Studies on the Pyridoxin Requirements of Laying and Breeding Hens

IN A previous paper, Cravens, Sebesta. Halpin and Hart (1943) demonstrated the essential nature for pyridoxin for egg production, hatchability and the maintenance of body weight in mature fowl. Although 1.0 mg. of added pyridoxin per kilogram of ration appeared to give results comparable to the higher levels fed, no attempt was made from this experiment to define the requirements of laying hens for this vitamin. We wish to report here the results of a further experiment designed to determine the pyridoxin requirements of laying and breeding hens. EXPERIMENTAL Single Comb White Leghorn pullets from the Experiment Station flock were used in this experiment. These birds were reared on range and placed in an individual cage laying battery September 1, 1942. From this time until December 14, 1942, when the experimental feeding was started, the birds were fed a practical breeding mash with grain. Just prior to the experimental period, . . .