Banca de DEFESA: ALINE MATOS ARRAIS
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : ALINE MATOS ARRAIS
DATE: 28/06/2021
TIME: 13:00
LOCAL: Encontro remoto via plataforma Google Meet
TITLE:
Production and recovery of embryos by non-surgical method in Morada Nova ewes.
KEY WORDS:
Superovulation, cervix, progesterone, sheep, germplasm banks.
PAGES: 74
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Reprodução Animal
SPECIALTY: Inseminação Artificial Animal
SUMMARY:
The objective of the present study was to enable the production and collection of embryos by the non-surgical method (NSER) in Morada Nova ewes, since the use of this procedure can contribute to the Program for the Conservation of Genetic Resources of this important Brazilian breed, increasing the number of embryos in germplasm banks. This study was carried out in two experiments; the first one compared the production of embryos in vivo from donors submitted to different estrous and / or superovulation synchronization protocols. The ewes received intravaginal sponges soaked in 60 mg of medroxyprogesterone acetate (MAP), which were maintained for six (G6; n = 12), nine (G9; n = 12) or 12 (G12; n = 12) days. Half of the ewes in each group remained synchronized (SYNCH) while the other half were superovulated (SOV) with porcine follicle stimulating hormone (pFSH). Of the analyzed variables, there was a difference in the beginning of estrus that occurred 10-12 h later (P <0.01) in G9SYNCH ewes when compared to G6SYNCH and G12SYNCH, and the duration of estrus was 19 h longer (P <0.01) in G9SOV than in G6SOV. The average duration of the collection procedure was 32.6 ± 1.3 min. At least one structure was recovered in 85.7 and 87.5% of the synchronized and superovulated ewes, respectively. The recovery rates of viable embryos were also similar (P> 0.05) for the synchronized and superovulated groups: G6 (1.0 ± 0.3 and 2.5 ± 1.5), G9 (1.3 ± 0, 5 and 4.8 ± 2.0) and G12 (1.0 ± 0.3 and 4.8 ± 2.3). It is concluded that pretreatment with different progesterone durations can be used in Morada Nova ewes, resulting in viable embryo recovery rates in synchronized and / or superovulated animals. In the second experiment, the number of follicles ≥ 2 mm at the time of the last dose of pFSH was correlate with the superovultory response (number of corpus luteum) and the production of embryos (number of blastocyst and embryonic quality) in synchronized ewes with the two most promising treatments from the previous experiment (G9 and G12). The total count of follicles ≥ 2 mm doubled from the 1st to the 6th pFSH dose in both groups of ewes (P < 0.05). Estrus responses did not vary between the two subsets of Morada Nova sheep and they averaged 95.2%. Corpora lutea (CL) were detected in 85.0% and 60.0% of ewes going estrus in G9 Days and G12 Days groups, respectively. NSER was successfully completed in 86.2% of all ewes studied (P > 0.05). The mean number of CL per ewe/successfully flushed donor ewe was greater (P < 0.05) in G12 (12.3 ± 1.7/12.1 ± 1.9) than in G9 (7.9 ± 1.4/8.2 ± 1.6). Mean numbers of retrieved blastocysts and viable embryos were greater (P > 0.05) for G12 (5.8 ± 1.9 and 3.7 ± 1.7) than for G9 ewes (3.5 ± 1.1 and 0.8 ± 0.3, respectively). The total follicle count when applying the 6th dose of pFSH in the G12 group was positively correlated (P <0.05) with the number of CLs (r = 0.95) and with the number of viable embryos (r = 0.91). It was concluded that estrus synchronization protocol based on the use of P4 for 12 days resulted in better superovulatory results when compared to the 9 days protocol and that the total follicle count in the last dose of pFSH was a good predictor of superovulatory response only in Morada Nova ewes treated with P4 for 12 days.
BANKING MEMBERS:
Presidente - 1548043 - MARCO ROBERTO BOURG DE MELLO
Externo ao Programa - 2142739 - RODRIGO VASCONCELOS DE OLIVEIRA
Externa à Instituição - JOANNA MARIA GONÇALVES DE SOUZA-FABJAN - UFF
Externo à Instituição - ÂNGELO JOSÉ BURLA DIAS - UENF
Externo à Instituição - JOAQUIM ESQUERDO FERREIRA - CESVA