Description and genetic analysis of three sets of monozygotic twins resulting from transfers of single embryos to recipient mares.

Case Description: 3 sets of monozygotic twins resulting from transfers of single embryos to recipient mares were examined.

Clinical Findings: In all 3 recipient mares with twin pregnancies, only 1 embryonic vesicle was detected before day 25 of gestation. In 1 recipient mare, 2 apparent adjacent vesicles, each containing an embryo with a heartbeat, were visualized on ultrasonographic examination on day 37 of gestation.

Factors impacting equine sperm recovery rate and quality following cushioned centrifugation.

Two experiments were conducted to investigate modifications in cushioned centrifugation of stallion semen. Specifically, the effects of tube type, centrifugation medium, cushion type, and centrifugation force on post-centrifugation sperm recovery rate and quality were evaluated. In Experiment 1, sperm recovery rate was higher (P<0.