Fatty liver condition in dairy cattle

SEVERAL METABOLIC disorders that are related to nutrition occur in dairy cows. Most of these occur at or shortly after parturition. They represent a failure of the cow to adjust to the rapid onset and stress of high milk production.

`Fatty liver syndrome' is a poorly defined condition which refers to a combination of metabolic, digestive, infectious and reproductive conditions which affects the obese periparturient cows. The syndrome is more frequently a herd problem

The condition develops mainly due to faulty feed management which permits excessive consumption of unbalanced diets. Cows in early lactation (Between 4 to 8 weeks) will be in negative energy balance, since milk production usually peaks during this period. However, maximum feed consumption usually occurs between 10 and 14 weeks post-parturm. Consequently, cows mobilise fat deposits to overcome the deficit, resulting in weight loss. There will be release of fatty acids and amino acids into the blood. The fatty acids are transported through the blood to various organs such as liver, kidney and muscle and deposited as intracellular triglycerides. The extent of fat deposition depends on the factors like amount of excessive fat, presence of disease and stress complications during calving.

The amount of fat in the liver under normal conditions is quite low (1 to 2per cent). Depending on the conditions it may increase prior to calving, to 4 to 10 per cent (of fresh liver weight). The mobilisation of adipose tissue after calving may result in fat accumulation in the liver, of more than 20per cent. Severely ketotic cows had a greater percentage of fat in the liver than healthy cows. There is a positive relationship between fatty infiltration and blood ketone concentration.

The most useful sign of fatty liver condition is the sight of very fat cows in the dry cow group. Other general signs include depression, loss of appetite, ketone bodies in the urine, marked decrease in milk production, progressive loss in the body condition (debility), weakness, decreased resistance to infection, nervous signs and elevated temperature due to infectious diseases.

Cows which do not respond to treatment die. About one litre of 50 per cent glucose should be administered daily by intravenous route to inhibit fat mobilisation and glucocorticoides. vitamin B12 and cobalt are also used. Calcium, magnesium salts along with glucose provide some improvement. But all treatments are less effective, the longer their commencement is delayed. About 50 grams of choline chloride (50 per cent) is to be given orally once daily. Administration of insulin (Zinc protamine) at 200-300 I.U. by subcutaneous route daily, will promote peripheral use of glucose. Propylene glycol promotes glucose metabolism. Forced excercise haste recovery.

Intake of concentrate feeds should be controlled after peak lactation and conception.

Intake of high energy feed should be limited during dry period. Dairy cows should receive balanced rations in terms of energy, protein and minerals.

About 325 ml of propylene glycol daily as a oral drench or mixed with concentrate and fed separately from forages will be more effective than mixed in the complete rations. Treating the cows with propylene glycol in the last weeks before calving will be most effective.

B. Devasena, M. Parthasarathy

& Z. Prabhakara Rao

Department of Animal Nutrition

College of Veterinary Science

Tirupati

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