PURPOSE: An apparatus for generating microorganisms in a water container is provided to accelerate the growth of live-stocks by increasing digesting rate based on microorganisms. CONSTITUTION: An apparatus for generating microorganisms in a water container includes an automatic opening/shutting part(17), a heat insulating member, a heater(1), and an air diffuser(2). The automatic opening/shutting part is installed at the upper side of the water container. The heat insulating member surrounds the water container for artificially adjusting the temperature of the water container. The heater and the air diffuser are installed in the water container. A water supplying hole(14) is installed at the sub-layer of the water container. A controlling box(6) is installed at the higher position of water in the water container.본 발명은 비상 급수통안의 맹물 즉 가축들이 마시는 맹물에 막대한 미생물들을 발생시켜서 미생물에 의한 신속한 소화력으로 소화율을 대폭 높여서 가축들이 더 빨리 크면서 더 크게 증체되므로써 사료절감과 동시에 친환경적으로 가축들을 사육하면서 고급육을 생산토록 하는 것이다.