Quality forages strengthen the herd
The best advertisement for a herd is the cows themselves, and there are no genetic traits that can outperform poor quality forages. Rebecca Kern, professional animal scientist, Ward Laboratories, Inc., spoke to attendees of High Plains Journal’s recent Cattle U about the importance of analyzing forages, taking proper forage samples and using forage reports for the benefit of the herd.
“It is crucial to be testing your forage,” Kern said. “As plants mature the stem-to-leaf ratio changes. More stems, less leaves can mean less crude protein as it matures.”
Kern highlighted numerous influences on the nutritional content of forages. For some species of forage, over fertilization can cause nitrate issues. If your forage has been rained on, that can mean less protein, less soluble sugars and more fibers. These add up to poor quality forage that cattle then have to put to use as they carry next year’s calf crop.
“If we tested the forage in September but then left it in the field to get rained on, snowed on, damaged by wind and hail then we’re going to need to supplement more than if we had stored it properly,” Kern said.
Proper storage has just as much influence on forages as your chosen sampling technique. Kern explained that you can just grab a handful of forage as a sample but that won’t give an accurate picture of the crop’s quality. To obtain a complete picture, she said, cores should be pulled from 20% of all the bales.
Just because forages are unbaled doesn’t mean the operator should overlook taking a sample. Apply the same principles as when sampling baled hay but when pulling, Kern said, try to “mimic the action of a cow’s tongue.”
If you come across an area of your pasture that hasn’t been eaten there is no need for a sample.
“Look for forages that have been eaten down to the ground,” she said. “Get samples from everywhere they are grazing.”
If the field has draws and valleys, use a zigzag pattern starting from a corner and working on the diagonal.
The sample should represent what the cattle are eating in that particular pasture.
Kern recommends visiting Ward Laboratories’ website at www.wardlab.com or nationalforagetesting.org for more detailed sampling techniques.
Once a representative sample has been draw, it is sent off to the lab. There it will most likely be tested with near-infrared spectroscopy. This means that as a light shines down it will interact with fats, proteins and carbohydrates. These components have different vibrations, causing each to reflect light differently. The reflected light generates a spectra and Kern said, “It is the spectra that is compared to samples that have had wet chemistry methods ran on them. That is how they determine what the amounts of the constituents are in your forage.”
NIRS offers decreased handling and preparation of samples, removing certain levels of human error. If Ward Laboratories is chosen for the analysis, the sample will be compared to other unknown samples in a consortium database.
To view Kern’s full presentation, visit www.cattleu.net.
Jennifer Theurer can be reached at 620-227-1858 or [email protected].
