Haptoglobin as an indicator for diseases during early lactation of dairy cows, with particular consideration of udder health

As an acute-phase protein Haptoglobin ( HP) is part of the nonspecific immune response and represents a strong indicator for inflammatory conditions in cattle. The purpose of this article is to provide an overview of previous study results on serum and milk HP related to diseases in early lactation with special consideration of udder health. During inflammatory diseases of the reproductive tract, metabolism and musculoskeletal system, HP increases in the serum and may serve as a nonspecific indicator for diseases during early lactation. Threshold values are available for the differentiation of healthy from diseased animals. A correlation exists between HP in blood and milk. The HP concentration in milk is not only influenced by systemic disorders, as the udder epithelium is also independently capable of synthesizing HP in case of an infection. In mastitis, HP concentration may be used to estimate the severity of the disease. In addition, HP may provide certain suspicions regarding the causative pathogen. Threshold values for milk HP are available for the differentiation of healthy individuals from subclinically resp. clinically affected animals.