Pregnancy diagnosis, fetal quantification and gender estimation by ultra-sonography in ewes

Abstract

The objective of this experiment was to evaluate the accuracy of gestation, fetal sexing and quantification diagnoses in ewes. Pregnancy and fetal quantification were diagnosed in 105 ewes at 35 days of pregnancy. For the fetal gender diagnosis sexing diagnose 55 ewes between 49 and 59 days of pregnancy were used. All exams were recorded on DVD for posterior analysis. After birth, lamb sex was recorded to determine fetal sexing precision. Data were analyzed by chisquare ( 2 ) or Fisher's test, with a significance of 0.05. One hundred percent of pregnancy ultrasound diagnoses were correct. As for the fetal quantification diagnoses, there was an error of 12%. It was possible to diagnose the fetal sex in 87% of the 69 examined fetuses, and 90% of these were estimated correctly. The realtime ultrasound diagnoses were not different from the recorded DVD image diagnoses. Therefore, pregnancy diagnosis accuracy may reach 100%, differing from fetal gender estimation and quantification, which are dependent upon other variables such as fetal gender and examiner experience.Index terms: Ovine, fetal sexing, pregnancy diagnosis, ultra-sonography. RESUMOO objetivo deste experimento foi avaliar a acurácia do diagnóstico de gestação, quantificação e sexagem fetal em ovelhas. Foram realizados o diagnóstico de gestação e a quantificação fetal em 105 ovelhas aos 35 dias de gestação. Para o diagnóstico da sexagem fetal foram utilizadas 55 ovelhas com período de gestação entre 49 e 59 dias. As imagens de todos os exames foram gravadas em DVD para permitir posterior análise. Após o nascimento dos cordeiros, os respectivos sexos foram observados para determinar a precisão do exame de sexagem fetal. Os dados foram analisados pelo teste Qui-quadrado ( 2 ) ou Teste de Fisher, com nível de significância de 5%. Observou-se 100% de acerto no diagnóstico de gestação pela ultra-sonografia. Quanto ao diagnóstico de quantificação fetal, houve 12% de erro. Foi possível diagnosticar o sexo fetal em 87% dos fetos e destes, 90% estavam corretos. Os diagnósticos em tempo real não foram significativamente diferentes dos diagnósticos feitos após a observação de imagens gravadas em DVD. Portanto, a acurácia do diagnóstico de gestação pode alcançar 100%, diferente da quantificação e sexagem fetal, que dependem de outras variáveis como tipo de gestação e experiência do operador. Termos para indexação:Ovinos, sexagem fetal, diagnóstico de gestação, ultra-sonografia.

Fetal sexing in small ruminants through visualization of the genital tubercle

“…However, sexing of female fetuses was more efficient in both evaluated periods (Table 6). This is contrary to the results obtained by Coubrough & Castell (1998) and Dias et al (2009), who reported higher efficiency in the diagnosis of male fetuses. Dias et al (2009) attributed the difference to the difficulty associated with the visualization of the GT when it was located near the tail, possibly due to poor fetal position and thus not allowing good images of the pelvic region.…”

“…Of the 50 fetuses born, three were not diagnosed for fetal quantification on day 55 of gestation; however, on day 65, only one fetus was not diagnosed, these fetuses were from double gestations mistakenly diagnosed as single gestations. In this study, in accordance with the findings by Dias et al (2009), the accuracy of fetal quantification in single gestations was higher than in double gestations (Table 8). Depending on the period and type of gestation, it is not always possible to quantify or determine the sex of all fetuses in small ruminants.…”

“…A goat with quadruple gestation was mistakenly diagnosed as a double gestation during the two evaluated periods. The inaccuracy was verified only at delivery, which commonly occurs in multiple gestation, as noted by Dias et al (2009) who also reported errors in fetal quantification, especially in the case of multiple gestation.…”

“…This observation corroborates the points raised by Santos et al (2007b). According to Dias et al (2009), the female's tolerance to the examination is a factor that can lead to errors in the quantification and determination of fetal sex. In the present study, during the evaluations, it was observed that some animals were less tolerant to the test, being restless and making the diagnosis more difficult.…”

Efeito da administração de hCG para indução de ovulação e estudo da dinâmica folicular no protocolo de nove dias de sincronização de estros em ovelhas Santa Inês

“…Em ovelhas, o período para a completa de involução uterina é de aproximadamente 32 dias, mas pode variar de acordo com a raça e estação (HAYDER; ALI, 2008). (DIAS et al, 2009), mas especialmente no que se refere à dinâmica folicular, existe a necessidade de um bom treinamento, pois a anatomia da espécie dificulta o exame, limitando apenas a entrada do transdutor no reto da ovelha, sem o auxílio das mãos para direcioná-lo próximo aos ovários.…”