Blood progesterone concentration and ovarian response of Mediterranean buffalo cows superovulated with PMSG or HMG

อังกฤษ

BUFFALO;BUBALUS BUBALIS;PROGESTERONE;PMSG;SUPEROVULATION;FOLLICLE-STIMULATING;MEDITERRANEAN BREED;HORMONE

Twelve buffalo cows were superovulated with a single dose of 2500 UI of PMSG (n=7) or 1050 UI of HMG (n=5) in decreasing doses during five days. The embryos were collected 6-7 days after mating or insemination. The animals were slaughtered after the embryos were collected and the ovarian structures were counted. Blood samples were collected at the beginning of all treatments, mating, and slaughter. Plasma samples were examined for progesterone (P4) by radioimmunoassay. At the beginning of the treatments seven females (58.3 percent) had P4 GT 1 ng/ml with four of them showing more than three ovulations. Animals with P4 concentrations LT 1 ng/ml had less than two ovulations. Thee was a positive correlation (r=0.75) between the ovulation number and the P4 concentration at slaughter. The number of follicles stimulated with PMSG (X=6.6) was significantly greater (P LT 0.05) than HMG (X=3.2). An average of 2.3 and 3.0 corpus luteum were found for PMSG and HMG treatments respectively (P GT 0.05). Our results indicate that the great variation of progesterone levels at the time of superovulation contribute to weak ovarian response in buffalo.

[1] Alvarez, P.H. (Instituto de Zootecnia. Cx. Postal 60. 13460. Nova Odessa SP, (Brazil))
[2] Nogueira, J.R. (Instituto de Zootecnia. Cx. Postal 60. 13460. Nova Odessa SP, (Brazil))
[3] Meirelles, C.F. (Centro de Energia Nucler na Agricultura. Cx. Postal 9. 13400. Piracicaba SP. (Brazil))
[4] Baruselli, P.S. (Instituto de Zootecnia. Cx. Postal 60. 13460. Nova Odessa SP, (Brazil))