title: A decapitated sperm defect in two sterile Hereford bulls.
abstract: Two almost identical cases of sterility in young Hereford bulls have been investigated. Semen samples sent to the laboratory showed normal sperm concentradition and abnormal sperm morphology. In 80-95% of the sperm cells, head and tail were separated, and similar to what has been found in the 'decapitated sperm defect' in the Guernsey breed, a high percentage of the loose tails were able to perform active movements. A third characteristic was a proximal bending or curling of the loose tail around the cytoplasmic droplet, a detail which by lower magnification might be mistaken for a mini-head. The possible heredity of the defect is discussed.
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology; D002452:Cell Count; D007248:Infertility, Male / Q000473:pathology / Q000662:veterinary*; D008297:Male; D013077:Sperm Head / Q000473:pathology; D013082:Sperm Tail / Q000473:pathology; D013094:Spermatozoa / Q000473:pathology*