The greatest losses from these diseases are due to faulty 
management and feeding. In cattle bloat, milk fever, acetonemia, 
calving troubles, sterility from endocrine disturbances, and 
chemical poisoning are common. Sheep are also frequently lost 
from bloat, poisonous plants, chemical poisoning, ketosis or 
lambing paralysis, and urinary calculi. 
Pasture-improvement measures that result in a lush growth of 
legumes have increased the losses from bloat; an effort has been 
made to determine these losses and they are included in the tables, 
Recently heavy losses from X-disease, or hyperkeratosis, of cattle 
have been reported in a number of States. Since this was once 
suspected as being an infectious disease, a number of official 
reports on losses due to it were available. 
The increased use of agricultural chemicals, especially insecti- 
cides, herbicides, and fungicides, has directed attention to possie 
ble chemical poisoning as a cause of livestock losses.. For this 
reason and because poisoning of livestock by lead, arsenic, 
selenium, fluorine, and poisonous plants has been reported from 
time to time by the Department of Agriculture and by some of the 
veterinary college clinics, an effort has been made to tabulate 
such losses. 
Nutritional Disorders 
Nutritional disorders of livestock and poultry vary widely in 
nature, distribution, and intensity, and in the resulting economic 
loss. Obviously they are dependent on the feed that the livestcck 
and poultry consume, Nutritional diseases may result from a 
deficiency or excess of a single nutrient or of several nutrients. 
Sometimes they are complicated with other classes of diseases. The 
number of nutrients essential for animal life is large, including 
minerals, vitamins, proteins, amino acids, fats, and carbohydrates. 
Various metabolic and physiological factors, including hormones, 
which regulate body functions, are also involved. Accordingly, 
the number of possible nutritional disorders is extremely large. 
Many are ill-defined or unrecognized. Only a few are well described, 
and their regional or nationwide importance recognized. 
The damage due to nutritional disorders may take the form of 
death, reproductive failure, impairment of growth, or lowered 
productivity of milk, eggs, or wool. The quality of the product - 
whether meat, milk, eggs, wool,or others =- may be decreased. No 
exact figures of total losses are possible, because of the impossi- 
bility of segregating the diseases. Although feeding standards 
have been proposed or established for most clesses of livestock, 
actual requirements for some of the needed nutrients are not yet 
known. Therefore, ideal rationing of animals is not yet possible, 
end there is no standard by which to judge farm production. 
- 139-L 
