Too much flour added to the batter can ruin the entire cake — and the success of the birthday party for which it was intended.

Whether it’s the flour in a cake or the distillers in your ration, if you don’t follow the recipe, it can hurt the outcome. For distillers, that outcome can be milk-fat depression.

Here’s your recipe for preventing a drop in butterfat when feeding corn distillers grains.

1. Feed a consistent product.

Variety may be the spice of life, but when it comes to the nutrients in your cows’ ration, consistency is the recipe for success.

That’s tricky to do when you feed distillers grains. Its nutrient profile can be as unpredictable as a two-year-old, though efforts to change that at the plant level have been proposed (please see “A golden opportunity” on page 30 in the April 2007 issue). This variation can disturb the consistency of the ration. That can be a risk factor for milk-fat depression because it creates an unstable environment in the rumen, says Dave Schingoethe, professor of dairy science at South DakotaStateUniversity.

To minimize the variation that can trigger milk-fat depression, find a supplier that delivers a consistent product and stick with it. Periodically test loads coming from the plant to monitor batch-to-batch nutrient variation. Switch suppliers if load-to-load variation becomes a problem.

The more consistent the nutrient profile of the product you purchase, the less likely you are to encounter rumen problems that can low-ball your butterfat test.

2. Add plenty of forage fiber.

Distillers grains contain 38 percent to 40 percent neutral detergent fiber. That generous level might tempt you to cut back on the forages in your ration. But when forages vacate, you’re left with a ration that has too many short particles and low effective fiber. That’s a recipe for trouble with milk-fat depression.

To prevent this from happening, keep forage at 50 percent or more of total ration dry matter, Schingoethe says.

Consider the type of forage that you include in the diet, too. Fermentability of the diet increases when certain forages, like corn silage, predominate the ration, says Dave Beede, professor of dairy nutrition at MichiganStateUniversity. That can hurt the milk production and components of cows fed diets with increasing levels of distillers grains.

Set a limit on the amount of distillers you feed, too. Most recommendations top out inclusion levels at 20 percent of total diet dry matter. Research studies show this level yields a satisfactory production response without pulling too much forage out of the ration.

3. Mix in other fats carefully.

Distillers grains provide a good source of energy in the diet. Its fat content, which is primarily unsaturated or “free” fat, runs about 10 percent. Though this level and type of fat are not usually a problem for milk fat, there are situations when it can do harm, Schingoethe says.

First, steer clear of a product that fluctuates in fat content. This can happen when the plant is not consistent in the amount of solubles it adds back to the distillers. A batch with 10 percent fat one time and 16 percent another time can be disastrous to milk fat. Find a new supplier if fat consistency becomes an issue.

Second, account for the other sources of unsaturated vegetable oils in the diet, Schingoethe says. Too much unsaturated fat can inhibit rumen microbial activity and reduce milk-fat production.

Make it your goal to keep the total amount of fat in the ration between 5 percent and 7 percent, certainly no more than 8 percent, Schingoethe says.

Apply each step in this recipe and your risk of a butterfat meltdown from feeding corn distillers grains will greatly diminish.