Do cows need protein supplement on cornstalks?

Producer Question from 2012

Q.  Do cows need protein supplement on cornstalks? (Oct 3, 2012)

A.  A number of factors can influence whether or not there is a benefit to feeding cows a protein supplement when grazing cornstalks. The following are a list to consider when determining whether or not the feeding of a protein supplement is needed.

  1. Quality and quantity of forage that is available. The amount of grain, leaves and husks in a field will vary with growing conditions. Cattle will select the best forage first when they are initially turned into a field. As a result as cattle graze a field over time, diet quality will decrease. If corn if visible in the manure of gestating cows grazing corn stalks a protein supplement is not needed.
  2. Recent research at the University of Nebraska would indicate that mature, spring calving cows that are in a body condition score 5 or better do not need to be supplemented with protein or energy. Supplement cows with salt and mineral. Bred two-year-old heifers in their third trimester as well as lactating cows will have higher nutrient requirements. These will need both protein and energy supplementation to meet their nutrient requirements.
  3. Weathering of forage. Cool, dry weather conditions in the fall and winter will result in corn residue maintaining quality for a longer period of time. In contrast, wet conditions will result in a faster deterioration of forage quality.

For more information on management of grazing cows on cornstalks or other crop residues, please see the UNL Extension Circular Grazing Crop Residues with Beef Cattle (available for purchase for $2.50 at the UNL Marketplace site).

Aaron Berger, Extension Educator
Panhandle Research & Extension Center
University of Nebraska