Rumen acidosis is a metabolic disease that can show clinical signs or affect your cows sub-clinically. Cattle experience rumen acidosis when their rumen pH levels drop below 5.5 (normal pH levels range from 6.5 to 7.0). Imagine eating something overly acidic and feeling nauseated. It’s like that for cows, only worse. The effect on cattle can range from reduced milk production to death, depending on the severity of rumen acidosis.
To avoid reduced milk yields and health issues in your dairy herd, rumen acidosis prevention and treatment can be your best tools. Read on to understand the different types of rumen acidosis, causes, symptoms to watch for, and how to treat and prevent this condition.
Acute vs. Subacute Ruminal Acidosis (SARA)
The main difference between acute vs. subacute ruminal acidosis (SARA) is that the acute form manifests after a more severe pH drop, causing a strong acidic environment in the rumen.
- Acute ruminal acidosis is often fatal and has more apparent symptoms. It’s more associated with feedlot cattle than dairy cows. The pH reduction is often abrupt.
- Subacute ruminal acidosis, or SARA, is a milder type of acidosis where the rumen repeatedly goes into the 5.2-5.6 range for several hours daily, and it’s highly common in dairy cattle. According to Ohio State University, up to 33% of dairy cattle experience SARA during lactation.
SARA is insidious. It’s prevalent, often quiet, and can reduce your profits while your cattle suffer in silence. When farmers talk about preventing or treating ruminal acidosis, the focus is primarily on SARA.
What Causes Rumen Acidosis
The primary cause of rumen acidosis is high amounts of rapidly digestible carbs without sufficient effective fiber.
Under normal conditions, cows maintain a healthy ruminal pH level with saliva and volatile fatty acids (VFAs) absorption in the rumen. The fiber content stimulates saliva production, while the rumen’s microbes ferment feed to produce VFAs, which are absorbed for energy. It all goes well, unless the system is overloaded with carbs.
Starches and grain sugars cause rapid fermentation and a massive surge of VFAs. The rumen’s response? Excessive pH drops into the acidic range. In SARA, the effect isn’t as pronounced. The pH dip may last several hours before it recovers as the cow starts ruminating, making pH swings hard to spot while still reducing productivity.
Acute rumen acidosis occurs when cattle consume excessive amounts of starch or sugar, triggering a rapid overgrowth of lactic acid-producing bacteria in the rumen. These bacteria thrive in an acidic environment and produce lactic acid, which is significantly stronger than VFAs. This sets off a downward spiral of pH and lactic acidosis.
Milk Fever & Rumen Acidosis
Milk fever is an entirely different metabolic disease from rumen acidosis. However, they often interact during the transition period around calving. Since milk fever occurs due to a sudden drop in calcium when milk production begins, its effects can intertwine with rumen acidosis.
Low blood calcium can prevent muscle contraction, including rumen and intestinal muscles. As a result, the cow will reduce her intake. What follows can be very dangerous. When calcium levels correct, cows may overeat to compensate, triggering acidosis due to a previous rumen slowdown. Like other common cow illnesses, you can manage milk fever with adequate feed formulation through your independent nutritionist.
Acidosis Consequences
The acidic environment can damage the rumen lining and cause ulcers or rumen erosion, organ and blood issues, rumen bacteria entering the bloodstream, and other health concerns.
The health impact may be minimal in less severe cases and develop over time. However, SARA has long-term effects, such as reduced feed intake, lowered milk fat content, and reduced milk yield. Ultimately, SARA is a significant economic factor that drives down your farm’s profits.
Signs of Acidosis in Dairy Cows
For acute acidosis, symptoms are often obvious: complete loss of appetite, diarrhea, depression, dehydration, elevated heart rate, and death.
However, signs of SARA can be trickier to spot. Pay attention to these subtle signs of reduced health and performance:
- Inconsistent or reduced feed intake, especially if the cow is eager to eat at first and then loses appetite later in the day
- Foamy and loose manure
- Lowered milk production, especially combined with reduced fat content
- Gradual weight loss
- Less time spent ruminating
- Mild fever
- Elevated heart rate
- More frequent hoof issues and lameness
- Displaced abomasum
- Lethargy
- Liver abscesses
- Ruminitis
How to Prevent Acidosis in Cattle
While it’s challenging to fully prevent any SARA from occurring, you can manage it to reduce its impact with quality feed formulation and diet.
By using high amounts of grain in the diet to maximize cow gains and productivity, farmers are exposing their cattle to rumen acidosis. However, you don’t need to compromise productivity to manage acidosis. It’s possible to get the best of both worlds and keep a reasonable pH that won’t cause excessive health issues or yield loss.
- Reduce fermentable carbohydrates consumed at feedings.
- Don’t ignore fiber. Use long forage fibers to enhance the cow’s buffering ability. Forage NDF should be between 17% and 23%.
- Use an adequate feed formulation, possibly including dietary buffers (e.g., potassium carbonate or sodium bicarbonate).
- Supplement diet with microbials to improve lactate utilizers in the rumen.
- Use cow feed with an appropriate particle size distribution to prevent selective feeding behavior by cattle. This helps promote a more stable rumen pH.
- Ensure enough lying space for cows to stimulate rest time and rumination.
- Use effective feed bunk management. If cows feel competition for the bunk area, they’ll overconsume and increase rumen pH. Likewise, they’ll overcompensate during the next feeding if they missed a meal due to insufficient feed bunk space.
Animal nutrition quality is more than half the battle with SARA. Its effect can’t be overstated. Formulating the right blend of grains, fiber, and supplements for your herd’s condition, stage, and productivity goals makes all the difference.
Star Blends produces quality dairy cow feed under guidance from your nutritionists’ ingredient recommendations. Our custom feed blends can help your cows be at their most productive, while staying healthy and thriving, during all life stages.
Cow Acidosis Treatment
SARA is usually prevented or treated with a management plan as described above. However, acute cow acidosis requires actual treatment. Still, the chances of success will depend on the severity of the symptoms.
Immediately contact a veterinarian if you suspect acute rumen acidosis. Almost all acute cases require quick treatment. Cows should be medicated with acid-neutralising and anti-inflammatory drugs as soon as possible. The most radical approach is rumen washing, followed by neutralizing the rumen pH and fluid therapy as a vet recommends. They can do this procedure via surgery or using a large-diameter stomach tube.
Star Blends: Your Partner For Productive Custom Cow Feed
Rumen acidosis can be a silent profit killer, affecting milk production, herd health, and overall efficiency. Preventing acidosis starts with the right balance of nutrients and a well-managed diet.
Star Blends can help you avoid the effects of SARA and acute acidosis by working with your nutritionist to create custom feed blends that support rumen health, promote proper digestion, and help prevent metabolic disorders. Keep your cows performing at their best with high-quality, scientifically formulated feed. Talk to Star Blends today to optimize your herd’s nutrition!
