Columnist gives advice on forage sampling

Wednesday, January 13, 2010

Forages are grown, harvested and stored under a variety of conditions that can dramatically affect feeding value. This year, additional moisture benefited forage growth, but made the process of getting high quality hay baled very difficult.

Rain-damaged hay is likely to have much lower energy content than expected. A nutrient analysis is the only means by which to properly establish the feeding value and determine if additional nutrient supplementation is needed.

We are currently feeding lots of hay due to the snow cover, and unfortunately it does not look like it will be disappearing anytime soon. If the cows start to lose weight it could because they are not getting enough to eat or because the nutrient value of hay being fed is not what we think it is.

The best time to take forage samples is as near to the time of feeding as possible. In some cases earlier sampling is needed to help determine supplementation needs and other feed purchases and in other instances to sell at a fair price.

Hay or silage from each field and cutting will be nutritionally different. Hay should be divided into lots based on known differences - location, weather changes, baling day, etc.

A forage lot consists of forage harvested from one field at the same cutting and maturity within a 48-hour period and usually contains fewer than 100 tons of hay.

Sampling is pretty simple with the use of a core sampler. It should be inserted at least 18 inches into the bale at a 90° angle. The butt end of a square bale or rounded sides of a round bale should be sampled; this allows for the most layers or flakes of the bale to be sampled.

Obviously the more samples taken the more accurate the results. A good rule of thumb is to take two cores from ten bales for a total of twenty cores.

The diameter of the coring tool will determine the volume of sample collected in each core. Leaf loss will drastically influence analysis results so be cautious in handling samples so that fine material is not lost. Therefore, when sampling alfalfa and other leafy forages it may be beneficial to take additional samples.

Take all samples from a lot, mix together and place in a plastic bag. A quart sized bag at least three-fourths full or one-half pound is what is recommended. Samples should have excess air removed, be sealed tight and shipped immediately. Make sure to label samples so you can keep good records and match analyses to that lot of bales.

At the Extension Office we have a core sampler and shipping supplies available. You might want to call to make sure the sampler is not on loan before making a trip into town. We ship our samples to SDK Labs in Hutchinson; the cost is dependent on the analysis you want.

This article was adapted from an article written by Sandy Johnson, K-State Research & Extension Northwest Area Livestock Production Specialist.

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Editor's Note: Delta George is a K-State Research and Extension agriculture and 4-H extension agent assigned to Bourbon County. She may be reached at (620) 223-3720.