Hay Testing for Efficient Winter Feeding

Christine Gelley, OSU Extension Educator, Noble County

As the new year begins, most Ohio graziers are probably feeding a good portion of hay as a part of their animals’ daily ration. Even if there is a supply of stockpiled forage available, we tend to make hay available just in case they need a little extra. It is likely that grain is also part of that daily ration. Well, how do you know how much hay, grain, and pasture they need? No one wants to leave their animals hungry. In addition, we do not want to waste time or money with unnecessary feeding. Figuring out the balance can seem like a guessing game, but the place to start is with a hay test.

Testing the hay you are feeding is well worth the price of sample analysis. Collecting a sample is not complicated and typically, results are available from the lab within two weeks. You can acquire the tools and kits on your own to submit samples, or you can find them at most county Extension offices and often from Soil and Water Conservation Districts. Ag co-ops usually offer sample analysis services as well. Whoever you chose to go through, be sure to select the analysis package that will give you the detailed results you desire.

The package that costs the least will probably still leave you guessing. My typical suggestion is to select a test that will give you values for moisture, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), Relative Feed Value (RFV), and Net Energy (NE). Once you receive the results of your analysis, the challenge of interpreting the values arises. How do you know what values are good or bad?

Your hay test results will list values on a dry matter (DM) and an as-fed basis. Nutrients will appear to be higher for DM basis, because all the remaining water (% moisture) in the hay has been factored out. For CP, values of 8% or greater are usually desired. For ADF, lower is better. Increased ADF values equal decreased digestibility. Neutral detergent fiber is the amount of total fiber in the sample, which is typically above 60% for grasses and above 45% for legumes. As NDF increases, animal intake generally decreases. For TDN and RFV, the greater the values, the more desirable the forage. Net energy is reported in mega calories (Mcal). These values are useful for comparing your forage to other feeds available on the market. Once you have these values compiled you can start formulating rations based on nutritional values of the hay.

First, consider the needs of your animal. Stage of life, current weight, desired weight, and environmental conditions are all important factors. For the sake of an example, let’s assume we are developing a ration for a gestating ewe in her last four weeks of gestation. Currently, she weighs about 175 lbs. Ideally, we would like her to consume 2.5 – 3% of her body weight in DM per day. Now, let’s take a look at a hay test example and assume it is for our hay (see Table 1.1).

Table 1.1:

Sample #: 3rd Cutting
Sample Type Mixed Hay
Moisture (%) 9.09
Dry Matter (%) 90.91
Crude Protein (DM%) 12.36
Fiber ADF (DM%) 42.90
Fiber NDF (DM%) 56.60
TDN (DM%) 58
Relative Feed Value 91
Net Energy (Mcal/100 lb.) 48.2

According to the information from our hay sample and the recommendations from the National Research Council (NRC) for ewes, we could expect this animal to eat about 4.4 lbs. of hay daily. This hay would be adequate for meeting the ewe’s energy needs before pregnancy (maintenance), but it will not meet her demands during gestation. Crude protein is adequate, but energy is lacking. Supplementation will be needed to provide the nutrition she needs.

Our 175 lb. ewe needs 0.44 lb. CP/day and 4.9 Mcal/day in the last four weeks of gestation. If we feed 4.5 lb. of hay it will provide 0.55 lb. CP and 2.2 Mcal. We need to supplement 2.7 Mcal’s with a high energy concentrated feed, such as whole shell corn.

Corn TDN is greater than our hay at 88% and provides more calories (0.61 Mcal) per pound. If we supplement the ewe’s hay ration with 4.5lb. of whole shell corn, we will meet her daily needs (Table 1.2).

Table 1.2:

Feed Type & Quantity Energy Provided


Energy Required for Maintenance (Mcal/day) Crude Protein Provided (lb./day) Crude Protein Required for Maintenance (lb./day)
Mixed Hay:
4.5 lb.
2.2 4.9* 0.55 0.44*
Whole Shell Corn:
4.5 lb.
2.75  4.9* 0.41  0.44*
Total Energy Provided: 4.95* exceeds requirement 0.96* exceeds requirement

This was just one example of how a hay test can help with the development of livestock rations. Recommendations will vary depending on types of hay, time of year, animal species, stage of life, and production goals. With so much possible variation, every little bit of knowledge we can secure is helpful for developing production goals and expectations.

Hay tests may not reveal ideal results and they can vary drastically between cuttings. That is the reality of attempting to manage nature. We can rarely do anything under ideal circumstances, but we do the best we can. As you look ahead to the next growing season and putting up hay once again, do everything you can to efficiently improve forage quality and nutritive value of your stored resources. The better the nutritive value of your forage, the less you will need to supplement and the more money you can keep in your pocket. Testing and formulating rations takes some effort, but once it becomes routine it will come with greater ease.

With that, I will leave you with a quote from Jim Rohn, “Success is neither magical nor mysterious. Success is the natural consequence of consistently applying the basic fundamentals.”

Happy New Year! My best wishes to you and yours for 2018!

Jurgens, Marshall, et al. “Feedstuffs and Formulations.” Animal Feeding and Nutrition, 11th ed., Kendall Hunt Publishing Company, 2012, pp. 87–116.