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

• Published in: Theriogenology 2020-10, Vol.155, p.132-138
• Main Authors: Figueira, Lucas Machado, Alves, Nadja Gomes, Maia, Ana Lucia Rosa e Silva, Souza-Fabjan, Joanna Maria Gonçalves de, Batista, Ribrio Ivan Tavares Pereira, Morais, Maria Clara da Cruz, Lima, Renato Ribeiro de, Oliveira, Maria Emilia Franco, Fonseca, Jeferson Ferreira da
• Format: Article
• Language: English
• Subjects: Animals; Corpus Luteum; Dairy sheep; Female; Follicle Stimulating Hormone; Lactation; MOET; Progestins; Sheep; Superovulation; Transcervical; Uterine flushing
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2020.06.004

This study assessed the effect of progestogen treatment length on ovarian parameters and embryo yield in superovulated Lacaune ewes collected by nonsurgical embryo recovery. Twenty-three lactating ewes were superovulated 30 d apart using a cross-over design. All ewes received 60 mg of MAP intravaginal sponges for 6 (G-6 group) or 9 (G-9 group) d. A total dose of 133 mg pFSH was given in six decreasing doses (twice a day) starting at 60 h before device removal. Ultrasound examination of the ovaries was performed at the first pFSH injection and one day before embryo recovery, which was performed 6–7 d after the onset of estrus. Embryo recovery was conducted only in ewes that expressed estrus and were mated. There was no difference (P > 0.05) in the total number of follicles between G-6 (15.7 ± 1.0) and G-9 (15.6 ± 0.8) at the time of the first pFSH treatment. The percentage of responding donors with ≥3 corpora lutea (CL; 78.2% [18/23] vs 69.5% [16/23]), mean (±SEM) CL number (7.0 ± 1.2 vs 8.1 ± 1.6), transcervical passage rate (94.4% [17/18] vs 83.3% [15/18], and ova/embryo recovery rate (54.5% [60/110] vs 68.0% [83/122]) were not different (P > 0.05) between the G-6 and G-9 groups. However, the mean number of viable embryos was lower (P