Skin Grafts: Delayed Rejection between Pairs of Cattle Twins Showing Erythrocyte Chimerism

Abstract
Although dizygotic cattle twins with erythrocyte chimerism exhibit complete tolerance to each other's hematopoietic tissues exchanged in utero by way of chorionic anastomoses, they may not be completely tolerant to each other's histocompatibility antigens. Skin grafts exchanged between partners of 21 pairs of chimeric twins were rejected by more than half of the twins in an average of 250 days.