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CHICK SEXING On the Development and Practice of Baby Chick Sexing Method

「CHICK SEXING On the Development and Practise of Baby Chick Sexing Method」

(Donated by Seiichi Saito, the former director of the chick sexing training school of the Japan Livestock Technology Association)

WMV format
MP4 format

This video is a reproduction of a 35 mm film produced by the Japan Chick Sexing Association (J.C.S.A.) for presenting at the 6th World’s Poultry Congress held in Leipzig, Germany in July of 1936. It was discovered in 2005 by Seiichi Sato, the director of the training school at the time, and was reproduced by Dr. Kanjun Hirunagi of the Nagoya University Museum as a VHS video and a DVD because of its excellent state of preservation (1).

Research on sexing newborn chicks based on cloacal protrusions was reported in March 1925 by Dr. Kiyoshi Masui of the College of Agriculture at Tokyo Imperial University and Hashimoto Juro and Isamu Ohno of the Zootechnical Experimental Station of the Agriculture and Forestry Department (2). Until then, male chicks were unnecessarily raised for at least a month until sexing based on external appearances became possible. Therefore, this new technique was a truly revolutionary breakthrough in the poultry industry. Poultry producers made an effort to implement this technique in Aichi Prefecture, which was the largest chicken-producing region at the time, and there were “day-old chicks certified to be 80% female” marketed as early as 1929. Subsequently, many organizations were formed for chick sexing experts, and these various groups unified in October of 1933 to form J.C.S.A. with the mission of spreading the sexing technique and training technicians.

The film was hastily produced after it was determined that Dr. Masui would attend the World’s Poultry Congress. Filming began on June 10, 1936, and was completed two days before his departure on June 21 when a preview screening was held. The upside-down subtitles are evidence of the hurried production process. It was shown on the fifth day of the conference following Dr. Masui’s afternoon presentation and was followed by a demonstration by chick sexing experts.

The first scene to appear in the film is the J.C.S.A. building, which was located across from the Nagoya Municipal Hospital in Mizuhodori, Nagoya City. Shown next is a veterinary classroom in the College of Agriculture at Tokyo Imperial University, where Dr. Masui was training a person referred to as “Koike-kun.” It appears that this was Koichiro Koike, a native of Tokyo, who is listed as a novice sexer at the end of the directory of second-class sexing experts (listed in order of registration) from 1934. Dr. Ryoji Iwazumi of animal science department who appeared in the middle of the film, was the first director of the Japanese Society of Zootechnical Science and was the head of J.C.S.A at the time.

Next, the setting of the film switches to the chick sexing training school, which was newly founded as part of the association in October 1934. This training school established three courses: a basic course (one month), an intermediate course (one month), and an advanced course (three months). The practical skill of restraining the chicks and opening their cloacas was demonstrated by Koji Tamaki using Method A. Method B, proposed by Isamu Ohno, was demonstrated by Mataichi Sakai.

Although not uploaded here, the original version included an introduction to the abdominal section technique, which was proposed by Osamu Kitamura, the director of the association. This was a technique involving a fingertip, without any dissection tools, to open the abdomens of sexed chicks in order to check for ovaries and testes, enabling immediate on-site confirmation of sexing results. This method was used to check for sexing accuracy in licensing examinations and competitions.
In the scene in the classroom, an academic examination was conducted for selecting chick sexing experts to send abroad. The woman in the sailor uniform is Sui Okutomi from Saitama Prefecture. Sui was active in the UK in 1937 and was the first female chick sexing expert sent overseas. The examination proctor in Japanese clothing is Manabu Kojima, who aimed for practical implementation of the technique. Tomiichi Furuhashi was a world record holder and major veteran who was sent to the UK in 1935, Australia in 1936, and Belgium in 1937. His record of sexing 100 chicks in 5 minutes and 45 seconds with 100% accuracy was set at the J.C.S.A 500 Chick Sexing Contest in 1936.

In the incubation room, hatching eggs were removed and their temperatures were measured. A thermometer/hygrometer was attached to the wall; however, checking the temperature of eggs by placing them against the eyelid is a universal technique that has been used for a long time.

Appearing last is Sanwa Farm. This was a feed testing site for Ito Shoji, a poultry feed company that raised 80,000 chickens on a large property of about 13 hectares in Ohdaka-cho, Midori-ku, Nagoya City, which was the largest in the Oriental hemisphere at the time. “Milk-fed chickens” are those that were raised using a feed containing whole milk and powdered skim milk, which was said to have had a tremendous effect on their growth.

Dr. Masui passed away in 1981 but was inducted into the International Poultry Hall of Fame at the 18th World’s Poultry Congress, held in Nagoya in 1988. The World’s Poultry Congress is held every four years, so this film was shown to much acclaim at the 100th Anniversary Congress held in Brazil in August 2012. At this event, Dr. Kiyoshi Shimada of Nagoya University became the long-awaited second Japanese inductee to the International Poultry Hall of Fame.


Makoto Mori, Professor Emeritus in Shizuoka University


(1) Hirunagi K. Original film of “CHICK SEXING On the Development and Practice of Baby Chick Sexing Method” was found. Bulletin of the Nagoya University Museum, 22: 65-72. 2006. (in Japanese with English abstract)

(2) Masui K, Hashimoto J and Ono I. The rudimental copulatory organ of the male domestic fowl, with reference to the difference of the sexes in the chick. Animal Science Journal, 1:153-163. 1925. (in Japanese with English summary)