The effect of flunixin meglumine on the premature regression of corpus luteum, recovery rate, and embryo production in superovulated Dorper ewes.

This study evaluated the use of flunixin meglumine to prevent the occurrence of premature corpus luteum (CL) regression in superovulated ewes, improving embryo recovery and viability. Ewes (n=23) submitted to conventional superovulatory protocol and laparoscopic artificial insemination were treated with 2.2 mg/kg/day of flunixin meglumine (FLU, n=12) or 1.5 mL saline solution (CONT, n=11) on Days 2, 3, and 4 (Day 0 = 48 h after device removal). Serum progesterone (P4) concentrations were measured (Day 1-6). Ultrasound (US, Days 3 and 6) and laparoscopic evaluation (Day 6) were performed to identify luteinized structures. In the US, laparoscopy, and P4 assessments, the percentage of ewes with premature CL regression differed (P<0.05) between CONT (54.5; 63.6; and 54.5 %) and FLU (0.0; 0.0; and 0.0 %), respectively. The US exams revealed the effect (P<0.05) of treatment on the number of regressing CL between CONT (1.4 ± 0.6) and FLU (0.0 ± 0.0). Greater (P<0.05) number of normal CLs (10.5 ± 1.8 vs. 4.4 ± 1.5), ova/embryos (9.1 ± 2.1 vs. 3.7 ± 1.3), viable embryos (5.1 ± 1.1 vs. 2.6 ± 1.2), and recovery rate (79.5 ± 9.6 vs. 41.3 ± 15.0 %) were observed in FLU compared to CONT, respectively. The embryo viability rate did not differ (P>0.05) between FLU (60.7 ± 10.5 %) and CONT (45.5 ± 16.1 %). In conclusion, the flunixin meglumine protocol was able to prevent the occurrence of premature CL regression in superovulated ewes, increasing the recovery rate and embryo production.

In vivo embryo production and recovery in lacaune ewes after imposing a superovulation treatment regimen is related to pFSH dose.

This study was conducted to assess effects of different doses of pFSH on follicular recruitment, superovulatory response, ova/embryo recovery, and embryo yield in lactating ewes. Ewes (n = 24) had a superovulation treatment regimen imposed. All ewes were implanted with a progesterone intravaginal device for 9 d, and administered either 100 (G-100) or 200 (G-200) mg pFSH, proportioned into six doses administered at 12-h intervals, starting 60 h before device removal. At 7 days subsequent to progesterone device removal, there were non-surgical embryo recoveries (NSER) from ewes having three or more corpora lutea. At the time of the first pFSH injection, number of antral follicles were similar (P < 0.05) between ewes in the G-100 and G-200 group, however, there were more 3.1-4.0 mm follicles in ewes of the G-200 than G-100 group at the time of the second pFSH administration. Estrous response and CL number were less (P < 0.05) in ewes of the G-100 (66.7 % and 2.6 ±â€¯0.7) than G-200 (91.7 % and 11.6 ±â€¯1.2) group. There were embryo collections from 100 % and 90.9 % of ewes in the G-100 and G-200 groups, respectively (P > 0.05). Viable embryo numbers and ova/embryo recovery rate were greater (P < 0.05) in ewes of the G-200 (6.9 ±â€¯1.1 and 67.8 %) than G-100 (1.0 ±â€¯0.5 and 27.6 %) group. A dose of 200 mg pFSH was more effective in inducing a superovulatory response and embryo yield after NSER in ewes, however, the 100 mg dose was insufficient for these purposes.

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

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 < 0.05) in the G-6 group (1.8 ± 0.7) than in the G-9 group. (3.5 ± 1.1). In conclusion, treatment with an intravaginal MAP sponge for 9 d during a superovulation protocol is beneficial for viable embryo yield in Lacaune ewes out of the breeding season.