Tracking forage quality at harvest, is it worth the effort?
Here at Miner Institute our silage packer Henry takes multiple hand grab samples of each field that goes into the bunker. This is for all cuttings, hay crop and corn silage. We've found value in tracking forage quality (FQ) coming from each field as it goes into the bunk to give us at least an approximation of DM, CP NDF and NDF digestibility. This allows us to better track forage quality as we feed it out without having to poke holes and analyze only the top 6".
Since we fill using the progressive wedge technique, individual fields make up varying proportions of the bunk face at feed out. This leads to more variation in nutrient profiles as we feed through various fields of varying quality. With bunk walls marked every 20', we have a fair idea of where quality changes may occur.
With the myriad fields that Miner Institute crops, on average less than 20 acres and spread out over many miles, soil types and micro-climates; it's difficult to achieve consistent DM and quality. This makes the analysis of each field that much more valuable in assessing overall quality in the silos.
Now that most labs have uNDF (undigested NDF) profile via NIR it will be that much more beneficial to be aware of differences in forage quality. We clearly want to know the 30h NDF digestibility, (aNDFd30) if not for bragging rights then for comparisons between fields and cuttings. As we improve our understanding of uNDF affecting DMI and rumen fill, we can better estimate the maximum level of forage to include in the ration.
We use a simple Excel spreadsheet to compile the forage analyses. Most labs will send results in spreadsheet format to make cut and pasting of the results very easy. We add columns for wet tons, harvest date, cutting and storage unit (Bunker, Pile, Silo ID). We can then calculate yields of CP, and digestible NDF for each field or cutting. Standard agronomic crop management programs don't always allow for nutritional assessments of incoming crop.
Best wishes for your 2016 crop year.
