Corral management can help cut down on mud

Mud matters, and mud also causes many issues on California dairies, including depressed feed intake, reduced feed efficiency, slug feeding and acidosis, and it can contribute to displaced abomasums, lameness and mastitis.

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, according to Michael Payne, director of the California Dairy Quality Assurance Program.

Very little research has been done on the effects of mud on dairy cattle. A study done by the University of California found a negative association between increasing precipitation and milk production, particularly on dairies where cows were housed outside, Payne said.

Cows will be more reluctant to make their way to the feed alley if they have to walk through mud and, depending on the depth of the mud, they can expend significantly more energy, Payne said.

The UC research also found that cows even preferred to lie on concrete rather than in muddy areas.

Increased disease was also found with mud. Cows may eat fewer and larger meals (slug feeding) because they don't want to walk through the mud. This may also increase the incidence of rumen acidosis, laminitis and displaced abomasums, and the lack of cleanliness associated with wet environments has been linked to increases in mastitis and metritis, Payne said. Wet conditions also contribute to softer hooves and increased lameness, he added.

Many if not most mud problems can be managed simply by creating adequate slopes and drainage, and by regular manure removal, Payne said.

The best time to repair, resurface, re-slope and re-compact corrals is during the dry months, Payne said.

"Because manure greatly increases the water-holding capacity and softening of soil, light but regular scraping throughout the year is essential," he said.

Corral management techniques include:

• Diversion of water entering the corral;
• Providing drainage for rainwater;
• Sloping corral surfaces;
• Creation of loafing mounds.

To assure adequate drainage, California has regulations specifying slope for pens ranging from 1.5 percent 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. This is generally between 3 percent and 6 percent.

Less slope may be needed for pens having a reduced cow density. The best design is to have the corral surface shaped to provide the shortest route for stormwater to get to a drainage channel. Optimally, each pen should have its own definite drain, Payne said.

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, Payne said.

"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," he said.

Preventing outside surface water from entering the lot may be the simplest, most cost-effective way to reduce mud in a corral, Payne said.

"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," he said.

Loafing mounds are another option. Over 60 percent of beef feedlots in the U.S. use mounds for cattle to lie on. In general, mounds should be oriented in the direction of the corral slope, to prevent blocking drainage. In some corrals, the mound is joined to the feed apron and water trough, so that cows don't have to cross muddy areas to access them, Payne said.

Typically, loafing mounds are recommended to be five to eight feet high with a slope of 4-to-1 to 5-to-1 that allows cows to rest comfortably, he said. The mound crown is generally kept only five to 10 feet wide. Wider crowns may promote standing water, which would soften the surface.

Mound stabilization is critical and fill dirt is preferably clay. It should be mechanically compacted during the summer. Methods used to compact silage in bunkers have been reported to work well for mounds, Payne said.

Mounds aren't the only way to minimize mud inside pens, Payne said. For many dairies, soil stabilization with wood chips, gravel, road base or fly ash may only be required in high-traffic lanes, feed alleys and watering troughs.

Incorporation of fly ash into the corral can significantly help to stabilize soil and minimize mud. It's important to get fly ash from incinerators that only use organic material like coal, prunings or untreated, non-painted lumber to avoid contaminants like heavy metals, Payne said.

Fly ash, or more typically a blend of fly ash and bottom ash, can be used to stabilize the corral surface or lanes where there is high animal traffic.

"A unique feature of fly ash is its pozzolanic reaction with calcium in soil, setting up a mixture that is similar to concrete," Payne said, adding this greatly stabilizes the surface and minimizes mud.

Just spreading fly ash on a corral surface won't be effective. When applying fly ash, water and compaction are critical if significant strength is to be achieved, he said. Fly ash, or a fly and bottom ash blend mixed with the soil at a 50/50 ratio, watered and mechanically compacted, is the most effective.

This can be done with a front-end loader or a PTO-powered tiller, but the mixing has been reported to be difficult and time consuming, Payne said. Watering and compacting a fly ash / bottom ash blend to create a pad on top of existing compacted soil is reported to be a significantly more efficient installation, but requires more ash.

Using proper construction techniques and good corral management, pens stabilized with combustion products can potentially last many years.

"Corrals stabilized with coal ash at the Texas A&M research feedlot in Bushland, Texas, were created 25 years ago and are still holding up well," Payne said.

For more information on the economics of mud management and other animal care topics, go to http://cdrf.org/home/checkoff-investments/cdqap/ animal-care-the-cdqap/. The California Dairy Quality Assurance Program is supported by the California Dairy Research Foundation.

(Kathy Coatney is a reporter in Bend, Ore. She may be contacted at kacoatney@gmail.com.)