Tackling liver abscesses in the beef-on-dairy industry
What are the challenges, impacts and solutions?
By Ty Lawrence and Olivia Genther-Schroeder
Liver abscesses are primarily a concern in the fed-beef sector with an exceptionally high prevalence in beef-on-dairy animals. Due to their high incidence and severity in dairy-reared cattle, these abscesses are a significant problem, prompting extensive industry-wide research and discussion. A recent beef-on-dairy conference hosted by Purina Animal Nutrition highlighted the urgency of addressing this issue. The industry's recognition of liver abscesses as a significant problem underscores the need for practical solutions to improve animal welfare and economic viability.
The challenge with liver abscessesCattle afflicted with liver abscesses, or pus-filled capsules within the liver caused by bacterial infections, often exhibit reduced feed intake, slower weight gain and compromised overall health, which diminishes their productivity. Liver abscesses often present as raised capsules or lumps that vary in size from a few millimeters to several centimeters in diameter. These capsules are typically yellow, green or white, notably contrasting against the normal reddish-brown hue of healthy liver tissue. The surface of the liver around the abscessed areas often appears swollen and inflamed.
Liver abscesses are graded based on their severity, and this grading is directly associated with the health and productivity of the animals:
Minor abscesses (A- and A): Generally, do not significantly affect animal performance. At harvest, these livers present with small abscesses and healing scars from resolving abscesses. USDA inspectors assess these scars to determine whether the liver is edible. If the scar is completely resolved, the liver may pass inspection. Otherwise, it may be condemned.
Severe abscesses (A+, A+ adhesion, A+ open and A+ adhesion/open): Significantly impact animal health, reducing dry matter intake, weight gain and feed conversion efficiency. Severe abscesses can render large areas of the liver non-functional with some animals relying on only a portion of their liver, drastically reducing metabolic health and productivity. Severe liver abscesses can also cause adhesions, where the liver adheres to other body components, such as the diaphragm and lungs. These adhesions reduce beef value by eliminating the opportunity to market skirt steak. They may also complicate breathing, potentially presenting as Bovine Respiratory Disease (BRD), and may lead to other challenges including antibiotic therapy. Open abscesses lead to the condemnation of the entire gut mass, converting valuable edible products into low-value meat and bone meal.
Economic impact for producers and packersFrom an economic standpoint, liver abscesses cause substantial financial losses for cattle producers and beef processors. For cattle producers, the condition leads to reduced efficiency in converting feed to muscle, resulting in lower market weights and diminished returns on investment. For beef processors, liver abscesses lead to the condemnation of affected livers and skirt steak, translating to direct financial losses. Condemning portions of the carcass and offal impacts overall profitability, as the industry must adhere to stringent food safety regulations that mandate the removal of contaminated tissues.
Abscesses can have severe implications beyond just the liver, as the infection can spread to and negatively impact the viscera or nearby organs in the body cavity. This contamination can result in the loss of valuable meat cuts such as the skirt steak, which is derived from the diaphragm of the animal. The skirt steak is one of the most significant losses in severe liver abscesses. This particular cut of meat is highly valued because it is commonly used to make fajitas, a popular dish in many cuisines.
Liver abscesses contribute to an estimated $900 million in annual losses, excluding downtime and downgraded product implications.1 The approximate beef processor financial losses due to liver abscesses varies significantly depending on the severity of the condition.
A and A- abscesses: $5.1 million loss, primarily due to a $4 loss per liver.
A+ abscesses: $18 million loss with $55 lost per occurrence, including $4 from the liver and $51 from reduced hot carcass weight.
A+ abscesses with adhesions: $60 million loss, averaging $150 per case, due to the combined losses of the liver, hot carcass weight and skirt steak.
A+ open abscesses: $23 million loss with each occurrence costing $147, factoring in losses from viscera and hot carcass weight.
A+ open abscesses with adhesion: The most severe case with $167 million in losses, or $239 per instance, impacting viscera, hot carcass weight and skirt steak.
These losses show the need for effective management and nutrition strategies to mitigate liver abscesses.
Proper nutrition as a first line of defenseImplementing effective nutrition strategies can help reduce the incidence of liver abscesses in cattle. Health of the gastrointestinal tract is the most critical factor influencing development of liver abscesses, and poor gut health can allow the causative bacteria to move from the environment and gut contents to the liver, increasing the risk of liver abscess formation. To maintain a healthy gut, cattle should be provided a diet with sufficient physically effective fiber content to promote healthy rumen function and minimize acidosis, a primary risk factor for liver abscesses. It is important to avoid feeding cattle excessive amounts of highly fermentable carbohydrates, which can excessively lower the rumen's pH and lead to digestive issues.
Ensuring a healthy gut starts on day one of a calf’s life. The physical structure, immune tissue and microbiome of the gut are all being established in the first few weeks and months of a calf’s life. Therefore, is it key to support this development with nutrition and management.
Colostrum provides essential antibodies and nutrients critical for the calf’s early development. To optimize the benefits to the calf’s immune system and overall health, colostrum needs to be fed shortly after birth and at an adequate volume. The ideal colostrum feeding program will vary across farms as it is dependent on both available colostrum quantity and quality (IgG concentration). Splitting colostrum into two feedings within the first 12 hours of life may allow for greater IgG concentration without stressing the capacity of the calf’s stomach.
According to Purina research, producers should avoid feeding low planes of nutrition, and beef-on-dairy calves should be fed at least 1.5-1.8 pounds of milk replacer daily along with a starter feed containing 20% protein.2 Producers should also avoid early weaning and adhere to the standard of at least eight to nine weeks as with purebred Holstein calves.
Feeding greater planes of milk nutrition and weaning later allows calves to more gradually adapt to solid feed, which can reduce the risk of ruminal and hindgut acidosis. Providing more milk nutrition also allows for greater growth rates and can result in lower cost per lb. of gain. Feeding calves age-appropriate diets that optimize health and growth is important for supporting long-term gut health.
References1 West Texas A&M University. 2024. “WT Scientists Taking Part in Research into Costly Cattle Liver Abscesses.”
2 Data in this article is from research trials conducted at the Purina Animal Nutrition Center: Studies CT-02-20, CT-09-20, CT-13-20, CT-02-21, CT-04-21, CT-08-21 CT-11-21, CT-16-21.
Lawrence is a professor of animal science and director of Beef Carcass Research Center at West Texas A&M University and Genther-Schroeder is a technical innovation manager, CMR & Dairy for Purina Animal Nutrition.
