F. Q. G. Bezerra

Sexagem fetal em ovelhas Santa Inês por ultra-sonografia

The present study aimed to identify the sex and to determine the day of genital tubercle (GT) migration of ovine fetuses using real time ultrasonography. The sex was identified in Experiment (EI) taking into consideration the localization of GT and in Experiment II (EII) the presence of penis, prepuce and scrotal bag in male fetus and nipples, genital swelling and clitoris in female fetus. In EI, the females (n=17) were monitored with 12 hour intervals from the 35th to the 46th day of pregnancy, by transrectal via with linear transducer (6.0 and 8.0MHz). In EII, the females (n=30) with pregnancy period from 55 to 75 days were examined once only, using the same transducer and via used in EI. Among 17 females in EI, 11 (64.6%) fetuses were correctly sexed independent of single (7/11), twin (3/11) or triple (1/11) pregnancy In 6 (35.4%) pregnancies, 3 (17.7%) were twins, being impossible to sex one fetus of each pregnancy. In other 3 (17.7%) pregnancies the fetuses were correctly sexed, although the birth did not coincide with the quantification. In a male fetus of a single pregnancy, the migration of the GT began on day 37 of pregnancy and on the 46th day all the fetuses of the other pregnancies were correctly sexed. Among 30 females in EII, 16 (53.4%) pregnancies were single being sexed with accuracy of 100%. In other 14 (46.6%) remainder the pregnancies were twins, being impossible, in four cases, to be determined the sex of one of each twin. The incorrect diagnoses were fetuses sexed as females, however born as males. From the all born fetuses the total accuracy was 88.0% (EI) and 90.9% (EII), being not observed difference (P>0.05) between both experiments. The results allow to conclude that ultrasonography in real time is an efficient method to diagnose the fetal sex by visualization of GT, as well as by identification of penis, prepuce and scrotal bag in male fetus and nipples, genital swelling and clitoris in female fetus, since the scanning are performed from Day 50 of pregnancy

Migration time of the genital tubercle in caprine and ovine fetuses: Comparison between breeds, sexes and species

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.

Sexing of Dorper sheep fetuses derived from natural mating and embryo transfer by ultrasonography

In order to improve fetal sexing in the Dorper sheep breed, the objective of the present study was to determine, by repeated ultrasonographic examinations, the migration period of the genital tubercle (GT) in sheep fetuses derived from natural mating or embryo transfer and to compare the accuracy of a single examination with repeated examinations at short intervals. For this purpose, transrectal ultrasound was performed, using a double-frequency linear transducer (6.0 and 8.0 MHz) for monitoring 51 sheep fetuses distributed in three experimental groups (EI, EII and EIII). The fetuses in EI (n = 23) and EII (n = 18) derived, respectively, from natural mating and embryo transfer were monitored at 48-h intervals from the 30th to 60th day of gestation and sexed based on the final location of the GT. The fetuses in EIII (n = 10), which originated from embryo transfer, were examined only once on the 65th day of gestation and sexed taking into consideration the final position of the GT and/or by identification of anatomical structures of external genitalia. The accuracy of fetal sexing was 91.3% (21 fetuses sexed/23 quantified) in EI, 88.9% (16 sexed/18 quantified) in EII and 100% (10 sexed/10 quantified) in EIII, without significant difference (P > 0.05) between experiments. Migration of the GT occurred earlier (P < 0.05) in fetuses produced by natural mating (43.0 +/- 2.8 days) than in those derived from embryo transfer (46.1 +/- 4.7 days). The results show that fetal sexing can be done from the 50th day onward in fetuses produced by natural mating and from the 60th day onward in fetuses derived from frozen embryos. It can also be concluded that repeated ultrasonographic exams in short time intervals do not maximise the accuracy of fetal sexing. In addition, real-time ultrasonography is a reliable tool for fetal sex determination in sheep after Day 50 of gestation, taking into account both the location of the GT and the identification of external genital structures.

Early fetal sexing of Saanen goats by use of transrectal ultrasonography to identify the genital tubercle and external genitalia

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.