U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
The "Weak Calf Syndrome" has been gaining wide recognition throughout the north~est and Rocky Mountain regions. The specific syndrome was first noted as possibly being caused 'by a new entity by Dr. Jack Ward in the Bitterroot Valley of Montana after Dr. Ward was unable to relate the observations of necropsied specimens with that of any known published reports. The actual origin of the disease responsible for the specific syndrome noted in the area is not known and may have had its origin elsewhere. However, interest in the problem is increasing in view of the apparent recognition of the disease and acknowledgment of its presence in many different areas.
The problem is particulary devastating when experienced within a herd for the first time, as losses range from 25% to as high as 75% of the calf crop. The initial recognition has been an increase in the abortion rate followed by the calves' inability to rise at birth. The degree of weakness has varied from animal to animal. Many of the calves will be polyarthritic and most die soon after. A few animals are able to survive when immune therapy, blood transfusion, electrolyte solutions, or other fluids are administered. A large number of the animals that survive progress poorly, attaining weight gains of one-half that of their normal counterparts.
Published in Beef Research Program Progress Report (1982) No. 1: 43-44