STRATEGIES FOR PREVENTING MILK FEVER IN DAIRY-CATTLE

Milk fever is a complex metabolic disorder that occurs at the onset of lactation. Clinical symptoms of this disease include inappetence, tet any, inhibition of urination and defecation, lateral recumbency, and e ventual coma and death if left untreated. The hallmark of this disease is severe hypocalcemia, which probably accounts for most of the clini cal signs associated with a milk fever episode. Several factors have b een consistently associated with increased incidence of milk fever, in cluding parturition and initiation of lactation, advancing age, breed, and diet. Of the various methods used in attempts to control the dise ase, the most progress has been made in dietary management. Until rece ntly, most attention has focused on manipulating the levels of dietary calcium to control milk fever incidence; results, however, have been inconsistent, except for those diets containing very low (8 to 10 g/d) concentrations of Ca. During the past decade, there has been renewed interest and research in the use of dietary anions (Cl- and SO42-) in controlling milk fever. An outgrowth of this research has been the sur prising realization that dietary K is significant (perhaps more signif icant than Ca) in determining the susceptibility of dairy cows to milk fever. This knowledge has expanded the understanding of the pathogene sis of milk fever and has focused attention on research designed to st udy methods for neutralizing the detrimental effects of dietary K exce ss on periparturient animal health. This report discusses various prac tical strategies and potential research areas for managing the dietary forage components to minimize the effects of K on milk fever incidenc e.