One way to improve productivity and efficiency on farms is to simplify management. When it comes to making high-quality milk, Michigan State University’s Pam Ruegg, D.V.M., offered this straightforward piece of advice during the September Hoard’s Dairyman monthly webinar:

“Cull your chronic cows.”

The veterinarian and professor said that cows with a chronically high somatic cell count are prime candidates for removal from the herd. For starters, these cows elevate the bulk tank somatic cell count. Ruegg said it only takes about 5% of cows in a herd with a somatic cell count over 200,000 cells per milliliter (mL) to elevate the bulk tank somatic cell count.

These cows are also likely to have more clinical cases of mastitis, requiring more antibiotic treatments. Cows with higher somatic cell counts necessitate the use of more dry cow antibiotics as well, and these cows also have lower conception rates.

What’s more, they are a threat for infecting other cows.

“The more chronically infected cows you keep in the herd, the more new infections you’ll have in the herd. It’s a self-perpetuating cycle,” Ruegg said.“You don’t treat your way out of chronic cows,” she continued. “You’re not making money on these cows, so think about culling them.”

Which cows would be candidates for departure?

Ruegg advised culling all cows diagnosed with Mycoplasma bovis, chronic Staph. aureus, or Prototheca bovis. If many cows in the herd are affected, that will require a different strategy, but when reasonable numbers are infected, those cows should be removed.

Cows with multiple quarters affected by mastitis or cows with more than two clinical cases of mastitis in one lactation are also animals that could be culled. Likewise, older cows with a history of more than three monthly somatic cell counts over 200,000 cells/mL and cows that maintain a high somatic cell count over two lactations should make a career change, Ruegg noted.

Once more, Ruegg emphasized, “Cull those chronic cows.” To learn more, watch the Hoard’s Dairyman webinar, titled “Gaining a competitive edge in milk quality.” This webinar was sponsored by Boehringer Ingelheim.