Artificial insemination in Italian Mediterranean Buffalo cows.

Artificial insemination (AI) represents a valid method to obtain genetic improvement through male lineage. The aim of this study was to compare two synchronization protocols in buffaloes. Animals were divided in two groups: Group A (n=111) was treated with the Ovsynch/TAI Program (100 μg GnRH -Enagon®, Gellini- at day 0, 375 μg PGF2α -Cystrinol®, Gellini- at day 7 and 100 μg GnRH at day 9); Group B (n=117) received a intravaginal drug release device (PRID®, Gellini), containing 1.55 g of progesterone and 10 mg of oestradiol benzoate at day 0 for 10 days and, after PRID withdrawal, two injections respectively of 375 μg PGF2α and 1000 I.U. PMSG (Folligon®, Intervet). Animals were inseminated twice: 18 and 42 hours after the second injection of GnRH (Group A) and 60 and 84 hours after PGF2α and PMSG injections (Group B). Pregnancy was assessed 40 days after the last insemination and confirmed at 90 days by rectal palpation. Group B presented a higher number of animals with an appropriate luteinic phase (>150 pg/ml milk serum) 10 days after AI vs. Group A (93.2% vs. 81.1%; P<0.01). Pregnancy rate was not significantly different among the two protocols, although Ovsynch/TAI Program showed better outcomes than PRID (respectively 36.0% vs. 28.4%). If data are referred to animals with an appropriate luteinic phase after treatment, Group A presented a higher pregnancy rate than Group B (44.4% vs. 30.3%; P<0.05). These results suggest that Ovsynch program may support a higher pregnancy rate than PRID if animals are cyclic.