Bacterial inoculants, alone or in combination with glycerol, may improve milk production efficiency during periods of heat stress, say University of Georgia researchers.

In summer 2008, they fed an inoculant product (Bovamine) for a 10-week period to cows consuming a common ration based on corn and ryegrass silages. A second group was fed glycerol and a third consumed both.

Cows fed the inoculant produced slightly more milk than the control group. Glycerol had no impact on production but reduced milk protein percentage. When fed alone or with glycerol, the inoculant increased the amount of milk produced per pound of feed consumed.