Forage test to compose in nutrition | State

Adapted from “Sampling Bales for Forage Quality Analysis”, Dave Hartman, Penn State Extension; and “Sampling Hay and Silage for Analysis,” Dan Undersander et al., University of Wisconsin-Extension.

Experienced farmers can often tell whether hay or silage is “good” or not by smell, color, presence of weeds, texture, particle size, etc., and most have details they look for in every lot they buy.

However, regardless of experience level, more accurate data on the quality of your forage will help you create the best ration for your animals to increase profitability. It can also help prevent and diagnose animal health problems related to mycotoxins. The best way to get this information is to sample your forages and send them to a lab for analysis.

Before collecting samples, decide which laboratory to use. There are several commercial labs based in Pennsylvania and surrounding states that test forages. Contact this lab in advance so they can send you a submission form. You can then specify the test options you need.

Alternatively, you can access certain lab submission forms online. Complete and submit the submission form with your sample. You can also have test results mailed to individuals or

companies you work with on livestock nutrition. If you do not know which test(s) to request, contact a person competent in animal nutrition.

How to sample forages:

Just as with soil, manure, or water, useful lab results come from good sampling.

To sample bullets, use a corer. You can buy a corer, but check with nearby farms, feed distributors and extension offices first, as they are often available for hire. Most coring rigs are designed to attach to a power drill.

You should sample bales separately from different forages, from different fields and from different cuttings from the same field. In other words, consider each cutting in each field as a separate lot (in most cases).

Round bales: core towards the center of the bale from the curved edge.

Square bales: Core from the end of the bale to the middle of the bale.

Wrapped wet bales: Sample before or after fermentation.

Big Balls: Sample at least 10 balls.

Small Balls: Sample at least 20 balls.

Mix the hollowed out samples in a clean bucket. Then take a subsample of that composite to send to the lab.

For silage, it is easier to sample at harvest than to sample the ensiled material as it is fed. Plus, your results are available before forage is distributed to allow for more accurate balancing of rations and time to purchase supplements. But, if you must sample silage, sample accordingly.

Silage silage from the tower: do not take a sample of spoiled silage from the top of the silo; collect 1-2 pounds of silage from the unloader while it is running, taking samples from the morning and evening feedings of the same day.

Silage from the bunker: do not take a sample of spoiled silage from the top of the silo; take several handfuls of different vertical layers from the face of the silo after the feed days have been removed, and the forage is freshly exposed, totaling about 2 lbs.; combine handfuls in a clean bucket and mix well.

Zippered plastic bags work well to hold the forage sample. Consult with the lab of your choice to find out the sample size they need to perform their tests.

Mail wet samples of wet bullets early in the week so they get to the lab as soon as possible.

Squeeze the air out of the sample bag and close it properly. Forage that has undergone adequate fermentation should have enough acid to preserve the sample during transport to the laboratory. Freeze wet fodder that has not been fermented beforehand and send it in an insulated container.

Results interpretation :

Reading forage test results can be a confusing alphabet soup. Adding to the confusion, each class of livestock has a different ideal range of values ​​shown on a forage analysis report, such as crude protein, acid detergent fibre, neutral detergent fibre, starch and minerals. .

For this reason, it is helpful to seek the advice of people who have expertise and experience in animal nutrition to review the results with you.


Penn State College of Agricultural Sciences’ research and extension programs are funded in part by the counties of Pennsylvania, the Commonwealth of Pennsylvania, and the United States Department of Agriculture.


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