Factors to Concentrate on to Prevent Periparturient Disease in the Dairy Cow With Special Emphasis on Milk Fever

Abstract

Efficient milk production continues to require the dairy cow to experience gestation and parturition each year. The transition from pregnant, non-lactating to non-pregnant, lactating is too often a disastrous experience for the cow. Most of the metabolic diseases of dairy cows - milk fever, ketosis, retained placenta, and displacement of the abomasum - occur within the first 2 weeks (wk) of lactation. The etiology of many of those metabolic diseases that are not clinically apparent during the first 2 wk of lactation, such as laminitis, can be traced back to insults that occurred in early lactation. In addition to metabolic disease, the overwhelming majority of infectious diseases, especially mastitis, but also diseases such as Johne's disease and Salmonellosis, become clinically apparent during the first 2 wk of lactation. The well-being of the cow and her profitability could be greatly enhanced by understanding those factors that account for the high disease incidence in periparturient cows.

Three basic physiologic functions must be maintained during the periparturient period if disease is to be avoided. These are: 1. adaptation of the rumen to high energy density lactation diets to reduce the degree of negative energy balance experienced by the cow; 2. maintenance of normocalcemia; and 3. reducing the degree of immunosuppression that occurs around parturition. Both metabolic disease and infectious disease incidence are greatly increased whenever one or more of these physiological functions is impaired. The etiological role of each of these three physiological factors on the development of each of the common diseases encountered during the periparturient period is discussed more fully in reference.¹⁷ A brief discussion of the etiology of several important periparturient diseases is presented below.