Dry cows that eat too much energy for an extended time period don’t fair well after calving, according to research from the University of Illinois.

During one study, researchers offered dry cows a moderate-energy diet ad libitum or restricted to 80 percent of their intake requirement. Cows ate the moderate-energy diet during the entire 60-day dry period. The diet contained 0.68 Mcal of net energy-lactation (NEL) per pound of dry matter.

After calving, the ad-libitum-fed cows had lower dry matter intakes than the restricted-fed cows. They also had higher non-esterified fatty acid levels in the blood and more fat accumulation in the liver, says Jim Drackley, professor of dairy nutrition at the University of Illinois.

Restricted feeding is not advocated on farm. The point is, preventing over-consumption of energy during the dry period can result in a better transition into lactation, Drackley said in March at the Western Dairy Management Conference. Low-energy, high-straw diets are one way to accomplish this.