Laying hen compound biological feed additive and preparation method thereof

The invention provides laying hen compound biological feed additive, and belongs to the technical field of feed science and feed additives. The feed additive is compoundly prepared by feed grade fluvic acid, worm powder, fermented frass, an extractive compound preparation, a microecologic preparation and carriers by a certain ratio. Premix of the compound biological feed additive is used in the feed of a laying hen. Environment in the digestive tract of livestock and poultry can be regulated and controlled, intestinal flora balance in an organism can be regulated, the organism immunity can be improved, and the feed additive has the properties of being antimicrobial and anti-stress, and improving immunity and production. The feed additive is added into daily ration of the laying hen to improve the laying capacity and the immunity of the laying hen, improve the feed conversion rate, and then to reduce drug residue and improve egg quality. The compound biological feed additive is a safe and reliable and green environmental protection feed additive product, and the application prospect is good.