An investigation of the cause, prevention and treatment of cattle disorders in the Swan River Valley of Manitoba
Cunningham, Hugh Meredith
A disorder of cattle has been known to exist for over forty years in the South-Western portion of the Swan River Valley of Manitoba. This coalition usually occurs during pasture seasons of wet years with the affected animals exhibiting a persistent "pining", or debility. It was found that horses, sheep, and pigs remain unaffected but that young calves and cows in milk are most susceptible. At times the malady has been so severe as to cause as high as thirty per cent death loss in calves and several deaths among mature stock. Very characteristic of the disease is the fact that scouring ceases abruptly if the stock are removed to unaffected areas. Hay from affected fields is usually regarded as "safe" though in some cases such hay has been known to cause looseness and even scouring. Some farmers outside the area attributed the condition to poor feeding practices, but despite good feeding regimes on many farms the disease persisted. Agricultural experts and veterinarians were unable to diagnose the condition or to suggest remedial or preventive measures. Farmers in the circumstances found it economically expedient to reduce their herds or to obtain use of pastures outside the affected area... Members of the University of Manitoba Animal Science Department and officials of the Manitoba Department of Agriculture first became cognizant of these disorders about twenty-five years ago. The findings of Theiler (1924) in South Africa, and Eckles (1930) in Minnesota, had brought to light the existence of a wide-spread-area deficiency of phosphorus in soils and forage, which in turn give rise to a pathological condition in cattle. The clinical symptoms of such a condition in some resects (notably debility) simulate those manifested by cattle in the Swan River area, and hence, the earliest recommendations to allow cattle access to a phosphorus supplement. Following the failure of such therapy either to prevent or ameliorate the condition, various theories as to cause - parasitism, bacteria, water supply, poisonous plants, selenium - were advanced over the years but postulation of causes and application of remedial measures did not result in recognizable abatement of the disease. Thus it became increasingly evident that the problem would not be resolved by any procedure other than an intense study conducted in situ...