Variations in the carotene and vitamin A contents of Queensland butterfat

Abstract

Butter samples were submitted at fortnightly intervals in 1954 and 1955 from 12 dairying centres, predominantly in south-eastern Queensland. Each sample was representative of cream supplies received at the particular butter factory at the time of sampling. The marked seasonal variations in the total vitamin A potency of butterfat may be related to the stage of lactation and to other factors which affect production in the dairy cow. Variations do not appear to be a function of the level of carotene in the pasture ingested by the grazing animal.