| The adsorption properties of bentonite to Methionine , Lysine , riboflavin , phosphorus , fluorin ,phytic acid and free gossypol, and the effect of bentonite on the activity of phytase were studied. The acute toxicity experiment of AFB1 to duckling with and without bentonite was carried out. The effection of anti-mould agent with carrier of bentonite was evaluated too in this paper.1 The experiment of adsorption in vitroThe adsorption to methionine and phosphorus by bentonite was little at the conditions of pH 2.0 and pH8.0.The maximum adsorptions were only 0 mg/g, 2mg/g at pH2.0 and 6.4mg/g, 41.2mg/g at pH8.0 respectively, methionine and phosphorus sorbed on bentonite can be mostly desorpted with the solution of pH 8.0 .The maximum adsorption to lysine by bentonite was 250mg/g at pH2.0 and 125mg/g at pH8.0,and the quantity of adsorption in the acidic condition is higher than that in the alkaline condition, lysine could be desorpted from lysine-bentonite complex with solution pH8.0,the rate of desorption was 97.97% and 15.15% respectively. The adsorption to riboflavin by bentonite is accordance to the Nernst formula, and the quantity of adsorption increased with the concentration of riboflavin increasing. The desorption rate of riboflavin from riboflavin-bentontie complex was 100% with the solution pH 8.0.Fluorin and free gossypol can be adsorped by bentonite in solution pH2.0 and 8.0, the adsorption increased with the concentration of fluorin and free gossypol increasing, the maximum adsorption rate were 47.6%, 78.9% at pH2.0 and66.5%, 100% at pH8.0 respectivly ,and only a little of fluorin and free gossypol were desorpted with solution pH 8.0 . The adsorption to AFBi by bentonite is accordance to Nernst formula, the quantity of adsorption increased with the concentration of AFB1 increasing,the maximum rate of adsorption were both 100% at pH2.0 and pH8.0, the rate of desorption following by at pH8.0 was 28.6% and 5.8% respectively. The competition adsorption test indicated that bentonite can sorpted AFB1 selectivity.The adsorption to phytic acid by bentonite is accordance to Nemst formula, the quantity of adsorption increased with the concentration of phytic-acid increasing, the adsorption rate was 66%. Bentonite can prompt the activity of phytase in the normal level, and protect phytase from heat treatment at 80 for 30min in wet condition.2 The acute toxicity experimentAFB1 at 0.4mg/kg.bw and 0.8mg/kg.bw of avoirdupois were administrate to three days old duckling by p.o.,the death rate within 72h are 70% and 100% of positive control group, and death rate are both 0% of bentonite group, the results suggested thatthe bentonite can reduce the harmful effect of AFB1 to animal. 3 anti-mould experimentDifferent anti-mould agents were prepared with organic acids , their salt and bentonite. The mould is still growing on feed when the moisture of feed is 14% . The anti-mould agent only with organic acid can deter the growing of mould , but at the moisture of 16% the effect is less, and there was no effect as the moisture were 18%and 20% in feed . The anti-mould agent which supplied potassium sorbate additionally worked more effectively than that contained organic acid only. The result of the test of the anti-mould agent which supplied potassium sorbate additionally to deter mould growing showed that the agent added in feed as level of 0.5% was effective and more economical.The nutriments can be adsorbed by bentonite ,but they can be desorbed mostly ,and the adsorption of toxicants to bentonite was large and stability, so bentonite can be used as detoxify agent in feed and as carrier of anti-mould products.
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