The purpose of this study was to reduce of early twin pregnancies to single pregnancies in the mares by crushing.
Out of 671 pregnancies that were diagnosed by rectal ultrasonography 2-4 weeks after ovulation. 21 (3.11 %) twins were diagnosed. Vesicles were present in left horn in 16 (76.1 %) mares and in right horn in 5 (23.8%) mares.
Although, twin pregnancies were successfully reduced to single pregnancies in 15 mares, both vesicles resorbed in 2 (9.5%) marcs and vesicles developed normally even if crushed in 4 (19.0%) mares. Crushed twins rechecked on 5 days after crushing and persistent twin pregnancy terminated by prostaglandin F2 alfa in 4 mares. They re-mated in the first oestrus after prostaglandin injections to achieve normal pregnancy in the same breeding season.
The success rate Tor crushing, day 16-22 embryos was %78.9 and %42.8 for crushing day 22-28 embryos.