PROBLEM TO BE SOLVED: To provide an automatically death rate-judging method for automatically judging the death rate of chickens from an image obtained by photographing the many chickens which are reared, and an automatically death rate-judging device, which enable the accurate automatic correction of errors caused by the rate of day-old growth and the photographing of overlapped chickens on an image in response to a current state, the real time presentation of the death rate of broilers, and the highly accurate automatic expression of warning, when the death rate exceeds a risk rate. SOLUTION: This automatically death rate-judging method has a step for photographing many chickens with a thermograph to obtain an image, a step for calculating a total chicken area corresponding to pixel at a prescribed temperature or higher on the basis of the obtained image, a step for calculating a present day-old permissible surface area from a chicken present day-old standard surface area taken from a table, the last calculated total chicken number, and a risk death rate, and a step for judging that a death rate is large, when the calculated total area is smaller than the calculated permissible surface area. COPYRIGHT: (C)2006,JPO&NCIPI
