Culling Gone Wrong
Late summer and early fall are times when many producers see a rise in their herd's somatic cell count (SCC). With already low milk prices, the potential loss in premiums because of high SCC is another potential stroke of bad luck.
The quickest way to lower the bulk tank SCC is to cull some cows. Unfortunately, this can also be the most expensive way to lower the herd's SCC. Simply going down the list of a production report and picking high SCC cows and removing them from the herd may not make a substantial drop in your herd's somatic cell count. Depending on the pathogens causing their subclinical infections, a cow's SCC could drop several million cells in a few days without any treatment. The cow with the highest SCC last test day might be close to your herd average by the time you receive your production reports.
AgSource developed the Udder Health Management Package and the Udder Health Management Cow (UHM) Report. To help managers make better culling decisions. To find the right cows to cull, go to Block A on the UHM report. Block A lists chronic mastitis cows, those that have had at least two consecutive tests of at least 200,000 SCC. Rather than culling a cow that inadvertently was tested on the one day she had a high SCC, this list allows the manager to pick out the truly chronically infected cows. Reproductive data is also included along with each cow's "305 ME Milk Ranking" so high producing pregnant cows aren't culled. 
In the example given, Cow 516 is an open cow over 13,000 pounds below the herd's ME 305 lactation average. She has been infected on each of her four test days this lactation and on16 test days last lactation. She is an excellent candidate to ship.
One last caution, culling your way to a low SCC is both ineffective and expensive. Successfully fighting subclinical mastitis infections and lower SCC is a long process. Using culturing services from AgSource to find out what pathogens are causing infections in the herd can help to success-fully preventing new infections.
