title: Middle piece defects of testicular origin in bull sperm.
mesh_terms: D000818:Animals; D002417:Cattle / Q000033:anatomy & histology*; D004822:Epididymis / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D013094:Spermatozoa / Q000002:abnormalities* / Q000648:ultrastructure; D013737:Testis / Q000648:ultrastructure