ABSTRACT
The objective of this study was to identify the migration period of the genital tubercle and the period of visualization of external genital structures in fetuses of the Dorper breed of sheep derived from natural mating and from fresh, frozen and vitrified embryo transfer. Transrectal ultrasound was performed using a double-frequency linear transducer (6.0 and 8.0 MHz) to monitor 130 ewe fetuses distributed in the four treatments regarding embryo origin. The accuracy of the ultrasound was 100% in this experiment. The fetuses originated from controlled natural mating (NM) and from fresh (FrE), frozen (FE) and vitrified (VE) embryo transfer, with embryos collected 7 days after breeding. Migration of the genital tubercle occurred earlier (P<0.05) in NM (42.21+/-2.86 days) than in FrE (43.98+/-3.00 days), FE (44.97+/-1.83 days) and VE (44.58+/-1.97 days). Visualization of the scrotal bag, prepuce and vulva occurred, respectively, earlier (P<0.05) in NM (45.22+/-1.25, 45.95+/-1.53 and 45.01+/-1.03 days) than in FrE (48.91+/-1.92, 48.52+/-1.41 and 47.41+/-1.41 days), FE (49.97+/-1.08, 49.18+/-2.00 and 47.64+/-1.82 days) and VE (50.12+/-1.66, 49.27+/-1.61 and 47.93+/-1.92 days). The results show that fetal sexing can be accomplished from the 50th day onward in fetuses produced by natural mating and from the 55th day onward in fetuses derived from fresh, frozen and vitrified embryos. It can also be concluded that real-time ultrasonography is a reliable tool for fetal sex determination in sheep taking into account both the location of the genital tubercle and the identification of external genital structures.
Subject(s)
Cloning, Organism/methods , Embryo Transfer/methods , Embryo Transfer/veterinary , Sex Determination Analysis/methods , Sheep, Domestic/embryology , Ultrasonography, Prenatal/methods , Ultrasonography, Prenatal/veterinary , Animals , Female , Pregnancy , Pregnancy, Animal , Reproducibility of Results , Reproductive Techniques, Assisted , Sheep , Ultrasonography/methodsABSTRACT
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.
Subject(s)
Genitalia, Female/embryology , Genitalia, Male/embryology , Goats/embryology , Sex Determination Analysis/veterinary , Sheep/embryology , Animals , Female , Genitalia, Female/diagnostic imaging , Genitalia, Male/diagnostic imaging , Male , Pregnancy , UltrasonographyABSTRACT
OBJECTIVE: To define the optimum period for sexing of Saanen goat fetuses by use of transrectal ultrasonography. ANIMALS: 82 Saanen goats pregnant with 124 fetuses. PROCEDURES: Fetal sexing was performed on the basis of the final location of the genital tubercle or identification of external genitalia. In experiment 1, fetuses (n = 78) were monitored every 48 hours from days 40 to 60 of gestation, whereas for experiment 2, 46 fetuses were examined only once between days 47 and 77 of gestation. RESULTS: For experiment 1, accuracy of fetal sexing was 20 of 20 (100%) for a single fetus, 39 of 42 (92.8%) for twin fetuses, and 10 of 16 (62.5%) for triplet fetuses. Diagnostic accuracy was significantly lower for triplet fetuses than that for single or twin fetuses. Final location of the genital tubercle was detected between 45 and 55 days of gestation (mean +/- SEM, 48.9 +/- 1.8 days). For experiment 2, accuracy of fetal sexing for a single fetus (24/24 [100%]) was significantly higher than the accuracy for twin fetuses (16/22 [72.7%]). Considering all fetuses that were born, accuracy of diagnosis was 69 of 78 (88.4%) for experiment 1 and 40 of 46 (86.9%) for experiment 2. Accuracy did not differ significantly between experiments. CONCLUSIONS AND CLINICAL RELEVANCE: Real-time ultrasonography after day 55 of gestation is a suitable method for determination of sex of Saanen goat fetuses by observation of the genital tubercle or identification of external genitalia.
Subject(s)
Genitalia/diagnostic imaging , Genitalia/embryology , Goats/embryology , Sex Determination Analysis/veterinary , Ultrasonography, Prenatal/veterinary , Animals , Female , Fetal Development , Male , Pregnancy , Sex Determination Analysis/methodsABSTRACT
O presente estudo teve a finalidade de identificar o sexo e de determinar o dia da migração do tubérculo genital (TG) de fetos ovinos através da ultra-sonografia em tempo real. O sexo foi identificado no Experimento I (EI) levando-se em consideração a localização do TG e no Experimento II (EII), a presença do pênis, prepúcio e bolsa escrotal no feto macho e das tetas, vulva e clitóris no feto fêmea. No EI, as fêmeas (n=17) foram monitoradas em intervalos de 12 horas, do 35o ao 46o dia de gestação, por via transretal com transdutor linear (6,0 e 8,0 MHz). No EII, as fêmeas (n=30) com gestação de 55 a 75 dias foram examinadas apenas uma vez, utilizando-se o mesmo transdutor e via de exame do EI. Das 17 fêmeas do EI, 11 (64,6 por cento) tiveram seus fetos corretamente sexados, independente da gestação ter sido simples (7/11), dupla (3/11) ou tríplice (1/11). Nas 6 (35,4 por cento) gestações restantes, 3 (17,7 por cento) foram duplas, sendo impossível sexar um feto de cada gestação. Nas outras 3 (17,7 por cento) gestações, os fetos foram corretamente sexados, apesar dos nascimentos não coincidirem com a quantificação. Num feto macho de uma gestação simples, a migração ocorreu no 37º dia e até o 46º, todos os fetos das outras gestações estavam corretamente sexados. Das 30 fêmeas do EII, 16 (53,4 por cento) apresentaram gestações simples e a acurácia da sexagem foi de 100 por cento. Nas 14 (46,6 por cento) restantes, as gestações foram duplas, sendo impossível, em quatro casos, determinar o sexo de, pelo menos, um dos gêmeos. De todos os fetos nascidos, a acurácia geral da sexagem foi de 88,0 por cento (EI) e 90,9 por cento (EII), não sendo observada diferença (P>0,05) entre ambos os experimentos. Os resultados permitem concluir que a ultra-sonografia em tempo real é um método eficiente para diagnosticar o sexo fetal pela visualização do TG, assim como pela identificação do pênis, prepúcio e bolsa escrotal no feto macho e das tetas, vulva e clitóris no feto fêmea, desde que os exames sejam realizados a partir do 50o dia de gestação.
