Relationship between Natural Antibody levels and Somatic Cell Count in Dairy Cattle

At present mastitis in dairy cattle is detected by using somatic cell count and various bacterial diagnostic tests. Still it is difficult to understand the exact health status of the animal by mere observation of the test results, since there maybe presence of sub-clinical cases. There are indications in other species like poultry that natural antibodies might be used as indicators for the identification of (more) disease resistant individuals (Wijga, 2009). The present study focuses on the relationship between the natural antibody titres collected at a single sampling moment and the somatic cell count later inn the lactation. If proven, natural antibodies can be used as indicators for the immune status of the animal. For the present research the preliminary analysis of the fixed effects were analysed using the SAS software and the genetic parameters were estimated using the ASReml software. The results from the analyses show that relationships between the NAb titres and SCS after the sampling moment exists, but with a trend expressing a positive correlated response. The study shows that the NAb levels do not show a protective effect on the animal as the cell counts later in the lactation increased when the NAb levels increased. Hence NAb titre measured in milk samples may not be useful as a tool against mastitis selection