The invention discloses an organic
selenium-supplementing
feed additive and preparation and a using method thereof. The
feed additive is prepared by the following steps of: adding
chitosan with deacetylation degree of 70 to 100 percent into 0.5 to 2
volume percent of diluted acid with stirring at the temperature of between10 and 60 DEG C to obtain 0.5 to 10 percent acid solution of
chitosan; adding solution of
inorganic selenium into acid solution of
chitosan, wherein the
mass of
inorganic selenium is 1 / 6 to 1 / 2 time that of the chitosan; and reacting for 1 to 12h and separating, washing the obtained
solid matter by using
distilled water for many times until
selenium ions cannot be detected, and
drying and crushing to obtain chitosan
selenium chelate. The chitosan selenium serving as the
feed additive is applied to feeds for
livestock, poultry and aquatic animals and is effectively absorbed and utilized in the animals by using proper stability and
dissolution performance thereof, so that
disease resistance, production performance and meat quality of the animals are obviously improved. The chitosan selenium has the advantages of little
toxicity, high
biological availability, small addition amount, and capability of saving resources and protecting the environment, so that the feed additive is a safe and effective environment-friendly feed additive.