Counting Cows to Calculate Cow Comfort

Brittany Bowman

Low milk prices and high expenses are tough and seemingly out of dairy farmers’ hands. One factor you can control? Cow comfort.

To measure cow comfort on your farm, simply county the number of cows lying down, says Rick Grant, president of the William H. Miner Agricultural Research Institute in the Sept. 2019 Miner Institute newsletter. That number can be curated into several “comfort indices.”

Cow Comfort Index (CCI) is the proportion of cows in contact with a stall that are lying down and can be a measure of cow lameness. It is the most commonly used index and describes cow’s motivation to enter a free stall and lie down. A well-managed herd would have at least 85% of cows lying down if in contact with a stall, making the ideal CCI greater than 0.85.

In contrast, Stall Standing Index (SSI) is the inverse of CCI, which means it is the proportion of cows standing when in contact with a stall. The ideal SSI is less than 0.15, and anything greater than 0.20 is associated with cow lameness.

Stall Use Index (SUI) describes cow comfort in overcrowded pen scenarios, especially when stocking density is at or above 130%. SUI is the proportion of cows lying down in a pen that are not actively feeding. Herds should have a SUI greater than 0.75, since cows are “wasting their time” idling in alleys. While most complicated to count, it is the perhaps most useful index.

Finally, Rumination Index (RI) describes the proportion of cows lying down (not eating or sleeping) that are ruminating. The target is 50-60%, although it obviously fluctuates throughout the day.

For all four indexes, cows should be counted when they are motivated to lie down, typically two hours before or one hour after milking.