According to the present invention, as an insoluble component such as protein, hemicellulose, and cellulose exists in a byproduct generated during a food processing process, when the byproduct is directly supplied to livestock feed, most of nutrient sources is not absorbed and is excreted from the body. To solve the problem described above, present invention provides an additive for livestock feed which is obtained by stabilizing sludge (a byproduct) generated during a food processing process through performing a fermentation process using a microbial fermentation liquid obtained from a natural plant in a special process, and by mixing the sludge with conventional feed components. According to the present invention, the livestock feed in the present invention is provided by: a first step for obtaining a base mixed raw material by mixing 50-80 parts by weight of a feed raw material component selected from rice bran or corn bran with 20-50 parts by weight of a byproduct generated during a bean processed food producing process a second step for adding 10-50 parts by weight of a microbial fermentation liquid to 100 parts by weight of the base mixed raw material obtained in the first step, and fermenting for 12-48 hours and a third step for drying the fermented product obtained through the second step to have a moisture content in the range of 5-7 wt% via a screen, and packaging the dried product. Therefore, the additive for livestock which does not deteriorate after being commercialized as feed is provided.COPYRIGHT KIPO 2016본원은 식품가공 과정 중 발생되는 부산물은 단백질과 헤미셀룰로즈, 셀룰로즈와 같은 불용화 성분도 존재하므로 직접 가축사료로 공급되는 경우 그 영양원은 대부분 흡수되지 못하고 체외로 배설되는 문제점을 해소하기 위한 수단으로 본원은 특수 공정으로 천연식물로부터 얻는 미생물발효액을 이용하여 식품가공 과정 중 발생되는 슬러지(부산물)에 발효공정을 수행하여 안정화시킨 후 기존의 사료성분과 혼합하여 가축사료용 첨가제를 얻고자 하는 발명이다.본원에서 제공되는 가축사료는 미강이나 옥수수겨 중에서 선택되는 사료원료 성분 50~80 중량부와 콩 가공식품 제조과정 중 발생되는 부산물 20~50 중량부가 혼합되어 기본혼합원료를 얻는 제1단계와 상기 제1단계에서 얻은 기본혼합원료 100 중량부에 미생물발효액 10~50 중량부를 넣고 12~48시간 범위로 발효시키는 제2단계와 상기 제2단계를 거쳐 얻은 발효물을 스크린을
