title: Metabolism of 2,4-dichlorophenoxyacetic acid in laying hens and lactating goats.
abstract: 2,4-Dichlorophenoxyacetic acid (2,4-D) labeled with (14)C was found to be rapidly eliminated by laying hens and lactating goats dosed orally for 7 consecutive days at 18 mg/kg of food intake and for 3 consecutive days at 483 mg/kg of food intake, respectively. Excreta of hens and goats contained >90% of the total dose within 24 h after the final dose. Tissue residues were low and accounted for <0.1% of the dose in these animals. For hens, the residues in muscle, liver, and eggs (0.006-0.030 ppm) were lower than those found in fat and kidney (0.028-0.714 ppm), 2,4-D equivalents. The tissue with highest residue in goat was the kidney at 1.44 ppm, 2,4-D equivalents. Milk, liver, composite fat, and composite muscle had significantly lower residue levels of 0.202, 0.224, 0.088, and 0.037 ppm, respectively. The most abundant tissue residue was 2,4-D and acid/base releasable residues of 2,4-D. A minor metabolite was identified as 2,4-dichlorophenol.
authors.affiliation: ABC Laboratories, Inc., 7200 East ABC Lane, Columbia, Missouri 65205, USA. debarnekow@dowagro.com
authors.forename: D E
authors.initials: DE
authors.lastname: Barnekow
authors.forename: A W
authors.initials: AW
authors.lastname: Hamburg
authors.forename: V
authors.initials: V
authors.lastname: Puvanesarajah
authors.forename: M
authors.initials: M
authors.lastname: Guo
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000493:pharmacokinetics*; D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D002250:Carbon Radioisotopes; D002645:Chickens / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005243:Feces / Q000737:chemistry; D005260:Female; D006041:Goats / Q000378:metabolism*; D007668:Kidney / Q000737:chemistry; D007774:Lactation; D008099:Liver / Q000737:chemistry; D013058:Mass Spectrometry; D008892:Milk / Q000737:chemistry; D009132:Muscles / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis
chemical_list: D002250:Carbon Radioisotopes; D010573:Pesticide Residues; D015084:2,4-Dichlorophenoxyacetic Acid