2,4-D (2,4-Dichlorophenoxyacetic acid) and related compounds 
In feeding studies of 2,4-D with dairy cows and steers (Lisk et al., 
1963; Gutenmann et al., 1963a,b; Bache et al., 1964a,b), 2,4-D was found 
unchanged in the urine only. No evidence of beta-oxidation was found. 
Similar findings were obtained with sheep. Ninety-six percent of an 
orally administered dose of 2,4-p-cl4 to a sheep was excreted unchanged 
in the urine in 72 hours and slightly less than 1.4% in the feces. Very 
little residual radioactivity was found in edible tissue (Clark et al., 
1964). Cows fed 2,4,5-T and silvex excreted both as soluble salts in their 
urine. Kuron was hydrolyzed to silvex prior to elimination (St. John 
et al., 1964). 
Treatment of lemons with cl4 labeled 2,4-D isopropylester indicated 
that the ester was hydrolyzed and that part of the 2,4-D then reacted with 
some plant constituent to form an ester-like complex. Ester-like residues 
were also found after treatment with the sodium, Ha givatoteceines or 
triethanolamine salts (Erickson and Nield, 1962; Erickson et al., 1963). 
Hydrolysis (Crafts, 1960; Morre and Rogers, 1960) and decarboxylation 
(Edgerton and Hoffman, 1961; Basler, 1964) of 2,4-D by other plants has 
also been shown. 
Plants are capable of hydroxylating phenoxyacetic acids (Wilcox et al., 
1963; Thomas and Loughman, 1963). When bean plants were treated with 
2,4-D, three compounds were found (Crosby, 1964). One corresponded roughly 
to that of 2,4-dichloroanisole; one was a water-soluble, ether-insoluble 
ester derivative; and the third, an ether-soluble compound with a basic 
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