Akademik Veri Yönetim Sistemi
REVUE DE MEDECINE VETERINAIRE, cilt.164, sa.1, ss.39-44, 2013 (SCI-Expanded)
The effects of brewer's yeast (Saccharomyces cerevisiae) as a substitute for vitamin and trace mineral premix in broiler diets on some performance parameters and tibia ash proportions have been investigated. For that, 400 one-day old male broiler Ross-308 chickens were assigned to 5 equal treatment groups (allotted in 4 pens of 20 birds): a group was fed with diets containing recommended vitamin and trace mineral contents during the starting, growing and finishing periods and served as a positive control group, and the birds from the other 4 groups received diets depleted in vitamins and trace minerals by 75% supplemented by 0% (negative controls), 1, 3 and 5% brewer's yeast, respectively. Vitamin and mineral depletion has significantly decreased weight gains and food intakes determined for the growing and finishing periods and yeast addition whatever the dosage, has not prevented the negative effects on growth performance, particularly in the last period. The various dietary treatments have not significantly modified weights of visceral organs (gizzard, heart, spleen, liver and bursa of Fabricius) but abdominal fat deposits were markedly enhanced when 5% yeast was added to the vitamin / trace mineral depleted diets. Tibia ash amount was greatly diminished in birds fed with depleted rations and the bone effect was reversed in groups supplemented with 1% to 5% yeast. The results indicated that performance parameters were depressed by reduction of dietary vitamin and trace mineral content throughout the growing period independently of the yeast addition whereas the negative bone effects were prevented by the inclusion of yeast in broiler diets.