Residues of dalapon in chicken tissues and eggs following repeated feeding

Abstract

Groups of 12 hens were fed continuously on feed containing 0, 25, and 50 p.p.m. of dalapon. Eggs were collected during this period. At the end of 30 days, five hens from all groups were sacrificed. Tissues collected were lean meat, skin and fat, liver, gizzard, kidney, blood, and feathers. At the end of 60 days, the remaining hens were sacrificed. Residues of dalapon were determined by electron-capture gas chromatography. Residue values, determined for all the tissues from each individual hen, were roughly proportional to the level of feeding. Maximum values for eggs at the 50 p.p.m. level of feeding were 2 p.p.m.; for meat, skin and fat, liver, gizzard, and feathers, the maximum was about 15 p.p.m., while blood rose to 40 and kidney to 50 p.p.m. Dowpon grass killer, containing the sodium salt of dalapon, 2,2-dichloropropionic acid (Dalapon is a trade-mark of The Dow Chemical Co. outside the U.S.), has been used extensively for several years to control problem grasses in a number of crops. Extensive residue studies have been carried out over several years to determine dalapon acid residues. The first report of these was the finding of no residue in sugar cane treated with Dowpon by Smith et al. (1957). Schreiber (1959) reported on the residues of dalapon in Birdsfoot trefoil from a number of different applications of the herbicide and showed that there is wide variation of residue content depending on the rate and timing of the application of Dowpon.Mac Collom and Flanagan (1967) studied residue disappearance from trefoil related to time. Kutschinski (1961) and Fertig and Schreiber (1961) have reported on dalapon residues in milk, and Getzendaner et al. (1965) studied the residue situation on citrus fruit from a wide variety of application schedules. Archer et al. (1967) have studied dalapon residues in asparagus.Tolerances have been established on a wide variety of crops by the Food and Drug Administration (Federal Register, 1963). With tolerances for residues being established in corn, grain, and the possibility of further tolerances in forage crops, chickens may be exposed occasionally to diets containing traces of dalapon. This experiment was carried out to determine the residue levels of dalapon in chicken tissues and eggs which would result from repeated ingestion of feed containing fixed concentrations of this chemical. This experiment was designed to show the variation of residue in the tissues between birds from normal consumption patterns. The feed eaten Agricultural Products Department, The Dow Chemical Co., Midland, Mich. by each group was all at the same concentration, so the consumption pattern of each chicken was the controlling factor on the intake of chemical, which was reflected in the residue levels in individual tissues. EXPERIMENTAL Three groups of 12 mature White Rock laying hens were randomly selected. Feed was prepared starting with Farm Bureau Mermash, 20% protein, manufactured by a local elevator. The calculated amount of dalapon was added to 200-pound batches to make 0, 25, and ...