 5 times. The birds were changed to finisher diets at 22d, and maintained on the same supplements but on stocking densities of 29.9 or 49.1 kg/m² until 35d. Feed intake, weight gain and FCR (P<0.001) were reduced by increase in stocking density. BiOnyc®, improved weight gain, flock uniformity and FCR compared to the two control diets although this was not significant. Selenium retention and breast meat Se content tended to be higher in the BiOnyc® groups than on the controls. BiOnyc® had variable effects on blood parameters, increasing the PCV and Ca levels but reducing glucose. Meat quality, such as shear force, intramuscular fat, shelf life to 7 days and colour were not significantly different between the groups. The test product proved to be more effective than the inorganic Se source and would present savings on feed through increased improved FCR.