An Unexpected High Requirement of Chicks for Pyridoxine

IN THE course of some recent experimental work, where simplified and purified rations were used, symptoms of pyridoxine deficiency appeared even though the rations were supplemented with pyridoxine in supposedly adequate amounts. The chicks used were day-old cockerels hatched from a cross of Rhode Island Red cocks on Barred Plymouth Rock hens. Representative rations are shown in Table 1. Pyridoxine hydrochloride was added to the diets at the rate of 500 micrograms per 100 grams of feed. The diets were stored at 4°C. during the experiment. Gains, food consumption and behavior up to 2 weeks of age were normal, but at 3 weeks the weights were about 25 percent below normal. Food consumption was poor and some leg weakness was noted. At the end of the third week one chick was observed with its head turned under as is shown in Figure 1 (chick A), and several others showed symptoms . . .