Managing Mud on Dairies
Adapted by Dr. Michael Payne - Director, CDQAP
Now is the time to manage corrals to reduce mud before El Niño is upon us. Relatively little research exists on the effects of mud on dairy cattle, but in one relevant study researchers estimated that for every inch of mud, dry matter intake (DMI) is reduced by 2.5%. This observed correlation between increasing mud and decreasing DMI should predict a concurrent decrease in milk production. In fact, in a separate University of California (UC) study, there was a significant association between increasing precipitation and reduced test day milk, particularly for dairies where cows were housed outside without shelter.
Cows will be more reluctant to make their way to the feed alley if they have to walk through mud. When they do walk to the feed apron, depending on the depth of the mud, they can expend significantly more energy doing so. Cows also require increased energy requirements if forced to lay in wet environments and cows will spend less time laying down altogether. During research conducted by UC, cows even preferred to lie on concrete rather than in muddy areas. Reluctance to transverse muddy areas may lead to cows eating fewer and larger meals (slug feeding) which may increase incidence of rumen acidosis, laminitis and displaced abomasums. Mud and lack of cleanliness associated with wet environments has been linked to increases in mastitis and metritis. Wet conditions contribute to softer hooves and an increase in lameness.
Corral Management to Prevent Mud
General- Most corrals can be maintained at a minimal cost using some basic practices. In particular and as described below, diversion of outside rain water and regular scraping can typically be performed with existing equipment and labor. Most mud problems can be managed simply by creating adequate slopes and drainage and regular manure removal. For many dairies, soil stabilization with wood chips, gravel, road base, fly ash, concrete etc., may only be required in high-traffic lanes, feed alleys and around watering troughs.
Corrals can be managed to prevent mud, but correcting mud problems can be difficult if not impossible during the winter, after the soil has been saturated by rain. For that reason it is important to repair, resurface, re-slope and re-compact the corrals during the dry months. A useful mindset reported by some successful dry-lot producers is that corral management and grooming needs as much attention as that given to free-stall management and grooming. Good corral management includes attention to water diversion, routine grooming, corral sloping and drainage, and loafing mounds.
Routine Scraping/Grooming of Corrals – Manure greatly increases the water holding capacity (and softening) of soil; Midwest feedlot managers actually sometimes refer to the top layer of manure and soil as “sponge”. For this reason, light but regular scraping throughout the year is essential. Use of a box scraper or similar implement is preferable to use of a front end loader to prevent gouging the corral surface and disrupting the slope. One trick beef feedlot managers have used to prevent employees from scraping too deeply is to use a screwdriver to measure the depth of the compacted manure and set the scraping implement accordingly.
Water Diversion – In some situations preventing outside surface water from entering the lot may be the simplest, most cost-effective action to reduce mud in a corral. Terraces or trenches can be built to direct water around animal confinement areas and gutters can be used to collect rainfall from building roofs for diversion.
Sloping Corral Surface & Drainage – In order to assure adequate drainage, California has regulations specifying slope for pens ranging from 1 ½ to 3 percent depending on the density of cattle. Beef feedlot experts suggest that more aggressive slopes are needed to provide for adequate drainage with minimum erosion, typically between 3 and 6 percent. Less slope may be needed for pens having a reduced cow density. Ideally the corral surface should be shaped to provide the shortest route for storm water to get to a drainage channel. If possible it’s optimal for each pen to have its own definite drain. Methods used to compact silage in bunkers have been reported to work well for corral surfaces. As described below, fly ash can be used to stabilize both mounds and corral surface.
Loafing Mounds – More than 60% of beef feedlots in the U.S. use mounds and Cooperative Extension literature contains excellent guidance on managing feedlot mounds. In general, mounds should be orientated in the direction of the corral slope to prevent blocking drainage. In some corrals, producers may consider joining the mound to the feed apron and water trough so that cows don’t have to cross muddy areas to access them. Typically, feedlot mounds are recommended to be 5 to 8 feet high with a slope of 4:1 to 5:1 allowing cows to rest comfortably. The mound crown is typically kept only 5 to 10 feet wide; wider crowns tend to promote standing water which softens the surface. Typical recommendations for feedlot mound size are in the 45 square feet per head range. Mound stabilization is critical and fill dirt, preferably clay, should be mechanically compacted during the summer. Methods used to compact silage in bunkers have been reported to work well for mounds.
Fly Ash to Stabilize High Traffic Areas
One method of preventing mud is to use fly ash (or more typically a blend of fly ash and bottom ash) to stabilize the corral surface or lanes of high animal traffic. Fly ash (or flue ash) is a combustion product of industrial incinerators consisting of the fine particles that rise with the flue gases. When collected for use, fly ash has the consistency of talcum powder, making it difficult to transport or apply in its pure form. In contrast, the “bottom ash” which is typically removed from the bottom of the broiler, will have consistency more like fine gravel or course sand. A unique feature of fly ash is its “pozzolanic reaction” with calcium in soil, setting up a mixture that is similar to concrete, greatly stabilizing the surface and minimizing mud. Unlike fly ash however, much of the pozzolanic activity in bottom ash has been lost during its transport in water to storage ponds. Bottom ash then has little benefit as a soil-stabilizing amendment by itself, but it is frequently mixed with fly ash. Such Bottom Ash Blend (BAB) products have soil-like characteristics, are easy to work with and still maintain the ability to bind and stabilize soil. For ease of use, ideally the supplier provides producers with a 70% bottom ash and 30% fly ash mixture, based on volume. If you intend to use fly ash to stabilize high traffic areas, it’s critical that it be sourced from companies using only organic material such as tree trimming and unpainted lumber. Fly ash using other source material (such as tires or treated lumber) potentially contains contaminants which you don’t want on your dairy.
This article is excerpted from “CDQAP Ruminations.” For more information on mud management and other topics related to animal care and improving your bottom line profit, visit CDQAP Ruminations at http://cdrf.org/home/checkoff-investments/cdqap/animal-care-the-cdqap/
Link to PDF Version: Managing Mud on Dairies