Professor Kiyoshi Masui was born in Shizuoka, Japan, in 1887 and died in 1981. He completed the Veterinary Science course at Tokyo University, graduating in 1915 and went on to obtain his PhD in Veterinary Science in 1921.
Following appointment as an assistant Professor in the University of Tokyo in 1922, most of his pioneering work on the domestic fowl was conducted there. He retired as a full Professor in 1948, being made Professor Emeritus a few months later.
In 1951, Dr Masui was appointed a Professor of Nagoya University and Dean of the Faculty of Agriculture, posts which he held until his retirement form Nagoya in 1958. He then, at 73, became Director of the Masui Poultry Institute which was established to undertake research into animal genetics, especially in the case of the domestic fowl, the genetics of sex determination and differentiation.
Dr Masui's contribution to the world poultry industry is the development of the sexing technique of day-old chicks based on his fundamental studies of sexual differentiation in the fowl. In his anatomical studies on the genital organs of the domestic fowl, he found a small rudimental copulatory organ in the cloaca of male chicks, and in 1925 he reported the possibility of sex determination of day-old chicks by checking the presence or absence of this organ by the naked eye.
He conducted the basic studies on sex differentiation of chicks and finally established a perfect sex determination method for newly hatched chicks. His method was presented at the 3rd and 6th World Poultry Congress in 1927 and 1936 respectively. Chick sexing was demonstrated at the 5th World Poultry Congress in 1933. His works on sex determination and sexual differentiation in the fowl were published by the University of Tokyo Press in 1967.
Dr Masui made a great effort to propagate the sexing technique all over the world. He founded the Japanese Chick Sexer's Association - an organization that trained many professional chick sexers and sent only those who were qualified to North and South America, Europe and Australia. The method, now adopted by virtually all the hatcheries in the world, is due to these Japanese sexing experts who had learned Dr Masui's method. In turn this has contributed to a reduction in feed and labour requirements and costs in the modern poultry industry.
Nominated by Japan