Patent ID: 7514111

Claim:
A method for preparing a granular animal feed additive, which comprises: filtering, with a membrane filter, a fermentation broth obtained from a lysine producing microorganism cultured in a lysine producing condition to obtain a lysine-containing filtrate and a microorganism-containing sludge; drying the filtrate to obtain a concentrate with a total solid content of 48 to 52 wt %; granule-drying the concentrate at a temperature of 50° C. to 60° C. to obtain granules; and coating the granules with a coating agent containing a lysine content adjuster and one or more additives selected from the group consisting of the sludge, and a moisture prevention agent, wherein the lysine content adjuster is a diluent or free lysine depending on the lysine content of the granule, to obtain lysine granules having the following properties: Lysine content (lysine sulfate) 65% or more Grain size 300–1,200 μm, 90% or more Apparent density 620–720 kg/m 3 Protein content 10–15% Total sugar content >0–1% Inorganic material content >0–3% Water content >0–3% Carboxylic acid content >0–8% SO 4 − ion content 20–25% and wherein the animal feed additive has a constant content of lysine.