title: Blindness and sexual dimorphism associated with vitamin A deficiency in feedlot cattle.
abstract: Clinical, ophthalmoscopic, and histopathologic findings of vitamin A deficiency in a group of 535 feedlot cattle are described. Liver vitamin A content and results of histologic examination of ocular and osseous (optic canal) tissue confirmed the diagnosis. Blindness was the only clinical sign observed. Even though the steers and heifers in this feedlot were approximately the same age and were fed the same ration for an equal period, none of the heifers had overt clinical signs of hypovitaminosis A. Production of vitamin A by the bovine corpus luteum may account for the sexual dimorphism observed in vitamin A-deficient cattle.
authors.affiliation: Department of Clinical Sciences, Veterinary Teaching Hospital, Colorado State University, Fort Collins 80523.
authors.forename: M E
authors.initials: ME
authors.lastname: Paulsen
authors.forename: L
authors.initials: L
authors.lastname: Johnson
authors.forename: S
authors.initials: S
authors.lastname: Young
authors.forename: R W
authors.initials: RW
authors.lastname: Norrdin
authors.forename: G A
authors.initials: GA
authors.lastname: Severin
authors.forename: A P
authors.initials: AP
authors.lastname: Knight
authors.forename: V
authors.initials: V
authors.lastname: King
mesh_terms: D000818:Animals; D001766:Blindness / Q000209:etiology / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases; D005260:Female; D008297:Male; D012727:Sex Characteristics; D014802:Vitamin A Deficiency / Q000150:complications / Q000662:veterinary*