Grass tetany is a complex animal metabolic disorder that is influenced by soil properties, fertilizer practices, forage species and mineral composition, season of the year, temperature, and animal species, breed, and age. The disorder is a major problem of grazing cattle and sheep in the temperate regions of the world. Serious outbreaks have occurred in one-fourth of the states of the United States where losses in affected cattle herds have been as high as 20%. Improved control of grass tetany would result in significant economic benefits to livestock producers and increased production of high quality animal protein to aid the nutritional needs of a rapidly growing world population.
The American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America are pleased to sponsor this special publication of the proceedings of a 1977 symposium on grass tetany. The authors are outstanding animal, plant, and soil scientists who have examined in depth the role and interactions of animals, plants, and soils in causing grass tetany. Research needs and opportunities for improved control of this serious metabolic disorder of cattle and sheep through application of existing research information are considered. Useful new research information from numerous and diverse sources is brought together in the publication.
J. W. Pendleton, President
American Society of Agronomy
V. A. Johnson, President
Crop Science Society of America
P. F. Pratt, President
Soil Science Society of America
Grass tetany is a serious problem of grazing animals in the United States and in many other parts of the world, and costly losses have occurred. In the most common form of the disorder, diagnosis indicates an insufficiency of magnesium—thus hypomagnesemic tetany—but many soil, plant, and animal factors are contributory. Effective methods of treatment have been developed, but, at least in some cases, if these procedures are not initiated soon after onset of symptoms, affected animals will not recover. This is especially a problem with grazing beef cattle, where the first indication that grass tetany is occurring may be finding dead animals. Thus, there is a need for developing a better understanding of all aspects of the disorder, so that through better management practices the likelihood of its occurrence will be minimized.
The six papers in this special publication were presented at a symposium held on 17 Nov. 1977 at the ASA annual meetings in Los Angeles. The symposium was organized by Dr. David L. Grunes in response to a request from Dr. Marcus Zuber.
We expect Grass Tetany to serve as a valuable reference source for both teachers and researchers. We know of no other publication which deals in such detail with soil, plant, and animal aspects of this very important animal disorder. Because many of the factors involved are interactive, some overlap between papers is unavoidable, and, rather than detracting from the publication, is a positive attribute. To have the many contributory factors viewed from the vantage point of different specialties adds to the value of the presentation. The authors were asked to indicate the needs for future research, and the comments they provided in response to this request should offer direction to those who may wish to seek greater insight and new knowledge about grass tetany.
Many people, both members and nonmembers of ASA, contributed to preparing this special publication. The presentations and cooperation of the authors was outstanding. Those who reviewed the manuscripts did so with thoroughness and promptness, and we are deeply grateful to them. They were C. B. Ammerman, University of Florida, Gainesville; R. C. Buckner, USDA, Lexington, Ky.; R. G. Burau, University of California, Davis; R. B. Bushnell, University of California, Davis; C. B. Elkins, USDA, Auburn, Ala.; R. Ellis, Jr., Kansas State University, Manhattan; J. P. Fontenot, Virginia Polytechnic Institute and State University, Blacksburg; R. R. Hill, Jr., USDA, University Park, Pa.; L. R. Rossner, Texas A & M, College Station; W. A. House, USDA, Ithaca, N.Y.; A. W. Hovin, University of Minnesota, St. Paul; E. 0. McLean, Ohio State University, Columbus; J. K. Miller, U.S. Department of Energy, Oak Ridge, Tenn.; M. C. Neathery, University of Georgia, Athens; and R. L. Reid, West Virginia University, Morgantown. Ms. Judy Nauseef and others in the ASA office who may have assisted her contributed much to the quality of the publication by providing skilled editorial polishing and referE)nce checking. Appreciation is expressed for the able and cheerful assistance of the office staff in the Department of Land, Air and Water Resources, University of California, Davis, in particular Ms. Lois Sapp and Ms. Jeannie Jenkins.
Victor V. Rendig
David L. Grunes