Causes & Control of Bovine Ketosis

HERD KETOSIS is most common in high-yielding dairy herds. It arises when energy absorption can not match energy demands for milk yield. Fat is mobilised and ketone synthesis increases. Ketosis may be primary or secondary.

Common causes of PRIMARY KETOSIS include:

1. Undernutrition / feed restriction relative to high yields


2. Poor quality silage


3. Disturbed rumen function (antibiotic contamination of dairy ration; severe Co deficiency)






4. High protein feeds





5. Disturbed overall metabolism

Inadequate energy intake; inadequate forage feeding space, feeding from compacted self-feed silage, inadequate concentrate inputs

High pH, >4.3 for unwilted silages; low DMD, <65%; high butyric acid, >0.5% DM; high ammonia-N, >10% of total N

Antibiotic contamination of dairy ration can arise if feeds (containing permitted antibiotics) for pigs, poultry or other animals cross-contaminate dairy feeds. Oral antibiotics (especially Lincomycin) can destroy ruminal microorganisms, thus causing digestive upsets and ketosis.

Rumen microbes need Co for their synthesis of B vitamins and also for optimal digestion of cellulose and carbohydrate.

These may increase the risk of herd ketosis. However, high protein feeds are rarely fed at high levels in Ireland. The exception is grazed grass, which has a mean of 3.5 (range 2.5-5.5)% N, or 21.9 (range 15.6-34.4)% CP, in DM. Primary ketosis is rare at grass, unless the animals are starving!

Some authors noted increased prevalence of ketosis in herds deficient in I.

Common causes of SECONDARY KETOSIS include:

1. Inappetance


2. Sequel to periparturient problems

3. Foreign body reticulitis

4. Others

Intercurrent disease; lameness; lesions in the mouth, teeth, gums etc

Dystocia; retained placenta; milk-fever; thin-cow syndrome; fat-cow syndrome

Seldom a herd problem

Fatty liver, calving problems, lowered immunity, infertility, cystic ovary, NDO, lameness and mastitis may be associated with ketosis.

REMEDIAL ACTIONS to correct herd problems of ketosis include:

1. Identify and correct the causes

2. Improve forage utilisation








3. Mineral supplements?

Identify and correct the main causes, as summarised above.

Where the problem is due to poor quality silage (see above), feeding a better silage, or inclusion of Monensin (250-300 mg/cow/d) in the dairy ration may help. Monensin is not licensed for use in dairy cows in the EU, but can normalise urine and blood ketones in a few days. At 300 mg/cow/d, it decreased milk fat level by 0.19% but was not detected by standard milk residue tests. With very sophisticated methods, levels of 2.5 ng/ml may be detected (Lowe et al 1991 Australian Vet. J., 68,17).

Apart from Co deficiency, mineral deficiency seldom causes ketosis. However, if the levels of Co, Cu, Se, I, Mg or P are low on blood test, it is advisable to increase the input of those elements. A quick way to check if mineral deficiency is involved is to give a high-P lactation mineral, high in Co and other trace-elements.

If the problem persists after 3 weeks, mineral deficiency is unlikely to be a cause. Note that if minerals are only marginally deficient in blood, further supplementation with those minerals is unlikely to improve milk yield.

Phil Rogers MRCVS, Lucan, Dublin, Ireland​
Fax: 353-46-26154 Tel: 353-46-26740 (Lab)
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