Post-harvest gleanings may be tempting for hay-short cattle producers, but producers should approach crop residues with caution, says John Jennings, University of Arkansas forage specialist.

“The hay-crop yield across Arkansas is lower than normal and pastures are grazed short,” he says. “Many producers have started feeding hay, which is putting pressure on the already short hay supply.”

Corn, sorghum, rice, soybeans and cotton harvesting under way in some parts of Arkansas, making crop residue available as an emergency source of hay during drought conditions.

“However, much of the crop acreage is treated with herbicides, fungicides, harvest aids and other chemicals that are not approved for use on forage for livestock feed,” Jennings says. “Producers should find out what crop production or harvest-aid chemicals were applied to a particular field before considering using the crop residue for hay or silage.”

Always check the chemical labels first: Forage restrictions for most crop chemicals are listed in several publications from the University of Arkansas Division of Agriculture’s Cooperative Extension Service.

For herbicides and harvest-aid chemicals, use publication MP44, Recommended Chemicals for Weed and Brush Control. For fungicides and disease control products, consult publication MP154, Arkansas Plant Disease Control Products Guide 2010, and for insecticide information consult publication MP144, Insecticide Recommendations for Arkansas 2010.

These publications are available through county Extension offices as well as at http://www.uaex.edu/.

“If a suitable source of crop residue is located, producers should send a sample for forage quality analysis to determine what type of feed supplementation to use for the specific livestock being fed,” says Shane Gadberry, ruminant nutritionist. Crop stubble is typically very low in forage quality and requires supplementation with other feeds.

Producers can bring forage samples to their county extension office, which will forward them on to the U of A’s Forage Testing lab for a full nutrient analysis. The analysis should include the routine test to determine crude protein, total digestible nutrients and fiber content as well as tests for nitrate levels to make sure the crop material doesn’t contain toxic levels of nitrate.