Preliminary results from a forage-test cost-share project indicate that much of the hay being fed to Iowa beef cows is low in quality, says Denise Schwab, Iowa State University (ISU) beef specialist.

The project, launched last fall by ISU’s Iowa Beef Center, is aimed at helping beef producers deal with last year’s poor-quality forages and prevent calving problems. Due to excess rainfall last summer, much of the hay was overmature when harvested and is low in energy and protein.

Project sponsors include ISU’s Leopold Center for Sustainable Agriculture, the Iowa Forage and Grassland Council and the Southern Iowa Forage and Livestock Committee.

“As of mid-January, more than 400 samples had been submitted to Dairyland Labs as part of this project, with about 350 of those samples being conventional beef-cow hay or cornstalks,” Schwab reports.

Roughly 13% of the samples were below 50% total digestible nutrients (TDN) and another 34% were between 50% and 55% TDN.

“While many variables can affect the beef cow’s nutrient requirements, the full feed of these hays would be considered ‘marginal’ to ‘deficient’ in meeting the needs of the average pregnant beef cow during the winter months,” she says. “Another method of looking at forage quality is based on relative feed value (RFV), with 100 being equivalent to full-bloom alfalfa hay. Of the hays tested, 78% were below 100 RFV, meaning there’s a need for energy supplementation in those diets.”

At the very least, Schwab explains, conventional hay feeding programs may not be providing the required nutrients for late-gestation cows, meaning some form of energy supplementation is required.

“If your forages haven't been tested for nutrient content, it’s critical that you closely monitor the body condition of your cows,” she says. “Ideally, each cow would have a body condition score of 6 at calving time to improve the likelihood of her cycling and rebreeding for next year. Keep in mind that first-cutting hay made in June is likely to be deficient in energy for the gestating beef cow and likely would need significant supplementation.”