An effect of formulation on the incidence of DDT residues in milk

Abstract

Two groups of three cows were dipped in two different formulations of 0.5 per cent DDT over ten fortnightly dipping rounds to investigate the effect of formulation on the level of DDT residues in milk. Milk samples were taken just before and three days after each dipping and assessed for DDT content. DDT was found to be excreted at a higher rate in the butterfat after dipping in a supercooled melt formulation than after dipping in a wettable powder. This may be due to increased deposition of DDT on animal hair (as reported by others) and/or to the effect of a solubilizing agent present.