According to Todd Duffield, assistant professor within the Department of Population Medicine at the Ontario Veterinary College in Guelph, Ontario, Canada, your herd could be at high risk for subclinical ketosis if:
- More than 10 percent of the close-up cows (three weeks pre-calving) in the herd have a body condition score of 4.0 or greater.
- If the rate of displaced abomasum in your herd is 5 percent or greater.
- If 40 percent or more of the cows have a protein-to-butterfat ratio of 0.75 or less (meaning protein is 75 percent or less of butterfat) at their first DHI test post-calving.
Subclinical ketosis is associated with increased risk of post-calving disorders, such as displaced abomasum, along with decreased milk production and impaired reproductive performance.