Metabolism of 2,4-dichlorophenoxyacetic Acid in Laying Hens and Lactating Goats

J Agric Food Chem. 2001 Jan;49(1):156-63. doi: 10.1021/jf000119r.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,4-Dichlorophenoxyacetic Acid / pharmacokinetics*
  • Adipose Tissue / chemistry
  • Animals
  • Carbon Radioisotopes
  • Chickens / metabolism*
  • Chromatography, High Pressure Liquid
  • Feces / chemistry
  • Female
  • Goats / metabolism*
  • Kidney / chemistry
  • Lactation*
  • Liver / chemistry
  • Mass Spectrometry
  • Milk / chemistry
  • Muscles / chemistry
  • Pesticide Residues / analysis


  • Carbon Radioisotopes
  • Pesticide Residues
  • 2,4-Dichlorophenoxyacetic Acid