Causes & Control of Bovine Ketosis (mainly in dairy herds)

Phil Rogers MRCVS <philrogers@eircom.net>
Grange Research Centre, Dunsany, Co. Meath, Ireland
21-Mar-2001

Herd ketosis | Causes (Primary, Secondary) | Remedies

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 Inadequate energy intake; inadequate forage feeding space, feeding from compacted self-feed silage, inadequate concentrate inputs
2 Poor quality silage High pH, >4.3 for unwilted silages; low DMD, <65%; high butyric acid, >0.5% DM; high ammonia-N, >10% of total N
3 Disturbed rumen function (antibiotic contamination of dairy ration; severe Co deficiency) 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.
4 High protein feeds 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!
5 Disturbed overall metabolism Some authors noted increased prevalence of ketosis in herds deficient in I.

Common causes of SECONDARY KETOSIS include:

1 Inappetance Intercurrent disease; lameness; lesions in the mouth, teeth, gums etc
2 Sequel to periparturient problems Dystocia; retained placenta; milk-fever; thin-cow syndrome; fat-cow syndrome
3 Foreign body reticulitis Seldom a herd problem
4 Others 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:

  Remedial actions Comments
1 Identify and correct the causes Identify and correct the main causes, as summarised above.
2 Improve forage utilisation 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).
3 Mineral supplements? 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.

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