title: A novel method for sexing day-old chicks using endoscope system.
abstract: Sexing day-old chicks is important for layer and broiler production. A novel method for sexing day-old chicks was developed using an endoscope system. The probe of the endoscope was inserted from the cloaca into the intestine of a chick, and the presence of testes or ovary was observed through the wall of the intestine. The picture image was displayed on the monitor. Sexing was performed in White Leghorn (WL) and Rhode Island Red (RIR) chicks using this new system. The accuracy of sexing was 91.1% in WL chicks and 88.3% in RIR chicks, confirmed by observing gonads after laparotomy or appearances at 80 d of age. Accuracy of sexing male chicks (95.0%) was higher than that of female chicks (86.0%). The overall accuracy of sexing was 90.2% in the present study, and the accuracy would be improved by continuous training in the handling of the endoscope. The endoscope system devised in this study requires no specific skills and anyone can perform sexing of chicks after short-term training.
authors.affiliation: NARO Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Otsuka
authors.affiliation: NARO Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyashita
authors.affiliation: NARO Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shibata
authors.affiliation: NARO Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Fujiyuki
authors.initials: F
authors.lastname: Sato
authors.affiliation: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan mnaito@affrc.go.jp.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Naito
mesh_terms: D000818:Animals; D002645:Chickens; D002988:Cloaca / Q000000981:diagnostic imaging; D004724:Endoscopy / Q000295:instrumentation / Q000662:veterinary*; D005260:Female; D006066:Gonads / Q000000981:diagnostic imaging*; D008297:Male; D012732:Sex Determination Analysis / Q000295:instrumentation / Q000662:veterinary*
keywords: PCR; day-old chick; endoscope; gonad; sexing