Ameliorative effect of glucomannan-containing yeast product (Mycosorb) and sodium bentonite on performance and antibody titers against Newcastle disease in broilers during chronic aflatoxicosis
The aim of this study was to determine the impact of aflatoxin (AF), yeast glucomannan (YG) and sodium bentonite (SB) on performance and immunization against Newcastle disease (ND) in broiler feed with naturally contaminated diet with aflatoxin. For this experiment, 300 7-day-old Ross 308-strain broiler chickens were chosen and randomly assigned to ten dietary treatments in three replicates of ten chicks. Treatments were: 1) diet free from aflatoxin (positive control group); 2) naturally contaminated diet with aflatoxin (negative control group); 3, 4, 5, 6, 7, 8, 9 and 10) naturally contaminated diet with aflatoxin supplemented with 1.5% SB, 3% SB, 0.05% YG, 0.1% YG, 1.5% SB + 0.05% YG, 1.5% SB + 0.1% YG, 3% SB + 0.05% YG and 3% SB + 0.1% YG, respectively. Chicken in each replicate were weighed weekly and feed intake, weight gain and feed conversion ratio were measured. Blood sample was taken from each bird and the titers of antibody against ND were measured by haemagglutination inhibition test. Aflatoxin in contaminated diet was measured and confirmed by thin layer chromatography (TLC) to be 250 ppb. Compared to the positive control diet, growth parameters were significantly (P<0.05) lower in 250 ppb aflatoxin fed chicks during experiment and also the antibody titer against ND was significantly (P<0.05) lower in the negative control diet from 35 to 42 days of age. The addition of yeast glucomannan and sodium bentonite, individually and in combination to the AF-containing diet ameliorated the adverse effects of aflatoxin, but 0.1% yeast glucomannan supplementation to the contaminated diet with aflatoxin proved to be much more effective in the amelioration of the adverse effect of AF on performance and humeral immunity against ND.
Key word: Aflatoxin, broilers, 0.1% yeast glucomannan, performance, Newcastle disease.