Putting Your Best Sample Forward

Analysis can only be as good as the sample that was submitted. For the most accurate results, every effort should be made to ensure that the sample truly reflects and characterizes the material to be analyzed. There are a few things to keep in mind when collecting the optimal sample for submission to the Dairy One Forage Lab, Equi-Analytical Lab Services, or Zooquarius Lab Services.

Sample Representation

Imagine you were in a forest and asked to describe what trees made up the forest. If you selected the tree closest to you, a birch, and stated that all of the trees in the forest were birch trees, you could be missing out on all of the pine trees, maple, ash, or any others in the woods. This is the same if you only sample one bale or select grab samples for analysis. For further information regarding sampling and sample variation, please refer to NFTA sampling guidelines established by Dan Putnam.

A hay probe is the only way to obtain a representative sample from individual bales of hay. Often times you can borrow a hay probe from your local extension office. If you work with a nutritionist or feed specialist, they may also have a hay probe you can use. You may also choose to purchase your own hay probe. The Penn State hay probe is available through our online store or by calling customer support. Use of the hay probe will also require a high-powered electric drill, not included with the sale of the probe.

Sample Size

Having enough sample to analyze is key to proper analysis. The typical sample should fill a 1-quart plastic zip-lock style bag. Drier samples will weigh 75-150g. Wetter samples will weigh 300-500g. If you have any questions regarding the size of your samples, contact us ahead of time and we will work together to develop a plan of action.

Sample Preparation

When submitting wet samples, it is best to freeze them prior to submission. This will help prevent marked chemical changes due to sample degradation should they be held up in transit. Certain exceptions apply dependent upon services of interest – for example, if submitting for microbiological tests (i.e., Yeast and Mold) chill but do not freeze. To ensure speedy and cost-effective delivery of samples, take advantage of our flat-rate UPS shipping labels.

Common Sample Types

The following are some common sample types submitted to our lab. Every sample type is a little different and may require a slightly different process for sample collection and submission. Ensure you are collecting and preparing your sample correctly using our sample collection guides!

We also have sampling guidelines for zoo and aquarium customers using our Zooquarius Lab Services. Though these samples are irregular, proper sample submission is still critical to accurate analysis.

Animal samples

All animal samples must be euthanized prior to submission. DO NOT submit live animal samples.


The largest intact mammal carcass that we can process is an adult rat. Guinea pigs and rabbits are too large. We hope to be able to process samples of this nature soon.


We are not able to process large bones such as cattle femurs or ribs. We are able to process the bones intact carcasses of fish, chicks, or rats, so these samples are acceptable.

For equine customers using our Equi-Analytical Lab Services, please reference the sample guidelines below.