Effect of eCG in a short-term synchronization treatment on ovarian status, estrus synchrony, and ovulation in dairy goats managed under tropical conditions.

The aim of this study was to assess the need of using eCG on short-term estrus synchronization protocol in nulliparous (NUL) and multiparous (MULT) dairy goats during the breeding season. Alpine (n = 20), Nubian (n = 20), and Saanen (n = 16) goats received 60 mg medroxyprogesterone acetate intravaginal sponges for 6 days plus 30 µg d-cloprostenol and 200 IU eCG (G-eCG, n = 28) or saline (G-Control, n = 28) 24 h before sponge removal. The NUL and MULT goats of each breed were equally assigned into the two treatments. Transrectal ultrasonography was used to evaluate ovulatory parameters, and teaser goats were used for estrus detection every 12 h from sponge removal to ovulation. eCG did not affect (P > 0.05) estrus response (~86%), diameter of ovulatory follicles (~6.8 mm), and number of ovulations (~1.6). Nevertheless, eCG led to earlier (P < 0.05) ovulation (G-eCG = 65.1 and G-Control = 73.2 h) and increased (P < 0.05) the ovulation rate (G-eCG = 96.4% and G-Control = 67.9%). In the absence of eCG, no differences regarding reproductive parameters (P > 0.05) were found between parity orders. Alpine MULT goats underwent a superior (P < 0.05) number of ovulations (2.2) in comparison to NUL goats (1.3). In conclusion, the exclusion of eCG from short-term estrus synchronization protocol did not interfere with estrus response but decreased the ovulation rate.

Spectral Doppler ultrasound in selecting an equine embryo receiver.

The aim of this study was to evaluate whether the RI and PI values would help in choosing the best embryo recipient, and observe whether CL vascularization would influence P4 production. During the breeding season 2018/2019, the study was conducted using 35 mares, which is used for reference to collect data for the project on the day of embryo transfer. The utilized mares were divided into five groups followed by the day after ovulation, with D0 being the day of ovulation. Therefore, the five groups are as follows: D4-mares that were on the 4th post-ovulation day; D5-mares that were on the 5th post-ovulation day; and doing so successively for D6, D7 and D8. On the day of embryo transfer, the CL of the mares that selected as recipients was evaluated by B-mode and power flow mode ultrasonography and the right and left dorsal branches of the uterine arteries by spectral Doppler ultrasonography. Blood samples were taken on the day of the embryo transfer for a dosage of P4 concentration by radioimmunoassay. No statistical difference was found between the variables when the mares were separated into pregnant and non-pregnant mares, or when they were separated by age groups. When the groups of mares were compared by the day of embryo transfer, the statistical difference was found between the groups D5 × D6 (p = .0053) and D6 × D8 (p = .0036) in RI variable. In PI variable, the statistical difference was found between the groups D4 × D8 (p = .049), D5 × D6 (p = .0446) and D6 × D8 (p = .0024). We conclude that the mares with RI measurement of uterine arteries near 1.0 are correlated to mares with high CL vascularization and elevated P4 concentration.