The cost of maintaining a cow through the upcoming winter could change dramatically, according to a University of Missouri Extension agent.

A year-long drought combined with record summer temperatures has greatly affected some of the most common feed for dairy cattle: hay and silage. High levels of nitrates and prussic acid have many producers concerned.

“There are no indicators that something is wrong with your feed on the surface,” said Tim Schnakenberg, an agronomy specialist and co-program director for Stone County Extension in southwest Missouri. “There is no way to tell if your feed is toxic until it is too late.”

High nitrate levels in feed are more common during years when drought conditions have been prevalent. The shorter growing season prevents plants from processing the excess nitrogen applied through fertilizer at the beginning of the season. Nitrogen is built up and stored in the plant with no outlet. Cattle graze and within six hours die due to a lack of oxygen in the blood stream.

Information on feed-testing for nitrate levels can be found at county extension offices in Missouri and elsewhere.

“This year, nitrate buildup has been a real eye opener for dairy farmers in Missouri,” Schnakenberg said. “This year alone, we have lost almost a dozen cattle to feeding on toxic forage.”

Schnakenberg recommends proper hay storage and supplementing livestock diets in order to adjust to the corollaries of the weather.

Bagging hay and feed will prevent loss from high winds. Additionally, supplementing diets with other forage options will conserve hay for the winter months.  

“It is always important to have options for your dairy cattle when it comes to feed,” Schnakenberg said. “Next year is shaping up to be a rough season for rain, as well. It is better to prepare now than to wait until it is too late to do anything.”