The Effect of Mineral Supplements on the Availability of Manganese

Abstract

IT HAS been recognized for some time that poultry develops perosis if the ration is deficient in Mn or contains an excess of mineral supplements, such as bone meal or oyster shell (Wilgus, Norris, and Heuser, 1937; Schaible, Bandemer, and Davidson, 1938). It has also been shown (Bandemer and Schaible, 1942) that the concentration of insoluble Ca and P is considerably greater in the intestinal contents when chicks are fed high-mineral rations. The present study was made to determine if such insoluble material reduces the solubility of Mn and, in this manner, decreases its availability to the chick. If so, the similar effects of high-mineral and Mn-deficient rations would be explained. EXPERIMENTAL Effect of Mineral Supplements upon Mn in Solution To simplify matters, experiments were first carried out in vitro under conditions roughly approximating those in the gastrointestinal tract. Varying amounts of bone meal, c.p. Ca3(PO4)2, or oyster shell were . . .