Genetic evaluations for somatic cell scores (SCS) haven’t gained the attention they deserve, says George Shook, professor emeritus of dairy science at the University of Wisconsin. To take advantage of this tool, he recommends the following:

  • Use a selection index as an initial screening for A.I. bull selection. Be sure to use the index that is most appropriate for your business goals.
  • Create a “long list” of candidate bulls using the index.
  • Include PTA-SCS among the criteria to help narrow the list. Do not overemphasize SCS to the exclusion of other economically important traits.
  • Designate someone on your milk-quality team to evaluate the SCS score of sires used. Then red-line those with PTA-SCS of 3.3 or higher, and use these sires sparingly when they are truly exceptional for other economically valuable traits.
  • Herds with low average SCC should give the same attention to PTA-SCS in sire selection as herds with high average SCC.
  • Finally, recognize that genetic improvement is a long-term process.