The Vitamin D Requirements of Ducklings

The Vitamin D Requirements of Growing Ducks

“…The levels of vitamin D used ranged from 0 to 120 units per 100 grams of ration. Motzok, Graham, Branion and Slinger (1946), also using White Pekin ducklings fed on the A.O.A.C. basal diet, concluded that the requirement was in excess of 30 units per 100 grams of ration as judged by bone ash and plasma phosphatase values.…”

Studies on alkaline phosphatases. 4. Influence of dietary minerals on pH optima and reaction velocities of phosphatases of fowl

“…In experiments with added calcium and magnesium the basal diet made up 94-6% of the ration with the remainder provided by the mineral supplements and additional wheat as the other variable component. In studies with manganese * Part 3: Motzok & Branion (1961). and molybdenum (Expts.…”

“…Department of Nutrition, Ontario Agricultural College, Guelph, Canada (Received 7 August 1962) The optimum pH for alkaline phosphatase depends on such factors as the source of enzyme and the type and concentration of substrate, buffers and activators (for references see Motzok & Branion, 1961). Also, the optimum pH of fowlintestinal phosphatase changes to more alkaline values with increasing age of the birds (Motzok & Branion, 1961).…”

“…Department of Nutrition, Ontario Agricultural College, Guelph, Canada (Received 7 August 1962) The optimum pH for alkaline phosphatase depends on such factors as the source of enzyme and the type and concentration of substrate, buffers and activators (for references see Motzok & Branion, 1961). Also, the optimum pH of fowlintestinal phosphatase changes to more alkaline values with increasing age of the birds (Motzok & Branion, 1961). Although the pH optima for the various concentrations of glycerol 2-phosphate were quite constant for the intestinal enzyme of several breeds of chicks at 1 day of age, some differences have been observed among groups of older fowls of approximately the same age but given different experimental and commercial diets.…”

“…Although the pH optima for the various concentrations of glycerol 2-phosphate were quite constant for the intestinal enzyme of several breeds of chicks at 1 day of age, some differences have been observed among groups of older fowls of approximately the same age but given different experimental and commercial diets. The suggestion that the concentration of specific minerals in the diet caused some of these differences was based on the observation that the optimum pH of intestinal phosphatase was lower in hens given insoluble granite grit than in hens given oyster shell ad libitum with a diet containing about 1-2 % of calcium (Motzok & Branion, 1961).…”