Simulated alfalfa winterkill. Submitted photo
Simulated alfalfa winterkill. Submitted photo

Submitted by Melissa Heath, UW Extension - St. Croix County

BALDWIN, WI – Early reports of Alfalfa winterkill and injury are coming in for Northwestern Wisconsin.  A late Spring has also led to a slow green up from many hay fields and pastures, leading to questions on when first crop hay might be ready to harvest.  Cold temperatures and deep snow in late winter caused many dairy and beef cattle to consume more feed than normally expected.  Along with assessing hay inventories, farms feeding corn silage should measure inventories to determine if they will last until new crop harvest.  These circumstances have led to many farmers questioning how to get the most from their limited forage inventories.  

Nutritionally speaking, cattle do not have a hay, pasture, or haylage requirement.  As ruminants, though, they do require fiber for preventing digestive upsets and maintenance of rumen pH.  In the case of lactating dairy cattle fiber also plays a role in butterfat test.  For many nutrients, the NRC (National Research Council) provides guide lines for dry matter intake per nutrient, measured by weight fed, and adjusted for growth stage and lactation.  In the case of fiber, recommendations are much more general.  In addition, judgement calls must be made to determine how much of the fiber in the diet is physically effective.  Physically effective fiber is the fiber that stimulates cud chewing and contributes to the floating mat in the rumen. 

Short forage supplies may force farms to feed reduced forage diets, limit feed, or replace some fiber with a high fiber byproduct feed.  The price and availability of purchasing hay, other forages, or byproduct feeds is a major factor in this consideration.  So is the type of livestock and stage of production.  For example, research with limit feeding for replacement dairy heifers and beef cattle has been successful.  However, limit feeding isn’t an option for high producing dairy cattle.  Likewise, supplementing beef cattle with limited grain can be economical at current prices compared to free choice hay at a round bale feeder.  The UW Beef Information has useful tools for calculating beef cow hay needs and supplementing hay with grain to stretch supplies at fyi.extension.wisc.edu/wbic. An accurate feed analysis and careful ration balancing is required in all cases to ensure nutritional requirements are being met. 

Depending on the stage of production and other ration ingredients, adding a low quality and high fiber forage can be effective in achieving rumen health and extending feed supplies.  The most common examples in the Midwest are straw and baled corn stalks.  Sorting or refusal to eat can be an issue.  Because of that, chopping straw to reduce particle length and incorporating it into a TMR is most effective.  Care should be taken with straw and cornstalks to select bales that are as weed, mold, and dirt free as possible for being used as feed. 

In his 2013 fact sheet “Feeding Strategies When Forage Supplies are Short” Extension Dairy Nutritionist Randy Shaver summarized the feeding characteristics of several high fiber byproduct feeds.  Just a few examples from that summary include beet pulp, cotton seed, cotton seed hulls, soybean hulls, wheat mids, and distillers’ grains.  When looking solely at fiber, coarse chopped straw and cotton seed hulls have the potential to replace the fiber in haylage at a ratio of 2:1.  This factsheet is also a good reference for maximum feeding amounts which should be a consideration for all byproducts, and especially for cotton seed based and distiller’s grains byproducts.  The UW-Dairy Science Management FeedVal tool can be very useful for comparing the relative value and prices of alternative feed products dairymgt.info.  Dr. Shaver’s factsheet is available on the Team Forage website fyi.extension.wisc.edu/forage.

Some feeds may be available only on a seasonal basis.  Sweet corn cannery waste is one such example.  Distance from processing facilities, and thus shipping costs, often becomes the deciding factor if a byproduct feed is competitively priced or not. 

With any alternative feed, take the time to do the math on how much you will feed and how fast it will be fed.  Do you have storage to preserve the feed from the weather?  Is it a higher moisture product that will spoil if not fed in time?  Some products may be offered only by the semi-load or be more competitively priced by the semi-load.  Is this a quantity that makes sense for your farm, or is there potential to work with neighbors in these quantities? 

The University of Wisconsin –Madison Division of Extension has resources to help you assess forage stands, alfalfa health, and manage through winterkill/injury available at the Team Forage website fyi.extension.wisc.edu/forage/altforage or contact your local county Division of Extension Agriculture agent/educator.