This year’s dry conditions have resulted in ranchers feeding lower-quality hay and, in many cases, turning to less conventional forage sources such as corn silage, baled corn stalks or hay from Conservation Reserve Program land. Due to the inconsistency of these forages, Iowa State University Extension agronomist Steve Barnhart and beef program specialist Joe Sellers stress that forage testing is even more important than usual this year. “When testing corn silage, it is best to wait at least 30 days, until ensiling is complete,” Barnhart says, adding that the analysis should include a test for nitrates. “Producers should take a good representative sample from the pile, trench or bag silage storage shortly after feeding is started.”
Due to the severe drought, the USDA released CRP acres for emergency haying this year, and the resulting hay can vary in quality. “The forage types present in CRP are quite diverse, due to seeding mixes used and status of mid-contract management,” Sellers says. “With this diverse plant mix, producers should request that their forage testing laboratory use ‘wet chemical analysis’ tests rather than the near infrared spectroscopy test.” Most laboratories offer both options for forage testing, he said. However, NIRS analyses use calibrations established with more traditional forage species mixtures and may not satisfactorily analyze this more non-traditional mix of forages. Barnhart notes that elevated concentrations of nitrates could be a concern in baled corn stalks or summer annual forages such as sorghums or millets harvested and stored as dry bales, and he encourages testing them for nitrates along with nutrient content.