One of the first blogs I ever contributed to the CRYSTALYX^® website was titled “A roadmap to beef cattle winter supplementation”. Though poorly titled, to this day, it remains, by far, the most widely read blog I have ever written. I am not sure if that means I have progressively gotten worse at writing over time or if the topic struck a chord with a lot of people. I prefer to believe it’s the second option — so in this blog, I am diving back into how to best determine what supplements to use this winter depending on the forage base you are supplementing, the status of your cattle and what fits your budget.

“You can only manage what you measure” is on the list of my favorite quotes, as it applies to almost everything in life — and it sure holds up in the context of supplementing cattle. For the sake of this blog, however, it’s not an actual production trait of the cattle you are measuring; it’s the forage you aim to supplement. Forage samples, in my opinion, set the foundation for a cost-effective winter-feeding strategy, which can account for up to 30% of a cattle operation’s yearly costs. For a sample of $15 or so, forage testing is a cheap way to ensure that the money you spent purchasing or putting up your own hay results in the desired quality of forage you intended, and it can also give you direction on the level of supplementation needed to meet the nutrient requirements of your cattle.

The first step to getting the most out of a forage sample is to collect it properly. Outlined below are a few rules that I try to follow when I take samples:

1. Test in “lots,” which are described by in the A roadmap to beef cattle winter supplementation article as “Sampling feeds for analyses" as being “harvested from the same field consisting of similar types of plants, cutting dates, maturity, variety, weed contamination, type of harvest equipment, curing methods and storage conditions.”
2. In each hay “lot,” take samples from approximately 10% of the harvested forage to get an accurate average. It is best to test a few weeks prior to feeding the hay — and not immediately after baling.
3. When testing round bales or big squares, a hay probe should be used to core 12 to 18 inches into the side of the bale to get the most consistent samples. If a hay probe is not available or you are testing stacks or stockpiled forages, etc., samples can be taken by hand. Simply take two or three handfuls from as far within the bale or stack as possible. However, be careful not to strip the leaves off.
4. Once you have taken an appropriate number of samples out of each lot, carefully mix the samples together in a bucket or other mixing container.
5. Put the combined sample into a 1-gallon zip-lock bag and remove any air from the bag before closing it. I try to fill a 1-gallon bag at least halfway full.
6. Label the bag with the lot ID and sample date.
7. Work with your local county extension agent or feed dealer to find the best place to send your samples for testing and analysis.

Once you have all your hay lots sampled and tested, putting the results into a table like the one below will make it easy to identify the differences between various lots.

Organizing the results also allows us to rank our available forages based on different levels of quality, which are determined by the criteria below.

• Low-quality forage: Forages at or below 7% crude protein (CP), with a neutral detergent fiber (NDF) level at or above approximately 63%.
• Medium-quality forage: Forages between 7–11% CP, with an NDF level at or below approximately 63%.
• High-quality forage: Forages that do not require any supplemental CP to meet the needs of late-gestation or lactating beef cows. Typically, above 11% CP.

With these determinations in place, we can strategically determine which supplements are needed to complement both the quality of the forage available and the general nutrition requirements of the cattle being fed. For example, with fall-calving cows at peak lactation or with first-calf heifers, it may be best to utilize your highest-quality hay, as these cattle typically have the highest nutritional needs. Then, supplement with either a mineral product or a lower-protein supplement. On the other hand, it would make sense to feed the lowest-quality hay to mid-gestation spring-calving cows without a calf at their side, and to supplement that hay with a higher-protein supplement to improve digestibility.

Neither hay nor supplements come in a one-size-fits-all package, and without testing your forage, you are guessing at the quality of your hay. As a result, you might be overpaying for excess protein, or you might not be providing your cows with the nutrition they need to perform — and both of those issues cut into your bottom line. By taking forage samples, and by matching your hay to your cows and your supplements to your hay, you can plan for a winter-feeding program that will maximize the profitability of your operation.