Ketosis/Acetonaemia

We always see quite a few cases of ketosis/acetonaemia/sweetbreath at this time of year – so what is it?  It is a metabolic disorder, that results from inadequate nutrient intake (especially energy) by the dairy cow in early lactation. When blood glucose level is too low, the cow mobilizes body reserves, especially fat. Part of the mobilized body fat will be converted to ketones in the liver (e.g. acetone), which results in elevated ketone levels in the blood.  Commonly it occurs ten days to 6 weeks after calving in high producing cows. Peak incidence is about 3 weeks. Many high producing dairy cows go through a sub-clinical primary ketosis in early lactation when milk production exceeds nutrient uptake and body reserve has to be used. Underfeeding, inappetence, fat cows/fatty liver syndrome and butyric silage can all predispose to Ketosis. Other problems such as retained placenta, tyre-wire disease, displaced abomasum can act as predisposing factors to secondary ketosis.

Symptoms;- Loss of appetite especially to concentrates.  A sweet pear-drop smell on the breath and subtly on the milk is discernible by some.  Rumen inactivity appears later but faeces appears firm and “waxy”. There is usually weight loss and lowered milk yield.  There can also be a nervous form sometimes seen with circling, head pressing ,licking walls and abnormal chewing the as main symptoms.

Diagnosis;-  Simple cow-side tests are available to check the ketone levels in the milk and urine as well as a blood test  which measures BHB and  is commonly used in blood profiles as a monitoring tool.

Treatment;-  All treatments of ketosis aim to increase blood glucose level and thus reduce tissue mobilization.

- Intravenous glucose injection: The most rapid and direct way of supplying blood

glucose. However, relapses occur when glucose infusion is used as the sole treatment.

Thus it should be followed by one of the longer acting treatments.

- Hormonal treatment:. Glucocorticoids (cortisone) cause the cow's body to produce

glucose from protein tissues. However, prolonged use of this hormone is not

recommended.

- Oral sugar precursors: Sodium propionate and propylene glycol are two oral sugar

precursors that can be used by the cow to produce sugar in the liver. They can be fed or drenched at a rate of 250-450 g per day usually following glucose or hormonal treatment.

Prevention;-

-         Avoid over-conditioned cows in late lactation and dry period. Overconditioning causes depressed appetite around calving and may increase fatty liver problems. Body condition score should be 2.5-3 at calving. A well managed transition period and fresh cow period and well balanced rations are the key to successful prevention.

-         Monitoring of milk quality results particularly milk proteins via Herd Companion can be an excellent early-warning system.