Don’t guess, test: why every field deserves a lab report

This past hay season was a challenge for many producers across Tennessee and North Alabama. Heavy spring rains forced delayed cutting, and rain-damaged fields and rank growth have left many producers scratching their heads regarding the nutritional value of their hay. In times like these, hay testing is not just smart; it’s essential.

Why hay testing matters

You can’t manage what you don’t measure.

Without knowing the quality of your hay — its crude protein, energy, digestibility, or fiber content — you are flying blind when it comes to planning supplementation for your herd. Dry cows might get by on hay with just 7% crude protein, but a lactating cow often needs 11–12%. If poor-quality hay is fed to high-demand animals, you risk weight loss, poor reproductive performance, and open cows come spring. Those problems directly affect your bottom line.

This year’s conditions mean many producers are working with hay that was cut late, rained on, or both. Some bales may barely meet the minimum requirements for a dry cow, and others might fall short even of that. Without testing, you will not know where you stand until it is too late — and by then, cattle performance may already be suffering.

Testing allows you to sort hay by quality and feed your best lots to animals with the greatest nutritional needs. Younger stock, bred heifers, and lactating cows require more protein and energy than mature dry cows. By matching hay to the right group, you can often avoid unnecessary supplementation, save money, and improve herd performance.

When and how to sample

October and November are ideal times to sample hay, once it is baled and stored. Match samples to where hay came from — each field, cutting, or hay lot should be tested separately. Use a hay probe, which is either a metal coring tool that attaches to a drill or is manually inserted into the bale to obtain a core sample. Collect several cores per lot and mix enough in a bucket to fill a quart-sized plastic bag.

Drop the sample off at your local Co-op, where it can be mailed to the appropriate testing lab. Basic tests typically cost between $15 and $45, depending on the depth of analysis. That small investment can save far more in feed costs over the winter.

How to interpret results and act on them

Once results arrive — no matter how dense the data appears — connect with your Co-op feed representative or a trusted nutrition adviser to interpret them. The key numbers to review include crude protein, Total Digestible Nutrients (TDN), Acid Detergent Fiber (ADF), and Neutral Detergent Fiber (NDF). Together, these figures tell you how much protein and energy the hay provides, how digestible it is, and how much fiber it contains.

If hay falls short of your herd’s nutritional needs, you have options. Some producers prefer low-labor supplementation such as liquid feeds or cooked tubs. Others opt for bagged or bulk feed that can be fed daily or every few days. Your feeding program should match your herd size, available labor, and feeding facilities.

One common surprise when testing hay is that the “best-looking” bales are not always the highest quality. Testing eliminates that guesswork and lets you allocate resources where they will do the most good.

Hay quality targets for beef cattle

Match hay to the right class of cattle to reduce unnecessary supplementation

Managing costs through better planning

Testing hay is not just about protecting herd health. It is also about protecting your checkbook. High feed costs can erode profit margins quickly. By knowing your hay quality ahead of time, you can limit supplementation to only those animals and times when it is truly needed.

In some years, you may find your hay is adequate for all classes of cattle without added feed. In other years, supplementation might be necessary to keep cows in good body condition through winter. Either way, knowing early allows you to plan, budget, and buy feed before peak seasonal prices hit.

Simple Steps to Get Started

1. Gather equipment: Borrow or purchase a hay probe. Many co-ops loan them out at no charge.

2. Sample correctly: Take 5–10 cores per lot, mix thoroughly, and bag the sample.

3. Submit the sample: Drop it off at your local co-op or mail it directly to a forage lab.

4. Review results: Work with a feed specialist to understand the numbers.

5. Make a plan: Assign hay lots to different groups of cattle based on need, and determine if and when supplementation is necessary.

Beyond the bale — fertility and future quality

While testing tells you the quality of this year’s hay, it can also highlight long-term management opportunities. Poor forage test results may point to soil fertility issues, especially low potassium or phosphorus levels, or low pH. Soil testing every few years ensures your hay fields can produce the best possible forage.

Replacing nutrients removed with each cutting is critical. Every ton of hay harvested removes significant amounts of nitrogen, phosphorus, and potassium from the soil. Without replenishment, stands can thin, weeds can invade, and forage quality will decline. Applying lime when needed to maintain proper soil pH is equally important — low pH reduces the plant’s ability to take up nutrients, wasting part of your fertilizer investment.

Bottom line

In today’s cattle market, hay is too valuable to leave to chance. Testing hay each season — especially after a weather-challenged year — gives you control over herd nutrition, breeding performance, and feed costs. It is an affordable step that can pay dividends in both animal health and profitability.

Again, you can’t manage what you don’t measure. Hay testing gives you the numbers you need to make the best feeding decisions for your herd this winter.

Zane Troxtel is an agronomist with GreenPoint Ag and serves as pasture and range specialist across North Alabama and Tennessee.