Embryo yield and quality are associated with progestogen treatment during superovulation protocol in lactating Lacaune ewes

A study of the factors affecting embryo yields and quality in superovulated Morada Nova ewes that underwent non‐surgical uterine flushing

“…In the ewes of the present study, only 60% (G‐9 SOV ) and 67% (G‐12 SOV ) of all recovered structures were viable embryos. These proportions are similar to those reported in previous studies using the same mating strategy in Morada Nova (G‐9 SOV , 60.0% and G‐12 SOV , 70.5%, respectively; Arrais et al., 2021) and Lacaune ewes (G‐9 SOV , 62.7%; Figueira, Alves, Maia, Souza‐Fabjan, Batista, Morais, et al., 2020) superovulated in the same superovulatory pFSH regimen (133 mg of pFSH in decreasing daily doses). In another study, Morada Nova ewes had 46.9% (68/49) of viable embryos after 14 days of P 4 priming and 133 mg of pFSH, followed by laparoscopic insemination performed 50 hr after device removal (Brasil et al., 2016).…”

“…ovarian responses and resultant embryo yields) attributed to multiple extrinsic and intrinsic influencing factors (Bartlewski et al, 2016). The duration of oestrus synchronization protocols with progestin-releasing intrauterine devices has dissimilar effects on the success of superovulatory treatments in different breeds of sheep (Figueira, Alves, Maia, Souza-Fabjan, Batista, Morais, et al, 2020;Menchaca et al, 2009;Oliveira et al, 2014Oliveira et al, , 2020. While the period of progesterone or progestin exposure in Merino (5-14 days, Menchaca et al, 2010) and Santa Inês ewes (6.5 vs 14.5 days, Oliveira et al, 2020) had a limited effect on in vivo embryo production, the 9-day treatment with medroxyprogesterone acetate was associated with better outcomes compared with the short-term (6 days) protocol in Lacaune ewes (Figueira, Alves, Maia, Souza-Fabjan, Batista, Morais, et al, 2020).…”

“…The duration of oestrus synchronization protocols with progestin-releasing intrauterine devices has dissimilar effects on the success of superovulatory treatments in different breeds of sheep (Figueira, Alves, Maia, Souza-Fabjan, Batista, Morais, et al, 2020;Menchaca et al, 2009;Oliveira et al, 2014Oliveira et al, , 2020. While the period of progesterone or progestin exposure in Merino (5-14 days, Menchaca et al, 2010) and Santa Inês ewes (6.5 vs 14.5 days, Oliveira et al, 2020) had a limited effect on in vivo embryo production, the 9-day treatment with medroxyprogesterone acetate was associated with better outcomes compared with the short-term (6 days) protocol in Lacaune ewes (Figueira, Alves, Maia, Souza-Fabjan, Batista, Morais, et al, 2020). Results of a preliminary study comparing embryo yields in superovulated and oestrussynchronized, non-superovulated Morada Nova ewes subjected to progesterone-based oestrus synchronization protocols of varying durations (6, 9 or 12 days) showed that the 9-and 12-day protocols resulted in better embryo recovery rates than the 6-day regimen (Arrais et al, 2021), but a confirmatory trial is still needed.…”

“…However, the predictive value of antral follicle counts at the first exogenous FSH dose remains equivocal (Bartlewski et al, 2016). While some studies reported positive correlations between the numbers of small antral follicles (2-3 mm; Brebion & Cognié, 1989) or all detectable antral follicles (≥2 mm in diameter; Figueira, Alves, Maia, Souza-Fabjan, Batista, Morais, et al, 2020) present at the beginning of the superovulatory treatment and the resultant embryo yields in ewes, other studies refuted the existence of such correlations (Arrais et al, 2021;Bartlewski, Alexander, & King, 2008). The number of CL in superovulated ewes is approximately twice the number of small antral follicles recorded at the time of the first FSH dose (Arrais et al, 2021;Bartlewski et al, 2015), suggesting that ovulatory follicles are recruited throughout the 3-or 4-day superovulatory treatment.…”

>b<Estratégias para otimizar a técnica de múltipla ovulação e transferência de embriões em ovinos>/b<

“…O maior benefício da biotecnologia está relacionado à velocidade do melhoramento genético a partir da diminuição no intervalo das gerações, porém a MOTE apresenta alguns entraves como o alto custo e a variabilidade na resposta superovulatória (FORCADA et al, 2011;AMIRIDES;CSEH, 2012;FIGUEIRA et al, 2020). De acordo com Oliveira et al (2013), fatores como a seleção das doadoras, protocolo hormonal, método de fertilização e a técnica de coleta dos embriões poderão interferir no resultado da biotecnologia.…”