January 1, by the calendar, is the fresh new start for the year. In reality, though, farmers don’t operate on a calendar basis, we work around the growing season. What is put up during the growing season is what we have to work with until that calendar page says May. Tracking inventory of forage throughout the winter can really give some insight on the use of feed and can help formulate a plan for using up marginal feed and prolonging quality feed without drastic changes to the diets.
There are a few things we need for determining forage inventory. Accurate pile dimensions of what feed is there are critical, but most often, the piece I see guessed at when talking about inventory is density. Rarely can we accurately assess packing density by visual means, but we can certainly measure the density by using a forage probe. If you’ve attended Feeder School, you might have seen us demonstrate the usage of the probe. We can accurately measure density of a pile of feed at various locations and come up with a fairly good representation of what the pile is in terms of density. If you’d like the team to come out to assess density with the forage probe, let us know.
Another way of determining inventory of a pile of forage is by using the “Bunker Silo Density Calculator”, developed by Dr Brian Holmes. This spreadsheet is designed to calculate both as fed and dry matter density of silage stored in a bunker silo. It can be found at https://fyi.uwex.edu/forage/harvest/#inventory and is also available in Spanish. You’ll need pile dimensions, but you’ll also need to know tractor weights used for pushing and packing the pile when it was harvested. The team has truck scales to determine your tractor weights if you’re not sure.
A method discussed during Feeder School training is really quite simple, but requires some note keeping. Producers will mark the walls of a bunk and use feed software or hand track amounts of feed fed during a month to determine density and inventory. This is a very visual reminder to the feeder as they work their way back in a bunk and can be a source of discussion if the pile appears to be disappearing faster than anticipated.
With any of the methods you use to determine your inventory, you can use the fact sheet located at http://www2.dnr.cornell.edu/ext/EDEN/Determining%20Your%20Current%20Forage%20Inventory.pdf to help you through the math. The dry matter capacity of Tower Silos is also included on this sheet.
You can also use the Dairy Herd Forage Inventory Worksheet at https://ansci.cals.cornell.edu/sites/ansci.cals.cornell.edu/files/shared/documents/ForageInvWorksheet.pdf to help you keep track of what is in storage.
Taking it a step farther, you can use the Dairy Herd Forage Needs Workshop https://ansci.cals.cornell.edu/sites/ansci.cals.cornell.edu/files/shared/documents/FeedNeedsWorksheet.pdf and Dairy Herd Forage Needs and Inventory Balance Worksheet https://ansci.cals.cornell.edu/sites/ansci.cals.cornell.edu/files/shared/documents/ForageNeedInventBal.pdf to determine if you will have enough feed or will have to purchase feed to make it to the next growing season based on the number of animals you are feeding on your farm.
If you’d like help determining your forage inventory, give the team a call. We’d be happy to help you define this number. It’s always easier to make changes in forage usage earlier rather than later, and gradual changes are much easier on our cows. Don’t delay – you will be happy to have the information!