Studies in vitamin A. 15. The variations in the serum beta-carotene and vitamin A levels of cows near parturition.
D000818:Animals; D002417:Cattle; D005260:Female; D014801:Vitamin A / Q000097:blood*; D019207:beta Carotene
D019207:beta Carotene; D014801:Vitamin A
CATTLE; VITAMIN A/in blood