– Dr. Jeff Lehmkuhler, Extension Beef Specialist and Dr. Ray Smith, Extension Forage Specialist, University of Kentucky
One should not complain about spring rains, but when it begins to interfere with hay making, the gloves are thrown off and it is go time. This seems to be the case every spring in the Bluegrass state. The spring rains helps the cool-season forages grow, but it impedes our field work. Since we can’t control the weather or the forage from maturing, we have to dig deeper into the toolbox to find some help. Harvesting high moisture forage as baleage may be the tool of choice for some. Several folks have called about wrapping annual cereal grain forage this spring. Let’s talk a few minutes to cover some basics so any forage made as baleage this summer has the best chance of resulting in a high quality winter feed.
- Forages need to be cut at the boot to early flower stage for optimum quality. This helps ensure adequate soluble carbohydrates for the microbes to ferment and drop the pH to preserve the forage.
- Forage should be baled at the proper moisture, 40-60%, to ensure a successful fermentation. Higher levels of moisture increases the risk of a clostridial fermentation and botulinum growth. Too dry impedes fermentation and again to lead to a poorly preserved forage. Obtain a windrow moisture meter, bale moisture probe or utilize the microwave technique for determining moisture levels in forage.
- Slow down the tractor speed when baling to ensure a tightly wrapped bale is made, particularly with cereal grain forages. It is important to limit the amount of air or oxygen so that anaerobic fermentation occurs soon after baling.
- Wrap bales in plastic ideally within 6 hours of baling to limit air and oxygen exposure. Stretch film should be applied to provide 6 millimeters of plastic thickness. This is often accomplished by having 6 layers of plastic. At a minimum 4 layers of plastic should be applied, but 6 millimeters is recommended to limit oxygen from getting through the plastic.
- Allow the bales to ferment for 4-6 weeks. Samples should be obtained and analyzed for pH and ideally a fermentation profile which will provide the level of acids in the silage. This information is important to help determine the quality of silage made and whether there is a potential risk for a disorder.
There are thousands of bales made for silage annually with few cases of botulism or listeria occurring in animals. The key to lowering the risk of poor fermentation is following the five basic steps outlined above. For additional information on making baleage, please contact your local county Extension office.
Microwave Oven Method to Determine Moisture Content of Hay, Silage and Baleage
The microwave oven method provides reasonably accurate forage moisture results in a relatively short time. Although this method takes about 20 minutes to complete, the measured moisture concentration is much more accurate than those from electronic conductance moisture testers, especially for high moisture sample like silage and baleage.
Before using the microwave oven method, obtain the following items:
- Microwave oven
- Scale (must weigh in grams-can buy one from most post offices)
- Microwave-safe plate
- 10- to 12-ounce cup of water (a coffee mug works best)
- Pencil and paper
Use the following procedure for the best results:
- Obtain a representative forage sample (whole plant material).
- Cut the sample into 1-inch pieces; keep leaves and stems uniformly mixed.
- Weigh the plate and record it as “plate weight.” This will be subtracted during the final calculation.
- Add approximately 100 grams of the forage sample to the plate; spread the sample as uniformly as possible.
- Weigh the plate with the forage sample and record it as “initial weight.”
- Place the cup of water in the corner of the oven to capture unabsorbed microwaves as the plant tissue dries. This prevents sample from igniting.
- Place the sample on the plate in the center of the oven.
- Set the oven on HIGH for 2 minutes* and “cook” the sample.
- Remove the sample and plate, weigh them, and record the weight.
- Change the water in the cup to prevent the water from boiling over.
- Set the oven on HIGH for 1-2 minutes* and “recook” the sample.
- Remove the sample and plate, weigh them, and record the weight.
- Repeat steps 7 through 10 until the weight does not change more than 1 gram (this means the sample is dry); record as “final weight.”
- Use the following equation to determine the percent of moisture of the forage sample:
Percent moisture (%) = (Initial weight – Final weight) x 100 divided by (Initial weight – the Plate weight)