Fatty Liver Syndrome (FLS) in Cattle

Fatty Liver Syndrome (FLS) is a common metabolic disorder in dairy cows, especially during the transition period around calving. It occurs due to the excessive accumulation of fat in the liver, which impairs its ability to perform vital functions such as detoxification, energy regulation, and nutrient metabolism. This condition leads to reduced milk production, fertility problems, and increased susceptibility to other diseases.

What is Fatty Liver Syndrome?

In normal cows, the liver contains small amounts of fat. In FLS, however, excessive fat is deposited, leading to impaired function. This condition typically arises during the periparturient period when cows face Negative Energy Balance (NEB) due to high energy demand for milk production combined with reduced feed intake. Mobilized body fat gets deposited in the liver, causing fatty infiltration and dysfunction.

Causes of Fatty Liver Syndrome

The condition develops due to a combination of nutritional, metabolic, and management factors. Key causes include:

1. Negative Energy Balance (NEB): Reduced feed intake post-calving and increased energy demand for lactation cause mobilization of body fat, which is then deposited in the liver.
2. Inadequate Nutrition: High-grain, low-fiber rations lead to rumen disturbances and inadequate nutrient supply, while deficiencies of protein, vitamins, and minerals impair fat metabolism.
3. Obesity / High Body Condition Score (BCS): Over-conditioned cows mobilize fat more rapidly, predisposing them to fatty liver.
4. Hormonal and Stress Factors: Increased cortisol, insulin resistance, and calving stress reduce feed intake and enhance fat mobilization.
5. Genetic Susceptibility: High-yielding dairy breeds are more prone to FLS compared to indigenous breeds.

Clinical Signs of Fatty Liver Syndrome

The severity of symptoms depends on the extent of liver fat infiltration. Common signs include:

1. Reduced Feed Intake: Cows show poor appetite or anorexia.
2. Weight Loss: Despite fat accumulation in the liver, cows lose body weight rapidly.
3. Decreased Milk Yield: Significant drop in milk production soon after calving.
4. Weakness and Lethargy: Cows appear dull and less active.
5. Jaundice (Severe Cases): Yellow discoloration of mucous membranes.
6. Secondary Diseases: Increased risk of ketosis, displaced abomasum, and uterine infections.

Diagnosis of Fatty Liver Syndrome

Diagnosis involves history, clinical findings, and confirmatory tests:

1. History and Clinical Examination: Reduced appetite, milk yield, and rapid weight loss post-calving.
2. Blood Tests: Elevated liver enzymes (AST, GGT, ALT), high ketones, and low glucose levels.
3. Ultrasound: Fat infiltration visible in the liver.
4. Liver Biopsy: Definitive test to confirm fat deposition in hepatocytes.

Treatment and Management

Management requires correcting energy deficits, supporting liver function, and treating complications:

1. Correcting Energy Deficit: Provide high-energy, palatable diets including silage, concentrates, and rumen-protected fats.
2. IV Therapy: Glucose infusion to increase blood sugar; lipid emulsions to provide energy.
3. Drug Support: Corticosteroids to stimulate glucose metabolism; Vitamin E and Selenium for liver protection.
4. Supportive Care: Ensure hydration, reduce stress, and treat concurrent conditions like ketosis or metritis.

Prevention of Fatty Liver Syndrome

Prevention is more effective than treatment. Key measures include:

1. Maintain Optimum BCS (2.5–3.5) before calving to avoid over-conditioning.
2. Gradual Diet Transition: Smoothly move cows from dry period to lactation diet.
3. Energy-Dense Pre-Calving Diet with high fiber content.
4. Close Monitoring: Regularly track appetite, BCS, and milk yield during the transition period.

Conclusion

Fatty Liver Syndrome is a major metabolic disease in dairy cows that leads to significant losses in productivity, fertility, and herd health. Early detection, balanced nutrition, and preventive management during the transition period are crucial to minimizing its impact and ensuring better herd performance.