“Testing forages is one of the most undervalued tools at our disposal. That is especially true for beef cattle and small ruminants, because fewer of those producers utilize it compared to dairymen. You simply can’t come up with the correct feed ration if you don’t start with good values for nutrients.”
That’s how Nick Minton sizes up the value of forage testing — and specifically, testing silages, haylage and baleage. Minton is a Purdue Extension animal scientist and coordinator of the Indiana Bull Evaluation Program at the Feldun-Purdue Ag Center near Bedford, Ind. He oversees performance testing of two sets of beef bulls each year.
The goal is to test forages so you know how to supplement for optimal performance, Minton explains. The type of animal you are feeding, whether a lactating dairy cow or a gestating beef cow, determines part of the feeding equation. But nutrient values of forages at your disposal decide the rest, and you can’t know that without accurate testing information, Minton says.
Forage sampling tips
Here are five tips for obtaining representative samples of forage for testing:
1. Obtain good samples. Grab samples are OK for silage or haylage in bags, piles or silos as it comes out of the conveyor. Minton recommends pulling 10 to 15 grab samples to form one composite sample. The final composite sample should be around 1 pound. Some labs charge more if you send 2 pounds, and 1 pound is sufficient, he explains.
If you’re sampling baleage in a bale, use a forage probe to collect no fewer than 20 cores. Probe perpendicularly to layers or flakes. Again, submit 1 pound of sample material to the lab.
2. Pull samples at the right time. Normally, Minton recommends taking your first sample on the day of harvest. That will clue you in as to what general values to expect. Then, take a second sample after ensiling. “Wait until you have the ends off; then take grab samples from the face,” he says.
3. Cover holes in plastic properly. If you’re sampling baleage or any forage in a bag before opening it, cover any holes formed during testing with silage tape, not duct tape. Silage tape is designed to keep oxygen out, Minton notes.
4. Recognize special situations. If the forage was unusually wet or dry at harvest, you may want to pull a second sample before you open the pack, pile or bag, Minton advises. And if you suspect that you might have a problem because the forage was too wet or too dry, consider paying extra for wet chemistry tests vs. typical NIR analysis performed by most labs. “If there are concerns about potential mycotoxins, a wet lab test could be worth it,” he says.
5. Analyze the results. Look at dry matter values, not as-fed values. Besides crude protein and neutral detergent fiber, check out relative forage quality. Similar to relative feed value, RFQ, developed by the University of Wisconsin, tends to be more accurate if fiber digestibility varies from normal and if the forage includes grasses.
The World Forage Analysis Superbowl uses RFQ as a trait for judging in its contest, held at World Dairy Expo. Pounds of milk produced per ton is also a composite measure used in the World Dairy Expo contest results, geared toward dairy producers.
Can you pick out the best forage from World Dairy Expo? Click through the slideshow of samples and then check out the table in the final slide to see the actual nutritional content of these samples.
About the Author
You May Also Like