03361nam a2200361 a 450000100080000000500110000800800410001910000230006024501750008326000710025850001300032952021850045965000090264465000140265365000170266765000170268465000100270165000140271165000140272565000110273965000100275065000170276065000240277765300250280170000180282670000210284470000270286570000180289270000240291070000210293470000220295570000220297720742582022-05-17       2017    bl uuuu     u00u1 u    #d1 aOLIVEIRA, M. E. F.  aDynamic of synchronized follicular wave in ewes subjected to different doses of 17b-oestradiol given at the beginning of the progesterone protocol.h[electronic resource]  aReproduction, Fertility and Development, v. 29, n. 1, p. 118c2017  aProceedings of the 43rd Annual Conference of the International Embryo Technology Society, Austin, Texas, 14-17, January 2017.  aAbstract: This study was designed to evaluate the effect of different doses of 17beta-oestradiol injection at the beginning of the progesterone protocol on follicular wave dynamic in ewes. In a random day of the oestrous cycle (D0), twenty-four Santa Ines ewes received an intravaginal progesterone device (CIDR®) and a injection of 17beta-oestradiol (E2, Sincrodiol®, Ourofino, Brazil) in different doses (350, 500, and 1000 µg) for G-350E2, G-500E2, and G-1000E2, respectively (n = 8 per group). Ultrasound examinations were performed daily during the CIDR permanence (10 days) using MyLab 30Vet equipment (Esaote, Italy) connected to transrectal linear transducer (frequency of 7.5 MHz). Follicular wave was defined as a follicle or a group of follicles 2 to 3 mm in diameter that grew to 4.5 mm in size before regression or ovulation. The day of wave emergence was based on the day on which the largest follicle of a wave was first detected at 2 or 3?mm (retrospective analysis). Data were analysed by ANOVA followed by a Tukey test (mean ± SEM; P &lt 0.05) using SAS software. The emergence of a new follicular wave after the beginning of protocols was not detected in 8 out of 24 ewes (33.3%), being 3 from G-350E2, 2 from G-500E2, and 3 from G-1000E2. There was difference (abP = 0.04) for follicular wave emergence day (3.00?±?0.32b, 4.00?±?0.45ab and 5.20?±?0.73a) and averaged day of maximal follicle diameter (8.20 ± 0.58b, 9.50 ± 0.34ab and 9.80 ± 0.20a) for G-350E2, G-500E2 , and G-1000E2, respectively. However, the growing period and the maximum diameter of the largest follicle of this wave did not differ between groups (124.80?±?8.98?h and 5.42 ± 0.25 mm for G-350E2; 132.00 ± 5.37 h and 5.75 ± 0.23 mm for G-500E2; and 110.40 ± 16.28 h and 5.20 ± 0.73 mm for G-1000E2, respectively). In conclusion, the 17beta-oestradiol injection at the beginning of the progesterone protocol was not able to induce the emergence of a new follicular wave in all of females, regardless of dose. However, the synchronized follicular wave occurred earlier in females treated with the lowest dose of the 17beta-oestradiol than those that received the highest dose.  aEwes  aInjection  aProgesterone  aReproduction  aSheep  aEstradiol  aInjeção  aOvelha  aOvino  aProgesterona  aReprodução animal  aSynchronized females1 aNOCITI, R. P.1 aCAMELA, E. S. C.1 aPADILHA-NAKAGHI, L. C.1 aMACIEL, G. S.1 aRODRIGUEZ, M. G. K.1 aSANTOS, V. J. C.1 aFONSECA, J. F. da1 aVICENTE, W. R. R.