A new plant-based byproduct of biofuel production is a “viable alternative” to alfalfa meal for dairy heifers, according to research reported last month at the American Dairy Science Association Midwest meeting in Des Moines, Iowa.

Researchers at the University of Minnesota fed a pelleted form of the byproduct, which is produced during production of biofuel from duckweed, to crossbred dairy heifers that were 5 to 6 months of age. Duckweed is a perennial water plant that floats on the surface of water.

The trial consisted of three treatments:

  • Heifers fed the byproduct as a top-dress
  • Heifers fed the byproduct incorporated into their total-mixed ration (TMR)
  • A control group fed a total-mixed ration with alfalfa hay

Here are some of the results:

  • Total gain and average daily gain were similar across the three treatment groups.
  • There were no differences in pen dry matter intake across the three treatment groups.
  • Feeding time was longer for heifers fed the control diet compared to the byproduct treatment groups, but ruminating time was similar between all three treatments.

Although the byproduct is not commercially available, the researchers say it has a favorable nutrient profile for ruminants.

“The most efficient application of this technology would be in arid (climates) where it is difficult to grow traditional plant protein (soy and alfalfa) used in ruminant diets,” says Noah Litherland, PhD, assistant professor of dairy nutrition at the University of Minnesota.

When mixed into a TMR, the byproduct, known as Lemna Meal, also supported heifer growth rates consistent with those advocated by the Dairy Calf & Heifer Association in its Gold Standards II.