Effect of Feeding Various Levels of N,N′-Diphenyl-para-Phenylenediamine to Lactating Dairy Cows and its Detection in the Milk

Abstract

Summary Twenty cows, five Guernseys and 15 Holsteins, were selected for producing milk which exhibited oxidized flavor 72 hours after the addition of 5 p.p.m. Cu ++ . After a 1-week standardizing period, the cows were fed one of five levels of DPPD, 0.0000, 0.0001, 0.0010, 0.0100, or 0.1000% of the total ration fed (90% dry matter basis) for a 5-week comparison period. All levels of DPPD resulted in significant increases in per cent fat of the milk. Similarly, milk vitamin A was significantly increased. All levels of DPPD reduced the incidence of oxidized flavor in the presence of 1 p.p.m. of Cu ++ and the two highest levels in the presence of 5 p.p.m. of Cu ++ . DPPD was qualitatively found in milk of the cows fed the three highest levels of DPPD and quantitatively in the highest level. In the last case, the concentrations of DPPD averaged 32.5 γ/100ml. of milk, which represented a mammary transfer of 0.032% of the DPPD fed.