Gut health is one of the often underutilized components of a successful operation. Sure, people have a basic understanding of it when it comes to nutrients and their absorption, but that is usually as far as it goes. Producers often need to fully understand what it entails or even what factors can influence it.
When it comes to influencing gut health, there are three main factors. Besides infection, management and environmental factors can control it. Environmental factors can be things like stress from weaning or extreme weather. Management factors will be things like the type of feed that the producer provides to their cattle. Environmental and management factors can cause the infection factor to occur.
Once thought of as just part of the digestive system, research has begun to show the importance of the gut, or the gastrointestinal tract, for the overall well-being of the cow. The gastrointestinal tract is one of a ruminant’s most metabolically active tissues. According to a study in Animals, it accounts for approximately 20% of oxygen consumption and 30% of metabolic processes and protein synthesis. With all the functions the gut does, keeping it in top shape is essential.
What is gut health?
In a simple definition, gut health refers to how well the nutrients from the feed are absorbed. Since the GIT also plays a role in the immunity of the animal, it also means how well pathogens are contained within the digestive tract. When the lining in the gut is weak, microbes and other pathogens can exit the digestive tract and enter the bloodstream. When this happens, the cow is likely to develop an infection or a disease. A strong barrier here is crucial to maintaining good gut health.
Many producers know that maintaining good rumen health is vital for production success. The thing is that there is more to the cattle digestive tract than just the rumen. In order to prevent pathogens from entering, the entire tract needs to be in top shape from beginning to end. Think of it like an engine; if one thing is not running in the right way, it can throw the whole system off balance.
A primary function of the GI tract is to digest and absorb nutrients, defend against harmful pathogens, prevent harmful compounds from entering the body, and maintain a balanced microbiome. The intestinal tract only has one cell layer protecting the body instead of multiple like the rumen. Having only one layer means that the intestinal tract will rely heavily on the immune system to protect it from any pathogens. Depending on the immune system, the tract uses energy that the cow would typically use for production and performance.
A healthy gut:
- Will break down nutrients for optimal absorption
- Promote and maintain a healthy immune system
- Maintain the structural integrity of the intestine
- Preserve the balance of microflora
A damaged GI tract can cause:
- An unbalanced microbiome can cause a higher prevalence of pathogens
- A reduction in digestive and absorptive capacity
- Decreased intestinal integrity of the gut which will allow harmful pathogens and toxins to enter the body
- A compromised immune system
Factors that can negatively affect gut health
Stress in the animal can weaken the animal’s gut. This weakening is what allows pathogens to enter. Some of the more common stressors are things like weaning, transportation, feed restrictions, acidosis, and excessive heat. When these periods occur, it can result in diseases such as laminitis, liver abscesses, acute interstitial pneumonia, and inflammation to happen. Maintaining proper gut health can prevent these diseases from happening, as well as the resulting economic losses they cause.
These stressors affect both the mucosal layer and the intestinal cells’ tight junctions. A breakdown in the tight junctions occurs between the epithelial cell membranes. This breakdown allows for intestinal permeability, which is where the pathogens enter the bloodstream. The pathogens entering the bloodstream will cause an immune response, making cattle more likely to get a disease.
The animal’s diet can also cause problems when it comes to gut health. A diet high in grains will increase the amount of starch that is digested after the rumen. These high-grain diets are the leading risk factor for the animal developing different forms of acidosis. The high amount of starch in the digestive tract causes the pH in the rumen to drop, thus causing acidosis.
Changes in pH caused by acidosis have been theorized to cause more problems in the hindgut rather than the rumen itself. These potential problems are because the single layer of cells in the large intestine might be more vulnerable to an acidic environment than is typically found in the rumen. Since the significant presence of immune cells in the intestine means that any change in the environment there will cause a more extensive inflammatory response.
How to promote gut health
Dietary protein is an essential factor when it comes to maintaining immune homeostasis in the GIT. It is this protein that is digested by microbes in the rumen that keeps them active and increases their numbers. To ensure proper digestion, you need a healthy amount of microbes.
Low-fiber diets can be very stressful for cattle. They are stressful because they allow the fermentation acids to build up in the rumen and cause health problems. The build-up of acids can cause the animal to develop ulcers. The stimulation of good bacteria requires dietary fiber. Despite their benefits, too much fiber can be just a s terrible. Too much fiber can decrease the total tract digestibility because of the increased bulk in the large intestines. I discuss the importance of fiber in the cattle diet in a previous post, “The truth about what roughage does for cattle.”
It is possible to manage internal parasites when grazing animals are present in most situations. The internal parasites that reside in the small intestine can cause the intestinal villi to shrink. What this does is reduce the ability to increase the surface area that is available for absorption. Using the correct type of dewormer at the right time can keep this problem under control.
