Ketosis (also known as acetonaemia) is a common metabolic condition seen in high yielding dairy cows typically during early lactation. It is characterised by high circulating levels of non-esterified fatty acids (NEFAs) in the blood, together with their metabolic products, ketones (acetone, acetoacetate and beta-hydroxybutyrate which is also known as BHB).
In its extreme form, when ketones accumulate to very high levels we can see cows exhibiting a range of strange behaviours. This includes head-pressing, twitching, licking excessively and being generally uncharacteristically nervous of her surroundings. We typically refer to this condition as nervous ketosis. Whilst these cases are often the ones that stick in our minds, they tend to be in the minority. The less extreme form is more common where the accumulation of ketones in high yielding cows results in reduced feed intakes, milk drop and lethargy.
High yielding cows are at most risk of becoming ketotic due to the high energy demand required to produce milk. When intakes cannot support this demand often around peak yield, the cow slips into an energy deficit. This is often referred to as negative energy balance. This is a fairly simple direct relationship and so is termed ‘type 1’ or ‘primary’ ketosis. When diet formulation and feed intakes are both adequate type 1 ketosis will be well managed.
The second high risk time point during the production cycle of a cow is immediately after calving. This is slightly different to the type 1 ketosis. This is because it occurs secondary to another event and so it is termed ‘type 2’ or ‘secondary’ ketosis. We often refer to this as poor transitioning.
The drivers for development of type 2 ketosis include:
- excessive body condition at calving
- reduced intakes associated with post-partum conditions such milk fever and metritis
- or indeed conditions not associated with calving such as lameness and mastitis.
Unfortunately, unless we can break this cycle of ketosis leading to inappetence which leads to further ketone production, more serious events such as displaced abomasums often follow.
This winter, when many clamps may not be as full as we’d like, diets could well be sub-optimal or at best variable. As a consequence, it’s likely that we will experience more ketosis across the dairy herds that we service. However by being proactive you can better manage the risk of ketosis in your herd. Firstly, routine screening using either blood or milk sampling at key stages around calving and peak lactation makes an excellent start to determine the extent and nature of any ketosis. Depending on the results, we can help optimise transition. Please speak to us to find out how we can help.
Identifying high risk cows for Ketosis
There are three simple selection criteria for identifying cows at high risk of Ketosis on farm:
Over condition cows
- Cows with BCS greater than 3.5 but also thin cows with a BCS less than 2
- Heifers older than 27 months at calving
- Any animals carrying twins
Third lactation or more
Cows are more likely to develop Ketosis from the 3rd lactation, when their production in relatively high.
Poor transition during previous calving
Those who have developed a transition disorder in the first month after calving are more at risk. (Ketosis, displaced abomasum, metritis, mastitis, retained placenta, impaired fertility…)
Our VetTechs are trained to carry out our Transition Check service. This involves scoring all dry cows for condition and rumen fill to identify problem cows and housing monitoring to manage environmental issues.
Cows are followed through post calving to monitor BHB results for evidence of subclinical ketosis.
A very useful offering from our VetTech team is their Kexxtone application service. They are able to come on to farm and identify the cows most at risk of Ketosis as prescribed by your vet. Utilising this information they will insert the boluses at the optimum time of three weeks before calving.
Please ask us for more information about how our VetTechs can help.