SEDALIA – Winter feeding season for beef cattle is rapidly approaching, or in some cases where drought is wreaking havoc with pasture availability, already here. Do you know how your hay or silage supply stacks up nutritionally and why that is important?

Nutrient content of hay, haylage or silage is directly related to the stage of maturity at harvest. Plants conserved for forage become less digestible and have fewer nutrients as they mature. This is true across all plant species. Just because it is “brome hay” or “prairie hay” or some other type of “hay” doesn’t necessarily mean it is better quality than plain old fescue hay. Only a hay test can determine nutrient density and feeding quality.

Forage tests generally cost $20 to $30 dollars, depending on the lab and analysis that is requested. At a minimum, forage should be tested for moisture, crude protein (CP), and acid detergent fiber (ADF). With this information, additional calculations can be made to determine the energy value (TDN) of the forage. Is this investment worth it? Why aren’t “book value” forage quality numbers adequate?

Let’s answer the last question first. For many years, I’ve summarized forage quality values from the forage tests I receive in my office. Extreme variation is always present, but I’d like to use hay test data from 2018 to illustrate this point. For cool-season grass hay samples, the average CP content was 11.5%. That is really good, but the range was 6.5% to 19.9%. For TDN, the average was 54% but the range was from 47% to 67%. With those extremes, average or even book values really become meaningless numbers.

From a feeding standpoint using forage test summary data from a different year, I developed a feeding program for a 550 pound steer gaining 2.0 pounds per day. Using the minimum forage quality values, it was necessary to feed 10 pounds of supplement to

achieve the desired gain. The maximum forage quality sample only needed 2.5 pounds of supplement to achieve the same rate of gain. Underfeeding or overfeeding 7.5 pounds of supplement per head per day will quickly devour the cost of a hay test that can be used to accurately determine the type and amount of supplement needed to meet animal performance targets.

Why go through all the hassle of forage testing and formulating feeding programs based on that information? First, it allows producers to meet animal production and performance goals. That may have a reproduction emphasis for cow/calf producers or meeting target sale weights in the case of backgrounding or stocker operations. Second, it allows these goals to be met in the most economical way possible, based on the feeding capabilities of each operation.

If you have questions on forage sampling or ration formulation, please contact me via e-mail at schmitze@missouri.edu or by calling the Pettis County Extension Center at (660) 827-0591.