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Animal Health

Soil microbes, rumen components require specific environmental considerations

The microflora of the cattle’s digestive tract requires balance and a healthy environment, and Montana State University Extension Educator Elin Westover says that soil microbiota needs many of the same components.

“To be profitable and sustainable, producers must realize that the soil, like the rumen, is a biological system and must be managed accordingly,” she notes. 

Every component

Westover comments that every component of the cattle’s gut is important.

“Just as microbial activity is important, dead ‘bugs’ have an essential role in the biological system, too,” she says. “As the microorganism population in the rumen dies, they are passed to the lower gastrointestinal tract where they are degraded and utilized as a protein source by the host animal.”

The microbes in the rumen can provide between 20 and 60 percent crude protein on a dry matter basis, with bacteria providing up to 50 percent crude protein. 

Microorganisms in the soil are also broken down and utilized by plants.

“This nutrient cycling is an important facet of soil health and plant nutrition,” Westover adds.

Balance

Achieving balance in the diet of cattle is also important, and too much of expensive supplements can result in waste.

“If ranchers feed cattle more protein than needed, the protein is used as an expensive energy source, rather than a nitrogen source,” Westover says. “Additionally, there is a point that it starts to cost the animal energy to get rid of excess nitrogen.”

Excess protein may also result in infertility because of high pH levels in the uterus. 

“If we add more nitrogen fertilizer to the soil than is needed, it will not be efficiently utilized and is often lost through leaching beyond the reach of the plant roots or as a gas to the atmosphere,” Westover adds.

Sensitive environment

In looking at the environment in both the rumen and the soil, Westover emphasizes that moisture and temperature levels are important to consider, as they impact microbial activity.

“Consequently, it is critical to understand and manage the environment of the rumen and the soil,” she explains.

In an anaerobic, or oxygen-free environment, the cattle rumen works as an effective fermentation vat, maintaining a constant temperature, pH and moisture content. 

“It is important to note the environment can change as a result of diet, such as a grain versus roughage diet, but as long as it is changed over a period of time, the microorganisms can adapt,” Westover notes. 

In the soil, Westover says microbes function best in moist, warm conditions.

“Soil can be thought of as a semi-aquatic environment,” she explains. “Each species of microorganism functions best at a specific temperature and pH.”

Temperature regulation can be achieved through use of cover crop residue, and fertilizers can help to maintain a neutral pH in the soil.

“It is always a good idea to test soil before spending lots of money to amend it or potentially harm it,” Westover comments. “Furthermore, increasing the diversity of the organisms in the soil will provide balance and stability to soil pH in the rhizosphere – the area immediately surrounding plant roots where soil organisms are concentrated.”

Biology

The biology of both the rumen and plant roots also operate similarly.

Papillae line the cattle’s rumen, and villi cover the surface of the small intestine, and both function to absorb nutrients and water.

“The size and amount of villi and papillae change as the diet changes,” Westover notes. “The function of the papillae and villi is to increase the surface area, and therefore increase the absorption of nutrients and water.”

Likewise, root hairs, or extensions of the root, serve as the uptake mechanism for nutrient and water uptake in plants.

“Plants associated with mycorrhizal fungi can also increase the volume of the soil that can be accessed by plants,” she explains. “Fungal hyphae are like a second set of roots that explore the soil for water and nutrients.”

Water and nutrients require healthy papillae and villi in cattle and root hair and fungal hyphae in plant and soil systems. 

Diversity

“All microorganisms have a specific role and utilize specific organic matter,” Westover says. 

In the rumen, diversity allows better for performance and more effective nutrient extraction. 

“Ruminant animals perform better when on a diverse, non-monoculture diet that provides the microorganisms and animal with a complete diet of nutrients, including vitamins and minerals,” she adds. 

At the same time, diverse crops and rotations are also beneficial.

“One of the benefits of crop rotations and diversified planting is an array of root structures to scavenge nutrients and water from different levels in the soil and make them available,” says Westover. “Increasing plant diversity increases soil health and soil function by providing the soil food web with nutrients, energy and water cycling.”

Consistency

Overall, when the environment of the rumen and the soil are functioning properly, Westover says productivity is increased, but consistency and continual attention is important.

“Cattle and sheep need access to a continual and consistent food supply to perform to their genetic potential,” she adds. “Furthermore, the rumen microorganisms are unable to function to their potential when their feed source is inconsistent.”
At the same time, soil biology has a preferred “food” source that allows plants to thrive.

“Plants do not thrive in soils that are low in organic matter because microorganisms have limited access to feed,” Westover notes. “Both rumen microorganisms and soil microorganisms suffer from intermittent feed availability.”

Maintaining the bacteria, protozoa and fungi in both the soil and cattle rumen is important, and the two can be managed utilizing the same principles. 

This is the second article in a two-part series. The first part, titled “Westover: Soil health management mimics management of cattle rumen,” appeared in the March 8, 2014 edition of the Roundup.

Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at saige@wylr.net.