supplied through cottonseed meals containing various amounts of this ingredient. No 
symptoms or lesions of gossypol poisoning were produced, and growth rate was not re- 
tarded (U.S.D.A., A.R.S., 1952). The method of producing low amounts of free gossypol 
made the feed satisfactory. Some cottonseed meals were found toxic. They produced death 
from free gossypol poisoning. 
Nonruminants, young ruminants, and poultry are most susceptible to gossypol 
poisoning. The ARS Southern Utilization Research and Development and the Animal 
Husbandry Research Divisions andcertain contracts for research did much on the problem. 
They developed analytical methods of determining the amounts of free or toxic gossypol 
in feeds; by use of dilutions of cottonseed meal containing 0.04 percent free gossypol and 
feeding tests on chickens. They determined that 0.016 percent free gossypol was the maxi- 
mal safe level that could be included in the total diet for starting and growing poultry 
without harmful effects. Cottonseed meals of low free gossypol are now being made. 
It was established in 1916 that trichloroethylene-extracted soybeanoil meal was toxic 
to cattle, but that other meals produced by extraction with other chemical solvents were 
harmless (Stockman, 1916). A few years after it was first proved in Europe to be poison- 
ous, extensive losses from 1923 to 1925 were experienced in Germany and Holland from 
this poisoning. Many reports showed that heavy losses from soybean meal extracted with 
trichloroethylene occurred in Iowa (1947-1952), Italy (1948), Colorado (1949), Kansas 
(1951), Minnesota (1951), Mississippi (1951), South Dakota (1951), Japan (1951), North 
Dakota (1952), and Hawaii (1952). A hemolytic toxic substance was demonstrated in the 
meal (Twiehaus and Leasure, 1951). In Minnesota, 38 of the herds studied were dairy 
herds and 6 herds were feeder steers (Pritchard, et al., 1952). The Agricultural Research 
Service in cooperation with the Iowa and Minnesota State Universities conducted studies 
of the chemistry and extraction processes and on the toxicity of various experimental 
trichloroethylene-extracted meal (TCESOM) products for farm and laboratory animals. 
The TCESOM meal was voluntarily withdrawn from the American market by the manu- 
facturers concerned in 1952, because some of it produced a form of aplastic anemia in 
cattle after continued feeding and had toxicity for sheep and horses. 
The solvent extraction processes leave only about 1 percent oil in the meal whereas 
the older hydraulic process and expeller process leave about 4 percent oil in the meal. 
The hydraulic process and the expeller process donot produce a toxic meal for livestock. 
The solvent extraction process does not produce a toxic product if hexane is used instead 
of trichloroethylene. However, the hexane process is more expensive, it has the fire 
hazard and requires more labor. 
Cattle, horses, and sheep are susceptible to the toxic effects of this type of extracted 
meal and show acute andchronic forms of aplastic anemia. Symptoms in cattle in the acute 
form appear after 1 to 9 months of feeding and consist largely of high fever, hemorrhage, 
and deathin5to 10 days.Inthe chronic form, the animals gradually lose condition, become 
anemic and weak, and eventually die after a course of illness involving several months in 
which little or no hemorrhage occurs. Cows that received 1 to 3 pounds of the toxic meal 
daily have died. Calves that received 1/4- to 1/2-pound daily have also died. In some 
instances, it took 1 poundof the toxic meal daily and 1 to 1-1/2 years to produce symptoms 
and death. The toxic substance appears to bemostly in the water-soluble fraction. Residual 
trichloroethylene in the extracted meal is not responsible for the effects noted (Pritchard, 
et al., 1956). Sheep losses from this meal have been associated with lambing, surgery, 
and a **trigger mechanism”’ such as pneumonia ormechanical injury (Holm, et al., 1953). 
Swine feedings have not shown the swine to be markedly affected. No ill effects were 
shown from limited feedings of weaned gilts throughtheir period of growth, reproduction, 
and lactation, and the feeding of their offspring to market weight. However, this does not 
give sufficient proof that it is nontoxic to swine (Pritchard, et al., 1956). 
In a ration containing 22 percent toxic meal fed baby chicks for 50 days there was 
a 26 percent mortality against a 4.6 percent mortality in birds fed the same amount of a 
meal processed differently (Eveleth, et al., 1953). In other chick feeding a loss of 10 
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