percent in weight gain without other toxic effects was reported. Turkeys have not been 
found to be markedly affected when fed a ration for 8 weeks which contained 45 percent 
of a toxic meal. 
Feedings of goats, guinea pigs, hamsters, rats, and mice have not shown them to be 
markedly affected except that some showed some depressionof growth rate. None of these 
animals, however, were satisfactory for use as testanimals for the study and the identifi- 
cation of the toxic material (Pritchard, et al., 1956). 
The industrial production of a feed, which is toxic for one species of livestock and 
not for another species, creates dangerous hazards. An important suggestion has been 
made that the mechanism that produces a toxic substance in this type of chemical extrac- 
tion of soybean may produce the same or a similar toxicant in other plants. This sugges- 
tion was made following a feed toxicity in cattle. The toxicity was similar to that caused 
by trichloroethylene-extracted soybean oil meal but was in a herd that had ingested no 
soybean meal nor bracken fern (Eveleth and Holm, 1953). This plant produces very similar 
symptoms and lesions of poisoning. 
Although certain chemicals have a favorable effect on the efficiency of lubricants 
in the mechanization of feed production for livestock, they are finding their way into these 
feeds. Their effect on the composition of milk, meat, and eggs needs to be understood, 
Because of the possible toxicological effects of certain chemicals used in lubricants, 
research on the effects of their use needs to be pursued vigorously to provide the public 
with the facts regarding their effect and the residues they may produce. Lubricants are 
petroleum products. The specific chemical composition of lubricants are trade secrets 
known only to a few of the industrial personnel in key positions of each company. There 
are numerous chemicals used in them, and changes are being made in these chemicals 
in lubricants, new ones are being made to replace others, andnew patents are being ob- 
tained. It has been proved that lubricants contaminate some livestock feeds. So far as we 
know, these lubricants and air pollutants are not causing any livestock illness or death. 
Cancer and other tumors are frequently found in farm animais. The Animal Disease 
and Parasite Research Division has had a small project on this subject for many years 
(Anderson, 1958; Davis, 1939, 1952; Monlux, Anderson, and Davis, 1956, 1957; Monlux 
and Davis, 1953; Sullivan and Anderson, 1958, 1959). In some of these publications 
malignant lymphomas of cattle were reported to occur frequently in this country and 
some recent reports from the Meat Inspection Division indicate they may be increasing. 
The cause is not known. Livestock feedmust undoubtedly get contaminated with carcinogens 
from air pollution because it is impossible to keep livestock hay, grass, and other forage 
from exposure to the air. Some coal tar and petroleum compounds have been found as air 
pollutants which have also been used in experimental production of carcinogenic effects in 
animals (Kotin, 1958). A recent publication in Cancer Research 1959, 19:321-325 (1959) 
reports on the experimental finding of a carcinogenic agent in the urine of cattle which is 
a metabolite of the essential amino acid tryptophan. The British Journal of Cancer 
11:212-228 (1957) gives a report on cancer of the urinary bladder induced in mice with 
metabolites of aromatic amines and tryptophan. 
Highly chlorinated naphthalene poisoning of livestock feeds was another industrial 
contamination in the United States from 1941 to 1953. During this period, there was an 
enormous loss of cattle by sickness and death from a disease of unknown cause, called 
X-disease, or bovine hyperkeratosis. Losses became particularly large in some States 
such as Illinois, Oklahoma, Tennessee, Texas, and Wisconsin (USDA, 1953). The Texas 
Agricultural Experiment Station reported that they estimated 100,000 head of cattle were 
affected in Texas and Oklahoma during the spring of 1953 (Schmidt, et al., 1958). Research 
investigations by the Agricultural Research Service was instigated in 1947 because of 
the rapidly increasing importance of X-disease, or hyperkeratosis of cattle, which existed 
in 27 States. Scientists in 18 States in 1949-1953 conducted cooperative research with the 
Agricultural Research Service to find the cause. They had to study the whole environment 
of the affected cattle--soils, plant life, fertilizers, bacterial flora of the rumen, viruses, 
and livestock feeds. The cooperation and contributions made by many research workers 
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