By Nicole Santangelo Carutis and Virginia A. Ishler
Why test?
According to Virginia Ishler, Penn State Extension Dairy Specialist, feeding a forage with lower-than-expected crude protein or fiber digestibility for any length of time on a 100-cow dairy will pay for the cost of a forage test by avoiding reductions in milk production or components. Not knowing the nutritional value of your forages on any size farm adds up over time, costing your farm by overfeeding or underfeeding resulting in poor gains or production. If buying or selling forages, the cost can compound quickly.
Choosing a lab
The National Forage Testing Association (NFTA) certification program monitors the performance of a lab against other labs to alert them of potential problems in their accuracy. Involvement in either of these programs indicates that the laboratory is concerned with the accuracy of its results including quality control sample checks, analytical best practices, trained personnel, equipment calibration, monitoring program, and quality control for improper sampling. Keep in mind that laboratory monitoring practices increase the cost of the analysis. A list of certified laboratories are can be found at the NFTA website or by contacting your local extension office. More information on specifics of lab protocols if choosing a different lab can be found on the Forage Testing Fact Sheet. (Bottom of Form)
How to test?
Collecting a forage sample is simple. You will need a few tools:
- Forage probe – Commercially available for $100-150, if you are crafty you may choose to make your own. Your local extension office may have one also. The National Forage Testing Association has a list of hay probes and where to purchase on their website.
- Power drill or hand brace drill
- Bucket for mixing samples
- Sample bag
- Forage sample submission form from the lab
Consult the lab on how to take a sample or follow the instructions on our Forage Quality and Testing Fact Sheet under collecting a sample . Be sure to avoid spoilage. Do not combine samples from different cuttings or forage types. Label the samples and keep a log of those collected. Store samples in a cool place until submission.
Choosing a forage test
This may seem difficult. Consult with your nutritionist about what forage tests would be most helpful for them to create a balanced diet. If you are balancing your own feeding program you will at minimum need a measure of dry matter, crude protein, fiber, lignin, fat, and total digestible nutrients (TDN) or relative feed value (RFV). Minerals are also important, to prevent major toxicities or deficiencies. Most laboratories will have a basic package that includes these and more.
Forage analysis can help us determine which lot of hay to purchase, estimate value of hay, determine which forages are best suited for which classes of animal groups, and make some basic assumptions about feeding. Beyond this, unless you have trained in nutrition or are well-practiced in ration balancing, it is worth consulting your nutritionist for feeding recommendations.
Source : psu.edu