30 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 195 3 
was eliminated by the sheep 4 week- after the feeding of the insec- 
ticide stopped. On regular diet, residue in the calves decreased to 
5 p. p. in. in > s weeks and was completely eliminated in 20 weeks. 
These results show that the sequence of these insecticides ranging 
from those causing the lowest residues to those resulting in the highest 
residues is methoxychlor < toxaphene < DDT < chlordane < cliel- 
drin. aldrin, and BHC. 
A further study was made at Kerrville in cooperation with an insec- 
ticide manufacturer on the excretion of CS-708 in milk following 
spraying of dairy cows. Sprays containing 0.5 percent of this ma- 
terial were applied to two cows at two-week intervals. The amount 
of insecticide detected in the milk reached a maximum one or two days 
following spraying. The largest amount found was 1.3G p. p. m. 
After two weeks that amount dropped to about 0.3 to 0.T p. p. m., and 
three weeks after spraying was down to 0.24 p. p. m. 
Investigations were continued to determine the extent of storage of 
insecticide residues in the fat of animals and the extent of secretion 
of such residues when the insecticides are applied to animals. In co- 
operation with an industrial company, a special toxaphene emulsion 
concentrate being developed for use as a dip and spray was applied 
to cattle as a 0.5-percent spray at two-week intervals for 12 treatments. 
Biopsy samples were taken at intervals during the experiment, Chem- 
ical analyses of the samples showed that there was no significant stor- 
age of toxaphene in the fat during the first 2 or 3 treatments. After 
11 or 12 treatments the storage averaged about 11 p. p. m., based on 
organic chloride determination. The toxaphene largely disappeared 
from the fat six weeks after treatments were discontinued. These 
results largely confirm previous investigations with similar toxaphene 
formulations. 
Geese Most Susceptible to Aldrin and Toxaphene 
Toxicity tests were run on geese to determine their resistance to 
the insecticides used in cotton fields. Use of geese to destroy weeds in 
such fields is quite widely practiced in some areas. It has been sus- 
pected that such geese may at times be poisoned by the dusts and sprays 
used. Tests showed that oral administration of 10 mg. per kilogram 
of body weight of aldrin and toxaphene will kill geese. DDT and 
BHC caused no toxic reactions when administered as single doses of 
4,400 and 2.000 nig. per kilogram, respectively. Although experi- 
ments could not he designed to simulate exposures that occur in cotton 
fields, the in format ion obtained showed that among the cotton insecti- 
cides tested, aldrin and toxaphene are more likely to cause poisoning 
of geese than DDT or BHC. 
CS— 708 Studied as a Dairy Barn Spray 
Residue studies of CS-708 when used as a dairy spray were made 
in cooperation with the 111:11111 fact urer. Residual Spraying of dairy 
bams with 2.5 percent CS-708 suspension caused little or DO contami- 
nation of milk from cow- subsequently milked in the barns. Limita- 
tions Id the accuracy of the chemical method of analysis prevented 
any definite Conclusions as to the amount of residues, if any, which 
appeared in the milk, 
