As a Global Leader in Forage and Feed Analysis, we have the unique opportunity to publish some of our data Analytics from time to time. These Tech Notes serve as a canvas to provide our a unique and timely perspective on current analytical trends.
Milk2016 (ALFALFA-GRASS): Index Combining Yield and Quality. Undersander et al. (1993) developed a method for estimating milk per ton of forage dry matter (DM) as an index of forage quality of alfalfa and grasses. The milk per ton index of Undersander et al. (1993) is based on energy content of the forage predicted from acid detergent fiber (ADF) content and DM intake potential of the forage predicted from neutral detergent fiber (NDF) content. The milk per ton index has been used alfalfa variety performance trials at the University of Wisconsin - Madison and by private breeding companies. (Undersander, et al. 1996). The output is included in some forage testing lab analysis results.
Ensiling Management Impacts NDF Digestibility in Hay Crop Silage. (Hoard's Dairyman Article). Hay crop silage making is finished for this year for many dairymen. Typically, it would be months before thoughts turn to ensiling spring hay crop. Now may be a good time to contemplate strategy for the upcoming ensiling season. See the Hoard's Dairyman article HERE.
EDXRF: A New Technology Application for Determination of Minerals in Forage and Feeds. Understanding mineral content of feeds and rations is very important for maintaining long term health and production in cattle. The primary approach to routine forage analysis is by near infrared spectroscopy (NIRS). While this secondary analysis method works well for organic constituents where carbon, nitrogen, and OH bonding exists, most of the minerals that need evaluated are not bonded with these elements and as a result are not able to be analyzed with sufficient accuracy by NIR. It is possible to develop models for minerals with a reasonable correlation to NIR spectra, but the error around the prediction is high.
Small Grains Moisture and Quality Tightly Linked (Hoard's Dairyman article)
It is often a battle with the spring elements to secure a small grain forage crop, and yet it may be strategically important for dairies, especially if they are coming out a winter deficiency in feed. Another use may be to enhance forage inventory to hedge against the risk of a dry summer. Other may employ small grain forages as part of a double crop regiment to maximize dry matter tonnage from limited acreage. Despite the underlying objective, small grain forage can be an excellent feed material, if it is put up correctly.
What can we learn from fermentation profiles? When considering forage fermentation as a measure of forage crop quality, we need to compare it against expected values. Without knowing what is "normal" it is hard to assess a specific report of fermentation quality.
Variable Impact of Feed Fatty Acids in Corn Silage on Rumen Function
Over the last 10 years the fat component of milk has been a key driver for milk price paid to dairyman. The construction of the ration can have a significant impact on milk fat percentage and milk yield. Historically there has been a focus on starch and starch degradability as having a potential negative impact on the ability of the cow to realize higher milk fat production.
Soluble Starch
CVAS is pleased to announce a new starch characterization test: “Soluble Starch”. This assay is part of an evolving investigation spanning a number of years as to how to better understand starch availability and degradability from a ruminant feeding perspective. The Soluble Starch assay helps define fine starch particles that readily wash from the sample. Knowing how much starch rapidly releases into the rumen helps build a more complete understanding of starch degradation differences between samples.
Not Your Ordinary Harvest Harvest is approaching - Tom Kilcer
For many it will be very different from the past. A number
of farms are growing sorghum or sorghum species for the first time. Its harvest timing is
very different than corn silage if you want to get it right. In addition, there was a lot of corn
silage planted in June and July. This corn could be very immature when it is harvested.
Compounding that problem, multiple weather reports are saying that as this is a solar minimum year, cool to cold temperatures will return with a vengeance and the possibility of an
early frost or freeze is above average. With the immature/late planted corn, this is not what
we need. Immature corn silage is a lot like sorghum or sorghum-Sudan. It will be a wet,
higher sugar, low starch forage. Chopping this with a short length of cut, and worse – processing, will produce forage the consistency of applesauce or soup. This is not beneficial to
good fermentation, high milk components, or preserving nutrients (lost leachate is 100% digestible). The good news is that there are steps you can take to minimize these potential
problems.
Apparent Starch Digestibility - How Many Jelly Beans are in the Jar?
A key approach to evaluating the correctness or “integrity” of a forage report is to consider to what degree the dry matter components sum to 100% of the dry matter. On CVAS forage reports for fermented forages, most of the nutritional components are determined either by NIR or chemistry processes. Adding the nutrient components of dry matter should yield a mass balance (sometimes called a “summative index”) within 2 to 3 units of 100. CVAS reports the “Summative Index / Mass Balance” on the lower right of the forage report in the calculations section.
Interpreting your forage report - "Mass Balance"
A key approach to evaluating the correctness or “integrity” of a forage report is to consider to what degree the dry matter components sum to 100% of the dry matter. On CVAS forage reports for fermented forages, most of the nutritional components are determined either by NIR or chemistry processes. Adding the nutrient components of dry matter should yield a mass balance (sometimes called a “summative index”) within 2 to 3 units of 100. CVAS reports the “Summative Index / Mass Balance” on the lower right of the forage report in the calculations section.
Oven versus Microwave: What is the accepted method for forage dry-down?
There has been some degree of obfuscation related to the best method for dry down of forage for analysis in the laboratory. To be clear, we have a dog in that fight. I have spent over 25 years working to improve the quality of analysis and lab services to the feed industry. While recognizing for many years that our use of microwaves for sample dry-down was not ideal, we did it pragmatically as the nutritional industry demanded same day reporting of results on silages.
Dry Matter Determinations: On-farm versus laboratory Why are they different?
Most nutritionists and dairy producers would agree that cows will milk better with a consistent diet. Diet consistency problems often are related to changes in forage dry matter. Frequently, cows experience rumen health issues, run out of feed, or receive inadequate nutrition when the forage weights are not adjusted for dry matter changes. In a USDA research study where the as-fed amount of TMR was not increased with wet silage, there was a significant decrease in milk yield of up to 6 pounds/cow/day.
Clostridia Fermentation During Wet Weather with Elevated Moisture Hay Crop
Will there be enough rain for the crops to grow? Is it going to rain today? These are common questions asked by all producers when planting and harvesting. For the last eighteen months, the answer to these questions has more frequently been “yes”. With higher rainfalls, harvesting at proper dry matter levels becomes a challenge due to the inability to access wet fields. Balancing harvest times for the best dry matter and the best nutrition can be difficult when this happens.
Northeast Weather Conditions to Impact Crop Quality
You don’t need a computer-generated precipitation map to know that it has been unusually wet in the Northeast. In some regions, there is more than a 200% increase in precipitation over normal for the first half of May. At the same time, temperatures in the mid-Atlantic region have been running 1 to 4 degrees warmer than what is typical. This weather scenario sets up the potential for serious forage quality problems.
Understanding your forage analysis
CVAS has put together a document to explain the various report terms that are used in our reports. This document is put together in two sections. The first provides information on newer terms and concepts; the second is a more exhaustive review of analytical terms used in feed testing. This document will provide a quick reference for those experienced in nutrition but not familiar with some of our recent report additions. The document will be good to support those as well that may be new to feed analysis reports and want basic information.