Some are effective only with certain breeds or crosses, while others are universal. The two chief methods of sexing chicks are feather sexing and vent sexing. Play media Vent sexing in Wenchang , Hainan, China Vent sexing, also known simply as venting, involves squeezing the feces out of the chick, which opens up the chick's anal vent called a cloaca slightly, allowing the chicken sexer to see if the chick has a small "bump", which would indicate that the chick is a male.
Some females also have bumps, though they are rarely as large as those of male chicks. Most males have a relatively prominent eminence, most females have none. However, a small proportion of both males and female have relatively small eminences. Sexing these chickens can be quite difficult, but with regular practice, the sexer will eventually learn to identify the differences. When learning to sex chickens, it is best to assume that chickens with small eminences are female.
The male eminence is solid and will not disappear upon gentle rubbing with one's thumb. A paper about vent sexing was published in Japan in by Professors Masui and Hashimoto, which was soon translated into English under the title sexing baby chicks. After their discovery, interested poultry breeders hired those who had been trained in Masui and Hashimoto's technique, or sent representatives to Japan to learn it.
The sex-linked slow-feathering gene can be used for crosses where the sex of the chicks can be determined at hatching time by the length of the wing feathers. A cross between a fast-feathering male and a slow-feathering female results in offspring where the female chicks have primary wing feathers that are significantly longer than the coverts. The male chicks have primary wing feathers that are shorter, about the same length as the coverts.
An S female mated to an s male will produce offspring where the females have a darker, buff down color, while the males have a lighter, whiter down colour. If not obscured by other coloration controlled by other genes , the chicks can accurately be sexed with little or no training. With Barred Rocks, the males tend to have a large, distinct white head spot and yellow feet, and the females have a smaller, less well-defined head spot and darker feet.
With all these breeds, the chicks with the most distinct indicators can be sexed with confidence, while the others cannot. Nevertheless, one can often pick over a straight-run batch of chicks at a feed store, say and find enough of the desired sex.
At that time, their secondary sex characteristics begin to appear, making it possible for anyone with a minimal amount of training to sex a chicken.
In-ovo sexing[ edit ] Automated systems to determine the gender of the developing chick long before hatching have been announced but not widely deployed as of July The Keeler Optical English or Chicktester Japanese machine features a blunt-ended telescopic tube, containing a light.
The sexer inserts the tube into the evacuated cloaca and with the help of the light can identify either testis or ovaries. Successful development of this technique depends on the capability of the students and their level of experience.