Ruminants are designed to consume large quantities of forages and turn them into milk or protein. Forages provide fiber that can be broken down by microbes in the rumen and converted into energy. The more digestible the forage fiber, the more energy can be obtained from it. Forage fiber is characterized by several assays including neutral detergent fiber (NDF), undigested NDF (uNDF), and NDF digestibility (NDFd). Neutral detergent fiber is the measure of total fiber and related to intake and chewing activity. Undigested NDF is the measure of the indigestible fiber fraction by an in vitro fermentation for 240 hours and is related to gut fill. NDF digestibility is a measure of the fiber that has been digested after in vitro or in situ fermentation, usually 24 or 30 hours. These measures can be used to predict how well a cow will utilize forages. In times of low milk prices dairy producers need to find ways to reduce costs but not lose production or the health of their cows. One of the most effective methods to reduce feed costs is to grow high quality forages. An article by Pennsylvania State University Extension reported that the difference between a high profit herd and low profit herd was the ability to manage forage quality and inventory, which equated to 9% less in feed costs for the high profit herds. This method does not happen overnight, but with proper planning a forage system can be put into place.
The first step for a forage system is to estimate the quantity of the forage needed to feed your cows for a year and whether your available acres can grow it. This step is vital, as an error here can lead to running out of forage and having to purchase feed. The second step is selecting the forage varieties. This should be in conjunction with your agronomist and nutritionist to make sure the variety or hybrid works well with your soil and provides high quality fiber for your animals. When choosing a crop variety use trials that are most similar to your soil and environment. Use a variety of traits that characterize quantity and quality of nutrient factors that your forage provides. There are traits that do combine both quantity and quality such as NDF and potentially digestible NDF (pdNDF) yields. Ultimately the hybrid needs to provide enough feed for your animals, but also be of high enough quality to maximize intake and production of your cows. University of Nebraska researchers found that high producing dairy cows had a greater response to high NDF digestibility corn silage than low-producing dairy cows. This may mean you have a certain hybrid that provides forages to your lowproducing cows and growing heifers, while the high-producing cows get a hybrid with higher NDF digestibility.
Now that you have selected your crop varieties, it’s important to minimize shrink from the field to the feedbunk. Making sure the silage is at a high packing density will help prevent oxygen exposure during feed out. To minimize loss during feedout Dr. Richard Muck recommends a packing density of 13.2 to 17.6 DM lb. / cu ft. Using a packer attached to the tractor will increase the weight when driving over the bunker or pile and will help achieve a high packing density. Another source of loss during feedout is an uneven face that allows oxygen to penetrate and cause spoilage. One method to reduce this loss is by using a defacer which will keep a clean face on the silage bunker or pile. A defacer will improve dry matter recovery even with a good feed-out rate and high packing density.
As milk prices continue to be variable it’s vital for dairy producers to find ways to reduce expenses, and one of the largest expenses is feed. Forages are a large component of a dairy cow diet, and creating a forage system to match your cows’ need is important for maximizing intake and milk production. Use all the available information from variety trials to gain insight on how well that variety will perform on your land. It will take time to put a forage system into place, but it will reduce feed costs and help weather low milk prices.