Variations in the quality of butter, particularly in relation to the vitamin A, carotene and xanthophyll content as influenced by feeding artificially dried grass to stall-fed cattle

Abstract

The values for carotene, xanthophyll. and vit. A contents of butters from cows fed on normal winter rations of hay and concentrates fell steadily during the winter and remained low until fresh grass was fed. An increase in the content of the 2 carotenoids and vit. A appeared soon after the change over from the control diet in the butters from cows fed on artificially dried N-treatcd grass, and an even greater increase in the butter from cows fed artificially dried N-fertilized grass. Grass silage was little better than normal winter ration in its effect on color and vit. A of the butter. The presence of ergosterol in the unsaponifiable matter of grass was established.