Grass Tetany of Ruminants

Publisher Summary A variety of convulsions and paralyses of animals are known as “tetany.” The metabolic disorder of ruminants—that is, grass tetany, has been known for over 100 years. Females are mainly affected, cattle being most susceptible. However, sheep and goats are also afflicted. Grass tetany occurs when cattle or sheep graze grass or small grains forages in cool weather. Pregnant or lactating animals are most susceptible. The primary cause of the disease is low Mg in the forage, but high concentrations of N and K in the forage can be contributing factors too. Other factors that may be involved are low concentrations of carbohydrates and high concentrations of trans-aconitic acid, citric acid, and certain higher fatty acids. The disease may be prevented by Mg fertilization of acid, coarse-textured soils. However, because of higher adsorption capacities of fine-textured soils and lower solubilities of MgCO3 in soils of high pH, higher rates of Mg fertilizer would generally be required in these cases.