title: Migration time of the genital tubercle in caprine and ovine fetuses: comparison between breeds, sexes and species.
abstract: The aim of this work was to determine the ideal moment to sex goat and sheep fetuses, to compare the average time of genital tubercle (GT) migration between sexes, breeds and species, and to evaluate the accuracy of fetal sexing between sexes. A total of 317 fetuses of 219 pregnant females were monitored at 24-hour interval, from days 30 to 60 of pregnancy in ewes, and from days 40 to 60 in goats. Examinations were performed using transrectal ultrasound equipped with a linear transducer of double frequency. Fetuses were identified as male when the GT was next to the umbilical cord and female when the GT was next to the tail. The average time of GT migration in ewes (41.3 +/- 3.1 days) was shorter (P < 0.05) than in goats (47.2 +/- 2.3 days)? In goats, the average time of GT migration of Saanen fetuses was later (P < 0.05) than in fetuses of other breeds, with no difference in the average time of GT migration between male (46.9 +/- 2.2) and female fetuses (47.4 +/- 2.4). In ewes, the average time of GT migration did not differ (P > 0.05) among breeds and sexes. In goat and sheep, no difference was noticed in the accuracy of fetal sexing between males and females (P > 0.05). The results show that fetal sexing in ewes must be done earlier than in goats, fetal sexing in Saanen goats must be performed later, and fetal sex does not influence the time of GT migration in either of the two species.
authors.affiliation: Laboratory of Reproduction Biotechnology, Department of Veterinary Medicine of Federal Rural University of Pernambuco, Av. Dom Manoel de Medeiros s/n, Dois Irmiõs, CEP 52171 900 Recife, Pernambuco, Brazil.
authors.forename: Elielete Maria Pires
authors.initials: EM
authors.lastname: Azevedo
authors.forename: Maico Henrique Barbosa
authors.initials: MH
authors.lastname: dos Santos
authors.forename: Cristiano Rocha Aguiar
authors.initials: CR
authors.lastname: Filho
authors.forename: Leopoldo Mayer
authors.initials: LM
authors.lastname: Freitas Neto
authors.forename: Filipe Queirós Gondim
authors.initials: FQ
authors.lastname: Bezerra
authors.forename: Jairo Pereira
authors.initials: JP
authors.lastname: Neves
authors.forename: Paulo Fernandes
authors.initials: PF
authors.lastname: Lima
authors.forename: Marcos Antônio Lemos
authors.initials: MA
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D005260:Female; D005836:Genitalia, Female / Q000000981:diagnostic imaging / Q000196:embryology*; D005837:Genitalia, Male / Q000000981:diagnostic imaging / Q000196:embryology*; D006041:Goats / Q000196:embryology*; D008297:Male; D011247:Pregnancy; D012732:Sex Determination Analysis / Q000662:veterinary*; D012756:Sheep / Q000196:embryology*; D014463:Ultrasonography