TABLE 4.--Excretion of several organophosphorus insecticides by cattle. 
Hours after treat- 
ment for peak 
excretion 
Percent of 
dosage 
Insecticide recovered in - 
(mg./kg. ) 
Reference 
Ronnel : 
100 Oral >49 5) 18-32 aA 21 
100 do. 86 rf 18-24 12-18 aA 
100 do. 74, 2 4-8 30-36 all, 
Co-Ral: 
37-52 Dermal 3-6 - 120 - 25 
27-65 do. 1-3 - 0-48 - ils} 
10-20 Oral 35-38 34-36 10-12 36 3} 
Dimethoate: 
9-10 Oral YP 4 - - 4 
10 do. 91-95 4-5 3-6 6-30 ils} 
10 Intramuscular 97 al 1-3 9-12 is} 
Ruelene: 
Hal Intramuscular 35 AW) 12-18 24-30 22 
40 Dermal 12 trace 8-12 8-12 6 
Residues.--After 1 to 6 weeks the treated animal is slaughtered, and tissue samples 
are taken for analysis. If any residues: are present, their nature must be determined, 
The time after treatment before meatt of treated animals is free of insecticide and safe 
for human consumption must also be determined. Samples of edible muscles are taken 
as well as of fat where insecticide could be stored. Many of the organs--such as the 
liver, lung, kidney, and brain--are sampled in further attempts to learn more about 
what happened to the insecticide. 
Total residues are determined in all tissues sampled, based on radioactivity. After 
total residues have been measured, their nature must be determined. Data on residues 
will be presented in the discussion of individual compounds, 
FATE OF INDIVIDUAL INSECTICIDES 
Ronnel,--Ronnel (0,0-dimethyl 0-(2,4,5-trichlorophenyl) phosphorothiate), also known 
as Korlan, Dow ET-57, and Trolene, was the first organophosphorus insecticide to be 
approved as an animal systemic. In studies at Gorvallis, Oreg., and Kerrville, Tex., in 
1955 it was observed to be effective against’ grubs:when administered orally to cattle 
(Roth and Eddy 1956, McGregor and Bushland 1956). A dosage of 110 mg./kg. is recom- 
mended for grub control, The compound is now registered for use on beef animals, a 
60-day period between the time of administrationand slaughter being required. Toxicolog - 
ical studies on cattle, sheep, and laboratory animals have been reported (Radeleff and 
Woodard 1957, McCollister, et al. 1959). 
The metabolism of P3%-labeled ronnel in cattle has been investigated by several 
workers, At Kerrville metabolism and excretion in a Hereford heifer and its systemic 
action on screwworms and stableflies have been studied (Kaplanis, et al. 1956). Peak 
levels of the insecticide occurred in the blood after 8 hours and the amount was closely 
correlated with toxicity to both insects. Analyses of the blood showed both ronnel and 
its oxygen analog, but both were dissipated within 60 hours. Of the administered insec- 
ticide, 74 percent was eliminated in the urine and 2 percent in the feces within 3 days. 
164 
