225 Evaluation of superovulatory response in Brazilian native sheep by B-mode ultrasonography
G. B. Vergani A , M. S. D. Lima B , K. M. Silva C , A. W. U. Monteiro C , A. F. Ramos D , R. I. T. P. Batista E , W. R. R. Vicente A , M. E. F. Oliveira A and J. F. Fonseca CA School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, Brazil;
B Ceará State University (UECE), Fortaleza, CE, Brazil;
C Embrapa Goats and Sheep, Sobral, CE, Brazil;
D Embrapa Genetic Resources and Bioecology, Brasília, DF, Brazil;
E Federal University of Vale do Jequitinhonha and Mucuri, Diamantina, MG, Brazil
Reproduction, Fertility and Development 32(2) 240-241 https://doi.org/10.1071/RDv32n2Ab225
Published: 2 December 2019
Abstract
The objective of this study was to evaluate the correlation between the number of corpora lutea (CL), as determined by B-mode ultrasonography, and the total number of structures recovery by non-surgical embryo recovery (NSER) from superovulated ewes. Somali (n = 18), Santa Inês (n = 18), and Morada Nova (n = 16) ewes received an intravaginal device with progesterone (0.33 g, controlled internal drug release device, CIDR, Zoetis), which was maintained for 9 days. The superovulatory protocol started 60 h before device removal, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) of p-FSH (IM 133 mg, Folltropin V, Vetoquinol) injected every 12 h. D-Cloprostenol (IM 37.5 μg, Prolise, Agener Union) was injected 12 h before and at the moment of device removal. Ewes in oestrus were mated by fertile male rams three times after the onset of oestrus with a 12-h interval. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was injected IM on Days 12, 13, and 15. One day before NSER, B-mode ultrasound evaluations were performed using portable equipment (Z5 Vet, Mindray) with a stiffened multifrequency linear probe to evaluate the number of structures present in the ovaries. Embryo recovery was performed 7 days after progesterone CIDR removal (Day 16). The number of CL and the number of recovered structures were determined and their association evaluated using the Pearson correlation test (P < 0.05). Only 17 Somali, 16 Santa Inês, and 15 Morada Nova ewes were submitted to NSER; the other 4 ewes could not be flushed because of low cervical dilation or cervical puncture. After B-mode ultrasound evaluation, 168, 217, and 131 CL were observed, with an average of 9.9 (range: 1 to 12), 13.5 (range: 2 to 47), and 8.7 (range: 3 to 18) CL per donor for Somali, Santa Inês, and Morada Nova ewes, respectively. The recovery rates (i.e. structures recovered by the number of CL counted) were 60.1% (101/168), 96.3% (209/217), and 103.5% (135/131) for the 3 breeds, respectively. There was a positive correlation (r = 0.69; P < 0.01) between the number of recovered structures and number of CL. Those findings confirm results from other studies, in which the recovery rate varied from 35 to 91%. In some cases, recovery rate can be overestimated because of the difficulty in quantifying CL. In conclusion, B-mode ultrasonography can be used to estimate superovulatory response in ewes and thus as a criterion to decide whether a donor will undergo embryo flushing.
Financial support for this study was provided by Embrapa (02.13.06.026.00.04) and Fapemig (CVZ-PPM 00201-17).
