The occurrence of an antigen associated with pregnancy in the ewe.
D000818:Animals; D000941:Antigens / Q000032:analysis*; D000939:Epitopes; D005260:Female; D005779:Immunodiffusion; D010053:Ovary / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal; D012756:Sheep; D014327:Trophoblasts / Q000276:immunology; D014599:Uterus / Q000276:immunology*
D000941:Antigens; D000939:Epitopes