BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 29 
A study of the effect of lindane on the flavor of milk was made. 
It was definitely established that an abnormal flavor exists in milk 
when lindane is fed at high levels of intake. However, it seems highly 
improbable that the feeding of forage sprayed with recommended 
amounts of lindane would cause excretion of enough lindane in the 
milk to produce objectionable off -flavors. 
Toxicological Effects of Insecticides on Livestock Investigated 
Investigations of the toxicological effects on livestock of a number 
of the newer insecticides when applied externally to the animals or 
ingested in the feed were made at Kerrville, Tex., in cooperation with 
the Bureau of Animal Industry. 
When toxaphene was fed at a dosage of 100 p. p. m., storage of the 
insecticide in the fat of sheep reached a level of 22 p. p. m. in 28 days. 
There was no significant increase in toxaphene deposit during the re- 
mainder of the 112 days' feeding period. When feeding of the insec- 
ticide was stopped, the residue dropped about one-half in 4 weeks and 
was eliminated in 8 weeks. The same dosage fed to calves caused 33 
p. p. m. storage in the fat at the end of 56 days' feeding. The storage 
level did not increase above the limit of experimental error during the 
remainder of the 112-day feeding period. After the feeding of the 
insecticide was discontinued the residue decreased to about one-third 
in 4 weeks and was practically eliminated in 8 weeks. 
BHC fed to sheep at a dosage of 100 p. p. m. resulted in the storage 
of the insecticide in the fat to the extent of 120 p. p. m. after 56 days' 
feeding. There was no significant increase during the remainder of 
the 112-day feeding period. When the sheep went on an insecticide- 
free diet, the residue decreased to 32 p. p. m. in 8 weeks and was prac- 
tically eliminated in 16 weeks. 
When aldrin was fed at a dosage of 25 p. p. m. to calves and sheep 
there was a continuous increase in the insecticide stored in the fat to 
the end of the 56-day feeding period. The maximum storage was 
78 p. p. m. for both sheep and calves. When feeding of the insecticide 
was discontinued there was a gradual decrease in the residue in the 
calves to 8 p. p. m. in 32 weeks. Since this appeared to be an excessive 
aldrin content after such a long period, the sheep in this group were 
slaughtered 4 weeks later in order to get larger and better fat samples 
for analysis. Analyses of these latter samples confirmed the previous 
results. 
Although dieldrin was fed at only one dosage, 25 p. p. m. in the diet, 
the amount of storage in the fat of both sheep and calves was practi- 
cally the same as was obtained from feeding this same dosage of 
aldrin. 
No detectable methoxychlor residue was present in the fat of sheep 
or calves after feeding 10 p. p. m. of the insecticide in the diet for 28 
days. Similar results were obtained with toxaphene. 
Ten p. p. m. of DDT in the diet of sheep and calves for 28 days 
caused DDT storage in the fat amounting to 3.1 and 6.8 p. p. m., 
respectively. 
When chlordane was fed at a dosage of 25 p. p. m. in the diet for 
56 days, storage of the insecticide in the fat reached a maximum of 
18.5 p. p. m. for the calves and 12.5 p. p. m. for the sheep. The residue 
