1st Cutting Forage Quality Update – May 22, 2012

First Cutting Project is being conducted by Cornell Cooperative Extension of Chenango, Herkimer, Madison, Otsego and Schoharie Counties and the Central New York Dairy and Field Crops Team.

This is our fourth and final week of monitoring of 1st cutting for quality in 2012. We hope this information has been of value to you.

All pure and mostly grass stands should have been harvested at this point. Grass stands are beyond the maximum desired 55% NDF for milk production and may be better harvested for lower quality dry hay. Most mixed alfalfa/grass stands should be harvested and we urge that you err on the side of harvesting early if you have any doubts. Alfalfa and mostly alfalfa stands at lower elevations should be harvested. However alfalfa higher elevations are maybe a week away from harvest. Again this is an easy check of alfalfa height before you start.

Another reason to harvest mixed stands in particular is that we are beginning to see considerable alfalfa weevil damage in these stands. Although there is some damage in more pure stands the greater damage seems to come with the more limited number of alfalfa plants for the weevil to feed on in mixed stands. The warm weather of March has moved the development of these insects along as they are also affected by growing degree days (GDD) and there were enough GDDs between late March and the present for them to develop and cause injury. You will notice feeding on upper leaves and you may notice there are only the veins of the leaves left; the leaves appear skeletonized. Break off a few stems and beat them lightly against the sides of a container and the small green larvae with a white stripe and black head will drop to the bottom of the container. Best control is to harvest. It may be good to check alfalfa regrowth for feeding but this is a year we would expect weevil feeding to end soon.

As always use information in the attached table as a guide to know when to harvest by checking your fields! Next and last report will be May 22!
Here are numbers that are helpful when using alfalfa and grass height as an indicator of NDF content: Begin cutting 100% grass stands when nearby alfalfa is 14 inches tall to achieve the desired 50% NDF. Begin cutting 50/50 mixed alfalfa and grass stands when nearby alfalfa is 22 inches tall for the desired 44% NDF. Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall for the desired 40% NDF.

The desired NDF for all grass fields is 50%, 50/50 mixed alfalfa and grass fields is 44%, and pure alfalfa stands is 40%. Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of .8% points and alfalfa of .5% point. Typically NDF increases about 0.8 to 1.2/day for grasses expecting the lower end of that range in cooler weather and the higher end in warm. Alfalfa NDF increases about 0.4 to 0.7/day again figuring the lower end of that range with cool temperatures and the higher in warm. Predictions are adjusted for the coming week’s weather and right now we are assuming normal growth.

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Haylage 2012: Capture Quality, No Butyric No Clostridia

Miner Institute Farm Report Kurt Cotanch – May 2012

Who knows what the 2012 crop year will bring; wet, dry, both…. But we do know that high quality forage is the key to healthy productive cows. One way to maximize forage quality is to avoid or at least minimize butyric acid in hay crop silages. How best to achieve this?

As a research facility we’re occasionally asked to perform product testing of silage inoculants, some with claims of minimizing butyric acid production resulting from clostridial fermentations. To do this we need to be able to create butyric acid silage under controlled conditions to substantiate whether a product can prevent such fermentations. Eric Young and I were designing such a study and inquired with Limin Kung (University of Delaware) on how best to create butyric silage. In our research experience we had not been able to do so. Sometimes the best way to learn how to prevent something is to understand how to create it.

Limin indicated that creating butyric silage in a research setting is very difficult. Why then is it so easy in the field? In Limin’s experience, very wet silage does not necessarily result in butyric fermentations, nor does adding soil to forage. The one factor that did result in butyric acid was delayed chopping or rather prolonged wilting. Wet and dirt alone does not necessarily create butyric acid fermentations, but when combined with delayed harvest, it occurs.

Limin shared some data looking at various products where he ensiled 25-27% DM ryelage in minisilos, either immediately ensiled or delayed for 12 hours after chopping. All test product and control samples had similar pH of about 4.6, with varying levels of lactic and acetic acids, 0% butyric acid and 0.34% NH3 (ammonia) on a DM basis. Under the 12-hour delayed condition, pHs ranged from 5.82 – 6.42, butyric ranged from 0.12-0.22% with NH3 0.90 – 1.04% across treatments. Limin mentioned another study he conducted with alfalfa at less than 20% DM, where there was no butyric acid when immediately ensiled. After 12 hours delay in ensiling, butyric acid levels ranged from 2.05 – 3.13% of DM, NH3 ranged from 0.97 – 1.10% of DM and lactic acid was 0% across all treatments.

The key factor is that the water soluble carbohydrate (WSC) content of the forage is too low after prolonged or delayed wilting stage. WSC are the fuel of fermentation for the desirable lactic acid-forming bacteria. If WSC is too low, clostridia take over. They can break down protein, resulting in butyric acid and NH3. In the lab Limin had to allow the forage to sit overnight for about 12-16 hours before ensiling in order to obtain butyric acid. Plant cells continue to respire after the plant is mowed and chopped. The cells are burning off their WSC the very fuel that we need to properly ferment the forage. In the lab, immediate packing of chopped forage preserves sufficient WSC for proper fermentation. The delay allows for plant cellular respiration to consume the WSC, leaving no sugars for proper fermentation–only protein. In the field harvest delays often result from rain delaying harvest.

In terms of preventing butyric acid when faced with delayed harvest, Limin states that “Nothing Stops It.”

Take-home message to minimize the risk of butyric acid silage fermentation: Chop at proper DM% (32-35%), avoid soil contamination, and above all, avoid harvest delays. If faced with impending wet weather and delayed harvest, it may be better to chop on the wetter side when forage is fresh rather than waiting and losing all water-soluble carbohydrates needed to fuel a proper fermentation. Lastly, if possible, consider segregating high-risk forage rather than spreading throughout the pile or cut the loss and compost.

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1st Cutting Forage Quality Update – May 15, 2012

First Cutting Project is being conducted by Cornell Cooperative Extension of Chenango, Herkimer, Madison, Otsego and Schoharie Counties and the Central New York Dairy and Field Crops Team.

This is our third week of monitoring of 1st cutting for quality in 2012. Grass maturity has increased unbelievably since last week. Orchardgrass is heading out at a much shorter height than we would have anticipated. With that tested NDF values are higher than we would have predicted. All pure and mostly grass stands should be harvested at this point. There may be some grass stands at lower elevations that are beyond the maximum desired 55% NDF for milk production and may be better harvested for lower quality dry hay. Mixed alfalfa/grass at mid to lower elevations should be harvested and we urge that you err on the side of harvesting early if you have any doubts. Begin harvesting alfalfa and mostly alfalfa stands over the next few days at lower elevations. Again this is an easy check for alfalfa height before you start.

Another reason to harvest mixed stands in particular is that we are beginning to see considerable alfalfa weevil damage in these stands. Although there is some damage in more pure stands the greater damage seems to come with the more limited number of alfalfa plants for the weevil to feed on in mixed stands. The warm weather of March has moved the development of these insects along as they are also affected by growing degree days (GDD) and there were enough GDDs between late March and the present for them to develop and cause injury. You will notice feeding on upper leaves and you may notice there are only the veins of the leaves left; the leaves appear skeletonized. Best control is to harvest. Break off a few stems and beat them lightly against the sides of a container and the small green larvae with a white stripe and black head will drop to the bottom of a container. It may be good to check alfalfa regrowth for weevil feeding.

As always use information in the attached table as a guide to know when to harvest by checking your fields! Next and last report will be May 22!

Here are numbers that are helpful when using alfalfa and grass height as an indicator of NDF content: Begin cutting 100% grass stands when nearby alfalfa is 14 inches tall to achieve the desired 50% NDF. Begin cutting 50/50 mixed alfalfa and grass stands when nearby alfalfa is 22 inches tall for the desired 44% NDF. Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall for the desired 40% NDF.

The desired NDF for all grass fields is 50%, 50/50 mixed alfalfa and grass fields is 44%, and pure alfalfa stands is 40%. Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of .8% points and alfalfa of .5% point. Typically NDF increases about 0.8 to 1.2/day for grasses expecting the lower end of that range in cooler weather and the higher end in warm. Alfalfa NDF increases about 0.4 to 0.7/day again figuring the lower end of that range with cool temperatures and the higher in warm. Predictions are adjusted for the coming week’s weather and right now we are assuming normal growth.

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1st Cutting Forage Quality Update – May 8, 2012

First Cutting Project is being conducted by Cornell Cooperative Extension of Chenango, Herkimer, Madison, Otsego and Schoharie Counties and the Central New York Dairy and Field Crops Team. 

This is our second week of monitoring of 1st cutting for quality in 2012. Warmer weather and significant rain have moved the maturity a long across much of the region. Pure or mostly grass stands at lower elevations (below 1000 feet) need cut at this time. At higher elevations the prediction would be we are still a week away from grass harvest. Pure to mostly alfalfa stands appear to be 2-3 weeks away from harvest. Because alfalfa has been set back by frosts in some fields usually at higher elevations, weed competition is greater than normal; in particular dandelion but winter annuals as well. At this point it appears this competition is having an effect on the alfalfa.

As always use information in the attached table as a guide to know when to harvest by checking your fields! Next report May 15!

Most locations have alfalfa and grass height measurements, but a few only have grass and some only alfalfa so you may see blank spaces in the tables. At some locations the alfalfa is really too short to fit the equations, under 13 inches, so you see “Too Early” indicated. If a farm has harvested you will see “Cut” indicated. If you want to do it yourself check http://www.forages.org/joomla/index.php/tools for Excel spreadsheets that will make predictions of current NDF content in the field from your own measurements. Our feeling is that many times these calculations are within the error of scissor cut or grab sample results sent to a lab so you are encouraged to make your own measurements.

Here are numbers that are helpful when using alfalfa and grass height as an indicator of NDF content:

Begin cutting 100% orchardgrass stands when they are 19 inches tall and 100% reed canary grass stands when they are 21 inches tall for the desired 50% NDF. In general we say 100% grass stands should be cut when nearby alfalfa is 14 inches tall to achieve the desired 50% NDF.

Begin cutting 50/50 mixed alfalfa and grass stands when nearby alfalfa is 22 inches tall for the desired 44% NDF.

Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall for the desired 40% NDF.

The desired NDF for all grass fields is 50%, 50/50 mixed alfalfa and grass fields is 44%, and pure alfalfa stands is 40%. Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of .8% points and alfalfa of .5% point. Typically NDF increases about 0.8 to 1.2/day for grasses expecting the lower end of that range in cooler weather and the higher end in warm. Alfalfa NDF increases about 0.4 to 0.7/day again figuring the lower end of that range with cool temperatures and the higher in warm. Predictions are adjusted for the coming week’s weather and right now we are assuming normal growth.

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