450 
Journal of Agricultural Research 
Vol. XIV, No. 10 
RATS 
Cottonseed meal, cottonseed flour, and ether-extracted raw cottonseed 
kernels have been fed to rats under comparable conditions. Rats fed on 
extracted kernels have shown superior growth over those on cottonseed 
meal or cottonseed flour. From this fact it is inferred that even in well- 
cooked products there remains something slightly deleterious to rats fed 
on diets containing these as the sole source of vitamines, protein, and 
minerals. Diets containing well-cooked cottonseed products, with a 
small amount of milk powder, appear to be as efficient for rats as the 
control milk diet. 
The degree of toxicity of cottonseed meals depends on the thorough¬ 
ness of cooking in the oil mill. This change appears to be due to oxida¬ 
tion of the gossypol to a substance which we have called “D-gossypol.” 
Some meals may be much more toxic than others, through failure to 
complete this change. Since evidence shows that the gossypol of the 
raw seed may be entirely changed to this far less toxic material, it is 
suggested that the highly toxic effect of the raw cottonseed be described 
as cottonseed poisoning and that injury due to the meal be described as 
cottonseed-meal poisoning or injury. 
Diets containing cottonseed meal with com meal, or soybean meal 
with corn meal, as the sole source of nutriment have led to failure of our 
rats. The addition of calcium lactate, sodium chlorid, and butter tends 
to avert this failure. 
RABBITS 
Rabbits are much more susceptible than rats to cottonseed-meal 
poisoning. They have been very quickly affected by much smaller 
relative amounts of the meal in diets which are apparently adequate 
for these animals. 
poultry 
Aside from an apparently diminished egg production, excessive amounts 
of cottonseed meal have not appeared to be very injurious to hens. 
Some evidence is presented to show that the presence of unchanged 
gossypol in the diet may cause a peculiar discoloration of the egg yolk. 
PIGS 
Pigs have been fed on diets designed to compare the effect of cotton¬ 
seed meals with similar protein concentrates, such as peanut meal 
soybean meal, and ether-extracted cottonseed kernels. 
Unsuccessful attempts have been made to avert cottonseed-meal 
“injury” by supplementing a thoroughly cooked meal with (a) meat 
scrap, calcium lactate, sodium chlorid, and ; butter fat, or (b) 10 per 
cent of skim-milk powder. 
