The Effect of Organic and Inorganic Aflatoxin B1 Absorbents on in Vitro Digestibility and Rumen Fermentation Characteristics

Introduction Aflatoxins (AF) as secondary metabolites are produced by Aspergillus flavus and Aspergillus parasiticus. The most abundant aflatoxin B1 (AFB1) is toxic and carcinogenic to humans and animals. Utilization of mycotoxin adsorbents are noted as the most practical methods for protection of feed ingredients. The purpose of this study was to investigate the effect of organic and inorganic adsorbents for the adsorption of AFB1 and its effects on dry matter digestibility and rumen fermentation characteristics.Materials and Methods The experimental diet was a mixture of alfalfa silage and concentrate. Procedure of in vitro batch culture was performed according to the Menke and Steingass procedure. In an anaerobic condition, 30 ml of buffered rumen fluid was dispensed with pipetor pump into a 120-ml serum bottle containing 0.5 g DM of the experimental diet. The content of each bottle was contaminated with 0.5 ppm AFB1. Experimental treatments were: the control diet, commercial bentonite, activated bentonite, activated charcoal, the cell wall of Saccharomyces serevisia with 75% purity, bentonite + activated charcoal + yeast, (0.5 + 0.4 + 0.1 percent), bentonite + activated charcoal + yeast, (0.4 + 0.45 + 0.15 percent) and , bentonite + activated charcoal + yeast(0.3 + 0.5 + 0.2 percent) The amount of absorbents for all treatments was 1% of the experimental diets. All bottles were purged with anaerobic CO2, sealed with rubber stoppers and placed in a shaking water bath for 72 h at 38.6 degree centigrade. The amount of produced gas was recorded at 2, 4, 6, 8, 12, 16, 24, 48 and 72 h of the incubation. At the end of incubation, all the bottles were transferred to refrigerator to stop fermentation, and then opened. After pH measurements 2-ml sample of each filtrate bottle was taken and frozen at 20 degree centigrade after acidification with 2-ml of 0.2 N HCl. The biomass residues were centrifuged at 1000×g for 10 min at 4 degree centigrade. The supernatant in each bottle was decanted and the pellet was dried at 65 degree centigrade to a constant weight for the determination of the residues.Results and Discussion Absorbents addition increased the amount of produced gas in all treatments in comparison with the control treatment significantly (P