The Influence of Breed, Feed, and Processing on the Riboflavin Content of Milk

Abstract

Experiments with two Holstein-Friesian and two Jersey cows over a normal lactation period of approximately 10 months (samples taken twice weekly) showed: 1 The milk of two Holstein cows used in this experiment contained, on’an average, approximately 34 per cent less riboflavin than that of two Jersey cows. 2 The Holstein cows, because of higher milk production, produced on an average approximately 34 per cent more riboflavin per day than the Jersey cows. 3 There was an inverse relation between milk yield per day and the riboflavin content. 4 The riboflavin content of morning, noon, and night milk from the same cow was practically constant although the milk yields varied widely. 5 Supplementing a concentrate-dry roughage ration with substantial amounts of sunflower silage increased the riboflavin content of milk 36 per cent (within 2 days), and the riboflavin content level was comparatively high for the remaining portion of lactation while the silage was fed. 6 Supplementing a concentrate-dry roughage sunflower-silage ration with wheat pasture or sweet clover and wheat pasture caused no significant change in the riboflavin content of milk. 7 Stage of lactation, season, pregnancy, and oestrus have no discernible influence on the riboflavin content of milk. 8 Colostrum milk contains about three times as much riboflavin as normal milk but loses approximately 30 per cent of its riboflavin concentration within 24 hours after parturition of the cow. 9 Neither pasteurization, homogenization, or storage for 24 hours at 40° F. in a dark refrigerator decreased the riboflavin content of milk. © 1945, American Dairy Science Association. All rights reserved.