During this time of year, many producers are hauling hay to their storage lots to use for winter. On top of this, they are also pricing and buying any additional hay that they may need. It seems everyone has it figured out though they may not be aware of problems lying just below the surface.
A significant problem for producers is that there is an extensive range in hay quality depending on many conditions. Things like the level of maturity, fertilization, growing conditions, harvest conditions, and storage methods all play a part. Accurately sampling and testing hay is the only way to get an accurate understanding of the nutritional value of your hay.
The nutritional value is not really something you want to guess at. Using values from previous years or a “book value” can be costly since a producer may incorrectly develop a ration using values that aren’t even present. Here are some tips to follow in order to get an accurate hay sampling.
Guideline for Hay Sampling
Getting a representative sample is a critical first step when hay sampling. Samples must accurately represent the entire lot of hay you are going to use. When you are getting a sample for analysis, it should be kept separate from other lots of hay. The UNL NebGuide “Sampling Feeds for Analysis” says that a lot of hay should be harvested from the same field containing similar types of plants. The cutting dates, maturity level, variety, weed contamination, type of equipment used, curing methods, and storage conditions should also be similar. Whenever these conditions are different, they should be separated and sampled as another “lot.“
Use a hay probe or core sampler.
It would be best to use either a hay probe or a core sampler to get to the correct part of the bale when sampling hay. The hay probe should penetrate the bale at least 12-18 inches. In order to get an accurate sample size, the probe should have an internal diameter of 3/8 of an inch. Using your hand to grab a sample will only sometimes provide you with reliable results.
Tips of the hay probe should be kept sharp to cut through the hay and prevent selective sampling. Avoid getting the hay probes hot when a drill drives the probe into the bale. The heat is because friction from high speeds can heat the probe to a point where it damages the hay sample.
Select a number of bales from each lot.
To get a representative hay sample from a lot, select 15-20 bales in the lot. Knowing the total number of bales that are present can help identify a random method that could be used. Such a method could be collecting a sample from every 4th bale in order to obtain an accurate sample.
Once all of the samples for a lot have been collected, it may be necessary to sub-sample what you have. A sub-sample is needed to get the feed down to a sample size that can be analyzed. The guide I linked above will walk you through a step-by-step process to do this. Ensuring that the sub-sample you submitted represents your lot is essential.
Store sample correctly
Once the hay sampling is done, store them in a plastic sealed bag in a cool, dry place until it is ready to be submitted. If your samples contain over 15% moisture, they should be frozen. Freezing the sample prevents the moisture from breaking the hay down and not giving you an accurate reading.
Make sure to label the bag with your name, address, lot identification, and feed type. Most commercial labs will provide an information submittal form that allows producers to select a standard feed test for forages. Send samples into the lab early in the week to avoid having the sample sit over the weekend.
What to Analyze
Analyze for moisture, protein, and energy.
Cattle feeds should be analyzed for moisture, protein, and energy. Producers may also want to have their forages tested for crucial minerals as well. Feed sample results are usually reported on an as-is and dry-matter basis.
When developing a ration for cattle or comparing feeds to one another, always use a dry-matter basis. Since types of feeds will have different moisture content, this will give you a more accurate comparison. After you have formulated the ration, you can then convert it to an as-is basis using the moisture content of the feed. Converting the formulation will tell you how much feed you will actually need to use.
Analyze forages for nitrates.
Things like moisture, protein, and energy may not be all that you need to analyze. Annual forages harvested for hay like oats, Sudan grass, and sorghum-Sudan hybrids should be examined for nitrates.
These annual forages can accumulate high levels of nitrates under various growing conditions that can potentially reach toxic levels. The only way to know if high levels of nitrate accumulation have occurred is to test for it. I discussed the issues with nitrates in my last post, “How to avoid nitrate toxicity following a drought”.
Pay attention to hay storage.
Though a lot is covered on how to get your hay samples and how to have them tested, there is not usually enough emphasis on hay storage after. If they are not correctly stored, hay bales can lose up to 50% of their nutritional value through improper storage.
I went over in the previous post, “5 Rules for Proper Hay Storage,” the ways that you can go about making sure that your bales will retain as much of their nutritional value for as long as possible. Here are some cliff notes:
- Make sure that the bale is packed tightly
- Place bales under a roof if possible, or cover them with a tarp
- Store them on an elevated platform or on crushed rock
- Put the bales in a north-south direction with plenty of space between rows
- If possible, feed the oldest bales first