Progesterone supplementation during multiple ovulation treatment in buffalo species (Bubalus bubalis).

The aim of this study was to evaluate the effect of exogenous progesterone supplementation on superovulatory response in buffaloes that has undergone a multiple ovulation program. Fourteen Mediterranean buffaloes were divided into two groups and received a 4-day decreasing dosage of an equal mixture of 500 IU of FSH and LH starting on day 8 of the cycle. In group A (n=7) a progesterone-releasing intravaginal device was removed on day 8, whereas in group B (n=7) it was left till day 10, when PGF2a was administered. Eighty hours later, buffaloes were artificially inseminated and after 6 days they undergone uterine flushing. A higher (P<0.05) number of corpora lutea (8.3 vs. 5.7) and embryo/flushing/buffalo (2.3 vs. 1.3) were recorded in group B vs. group A if responsive buffaloes are considered (n=12) and the number of corpora lutea was highly correlated with the number of embryos (r=0.65; P<0.05). In conclusion, progesterone supplementation during the first 2 days of the superovulation treatment seems to enhance the recovery rate in buffalo species. A high ovulation rate, associated with a high number of corpora lutea, can represent a parameter for estimating embryo recovery.