Akademik Veri Yönetim Sistemi
REVUE DE MEDECINE VETERINAIRE, cilt.162, sa.11, ss.531-537, 2011 (SCI-Expanded)
The aim of this study was to investigate the effects of dietary supplementation with yeast products and/or hops on growth performance and intestinal morphology in broilers: A total of 360 one day old male broiler chickens were randomly divided into 6 equal groups according to the diet regimen: birds were supplemented for 42 days with 3% inactivated yeast or with 0.3% yeast culture or with 0.025% hops or with combination of yeast culture and inactivated yeast or hops whereas in the last group, broilers were not supplemented and served as controls. Body weights, weight gains, food intakes and food efficiency were determined at the 14th, 21st, 35th and 42nd days whereas carcass traits (carcass weight, dressing percentage and relative weights of liver, gizzard, bursa of Fabricius and abdominal fat as well as tibia ash) and intestinal morphology (intestinal pH, villus height and crypt depth) were explored on day 42 in 12 birds from each group. An early (within the first 21 days) but transient positive effect on growth (body weight and weight gains) compared to the controls was induced by the supplementation with hops or yeast culture whereas the growth appeared to be slightly delayed and the food efficiency was significantly altered on day 21 in birds supplemented both with yeast culture and inactivated yeast. None of the carcass traits were modified by the dietary inclusion of yeast products and/or hops and although birds treated with inactivated yeast alone have exhibited the lowest villas and crypt dimensions, no significant changes in the intestinal morphology was seen among groups. These results indicate that the yeast products and hops do not act as growth promoter in broilers reared under normal conditions except in the starter period and that co-supplementation with additives failed to exacerbate the growth performances.