Effect of Trace Minerals and Other Dietary Ingredients Upon Carotene Stability in Stored Poultry Diets

IT HAS become a common practice to add certain trace minerals and vitamin A to mixed feeds of poultry and livestock. Whether or not this procedure has practical merit depends in part upon the stability of carotene or vitamin A in the presence of free trace minerals and other dietary ingredients. Miller et al. (1942), Halpern et al. (1949), Halverson and Hart (1950) and other investigators have demonstrated the destructive effect of free trace minerals upon vitamin A of cod liver oil in mixed feeds. Studies by Holder and Ford (1939) and Bethke et al. (1939) also indicated a destructive effect of meat scraps upon vitamin A of cod liver oil in mixed feeds. Studies by Fraps and Kemmerer (1937) found alfalfa meal a slightly more stable source of vitamin A in stored feeds than cod liver oil. Bethke et al. (1939) in a similar study could not differentiate between . . .