Effect of Diphenyl-p-Phenylenediamine on the Utilization of Carotene and Vitamin A by the Calf

High dietary levels of DPFD (3 to 10 g/100 lb. body weight) were administered to dairy calves in an attempt to assess the toxicity of this antioxidant. There was an indication of a depression of growth when DPPD was first introduced into the diet; thereafter, the DPPD apparently had little effect upon the health of the calves. Criteria used were weight gains, blood cell counts, hemoglobin levels, and general health observations The absorption curve technique was employed to study the effect of DPPD upon the absorption of vitamin A and carotene. At the high dietary levels used in the study of toxicity, DPPD impaired the absorption of vitamin A. When DPPD was fed at lower concentrations (250 p.p.m, in the diet), there was an indication that DPPD improved the absorption of vitamin A slightly. At the lower dietary concentration, DPPD improved the absorption of carotene. In the course of a long-term depletion experiment, it became evident that DPPD or some derivative thereof was absorbed from a diet containing a high level of DPPD (3 g/100 lb. body weight). The absorbed DPPD or DPPD product probably interfered with the analytical technique and thus caused an ap-paren t in crease in the plasma levels of vitamin A and carotenoids. When DPPD feeding was discontinued,a sudden drop in the plasma level of apparent DPPD occurred, in dicatingrapid metabolism of this compound.