Superovulation in sheep aims to provide hormonal preparations to stimulate growth and ovulation of a higher number of preovulatory follicles. It is a decisive step in ewes multiple ovulation and embryo transfer, although still has results with high variability. Several studies have been performed to obtain a homogeneous and satisfactory answer to this biotechnology, although a better understanding of this phenomena is still required, taking into account the estrous cycle, physiological hormonal regulation and biological phenomenon of follicular dynamics. Considering the importance of superovulation in MOET technique in sheep, this review aims to approach the key aspects of this event in ewes (reproductive physiological phenomena and treatment of superovulation).
The main goal of this study was to assess the usefulness of two imaging modalities, namely the B-mode and colour Doppler sonography, and serum progesterone (P ) concentrations for determining the ovarian response in superovulated ewes. Twenty-four sexually mature Santa Inês ewes underwent the superovulatory treatment consisting of eight injections of porcine FSH (total dose of 200 or 133 or 100 mg; n = 8 ewes/total dose) given at 12-hr intervals and initiated 48 hr before CIDR (Pfizer Inc., Auckland, New Zealand) removal. Six days after natural mating, the ovaries of all donor ewes were visualized and examined with transrectal ultrasonography and then with videolaparoscopy to identify and enumerate corpora lutea (CL) and luteinized unovulated follicles (LUFs). Jugular blood samples were collected just prior to ovarian examinations. The total number of CL (r = .78 and 0.83, p < .0001) and LUFs (r = .74 and 0.90, p < .0001) enumerated using the B-mode and colour Doppler ultrasonographic technique, respectively, were correlated with that ascertained by videolaparoscopy. Circulating concentrations of P were related directly to the number of healthy CL (r = .73, p = .0002) and inversely to the number of prematurely regressing CL (r = -.46, p = .03), but the accuracy of predicting the number of short-lived CL with serum P concentrations was very poor. The present results indicate that ultrasonographic imaging and serum P measurements on the day of embryo recovery are useful indicators of total/normal CL numbers and both ultrasonographic techniques can be used to quantify LUFs in superovulated ewes.
The aim of this study was to evaluate the blood flow of the uterine artery, fetal aorta and umbilical artery in the physiological pregnancy of sheep by means of pulsed Doppler throughout the gestational period. Thirty Santa Inês ewes weighing between 45.4±4.3 kg and aged 2 to 5 years were selected. The evaluations were carried out weekly from the 3 rd to the 21 st gestational week. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI) were obtained. Analysis of variance was performed, and the minimum significant comparison of means was obtained by the BH test with adjusted P<0.05. The results were expressed as mean ± standard error. For the fetal aorta, there was an increase in the EDV values and a decrease in the PSV and RI throughout pregnancy. For the uterine artery, PSV and EDV did not present significant variation, whereas the RI showed a reduction in the last week. Increased EDV values were found for the umbilical artery throughout pregnancy. For the PSV there was no significant difference, as the RI was reduced at the end of pregnancy. The results obtained are expected to contribute to a more complete understanding of the hemodynamic changes resulting from pregnancy.
The objective was to evaluate the blood flow of the uterine artery (UA) and umbilical artery (UMB) in the physiological pregnancy of goats by means of Doppler throughout the gestational period. Twenty-five Saanen goats weighing 55 ± 10 kg and aged between 2 and 5 were evaluated weekly, from the 21 st until the 143 rd day of gestation, and daily from that period until parturition. Values for peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance (RI) and pulsatility (PI) indices of the uterine and umbilical arteries were determined. The values obtained were correlated with gestational age by Spearman's test, tested for adjustment to regression models and compared with the number of fetuses by ANOVA. The umbilical cord was first visualized at 28 days. Of the variables evaluated, RIUMB and PIUMB correlated with gestational age (p<0.001; and 0.046; respectively) and RIUMB had a low negative correlation with the number of fetuses per pregnancy (p = 0.003; r-Spearman = -0.218). PSVUMB and EDVUMB values did not correlate with gestational age (p=0.737 and 0.768, respectively), but there was a decrease in the mean values throughout pregnancy (PSVUMB= 0.07; 0.31 and EDVUMB= 0.01; 0.06) as well as the change in the flow pattern of the spectral trace. The mean values of the uterine artery dopplervelocimetric variables PSVUT, EDVUT, PIUT and RIUT did not correlate with gestational age (p= 0.324; 0.372, 0.143; 0.13; respectively). It is expected that the results obtained will contribute to a broader understanding of the hemodynamic changes resulting from pregnancy in goats.
The aim of this study was to evaluate the applicability of B-mode, Doppler, acoustic radiation force impulse elastography and contrast-enhanced ultrasound exams in the differentiation of neoplastic and non-neoplastic benign mammary lesions in bitches. This research was conducted as a prospective secondary observational cohort (2014–2016) study, which included 36 mammary lesions, evaluated physically and by ultrasound (B-mode, Doppler, contrast-enhanced ultrasound and acoustic radiation force impulse) exams prior to mastectomy and histopathological classification as neoplastic or non-neoplastic lesions. All ultrasonographic parameters studied were compared between histopathological classifications using Fisher’s or Student’s tests and differences were considered significant when P < 0.05. Out of 36 benign mammary lesions evaluated, 25 were classified as neoplastic and 11 as non-neoplastic. The qualitative and quantitative parameters evaluated using the different ultrasound methods were not effective (P > 0.05) in differentiating between neoplastic and non-neoplastic mammary masses in bitches. Nevertheless, some B-mode variables, such as longitudinal length (P = 0.0292), width/length ratio (P = 0.0001) and width/height ratio (P = 0.0001) showed limited efficacy in the differentiation of mammary lesions types. In conclusion, ultrasonographic evaluation of benign canine mammary lesions did not allow differentiation between neoplastic and non-neoplastic tissues and only a few B-mode variables may aid in the prediction of specific tumour types.
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