It is well known that high Somatic Cell Counts (SCC) within the herd is a reflection of high incidences of mastitis, but could low SCC have a similar effect? SCC is a measure of the cow’s immune response to mastitis causing pathogens. Some researchers believe that low SCC levels could indicate that the immune system is not functioning adequately to fight off infection. If this is the case, what is the point at which SCC becomes dangerously low? Some studies concluded that low SCC increases the risk of mastitis while others found that there was no relationship between the two. Let’s consider the arguments for both cases.
Low SCC is a Risk Factor for Mastitis
If SCC is a reflection of how well the immune system is working, it seems logical that a low SCC before infection means that the cow will not be able to fight off bacteria and is more susceptible to the disease. The generally accepted threshold for healthy, safe milk is 200,000, but this value is only an indicator of the probability that a cow is free from mastitis. Although unlikely, it is still possible for a cow with an SCC under 200,000 to have mastitis.
One study conducted from 1984 to 1996 by researchers from the Netherlands and Cornell University in a single commercial herd of Holstein-Friesian cows found that low herd SCC levels are negatively …show more content…
Another study showed that for every doubling of the SCC, yield decreases by 1.5 lbs. While production decrease is one of the most common effects associated with mastitis, it is surprising that this pattern was found to start at an SCC as low as 12, 500 (Fox, 2013). In addition, there was no difference in the findings when mastitis was caused by major or minor