Audit finds high levels of hidden ketosis
In a recent audit of UK dairy herds, it was found that the prevalence of subclinical or 'hidden' ketosis averaged 30 per cent in newly calved cows. Levels in individual herds varied from 10 to 60 per cent. These cows were not only found to be more likely to develop clinical ketosis, but were also at greater risk of developing other metabolic and reproductive disorders such as retained placenta, displaced abomasum and milk fever.
763 cows from 15 dairy herds were tested in the UK farm audits. Ketosis was determined by measuring beta-hydroxbutyrate (BHBA) levels in the milk of cows which had calved 7 to 21 days previously. Levels were measured using the cow-side diagnostic Keto-Test, and a positive diagnosis was given when BHBA levels exceeded 100mol/litre. The cows were also observed during the first 35 days of lactation, not only to see if clinical ketosis developed, but also to monitor other potential health problems that may arise.
The study was also conducted across four other European countries - Germany, France, Italy and The Netherlands, testing a total of 2,489 cows. The audit revealed that cows testing positive for hidden ketosis were 11.5 times more likely to progress to clinical ketosis. They were also 1.7 times more likely to have a difficult calving, 2.2 times more likely to have had a retained placenta and 1.8 times more likely to have had milk fever.
Other results suggested these animals were 4.5 times more likely to suffer gastrointestinal distress, 2.3 times more likely to get mastitis and 2.7 times more likely to get a displaced abomasum. The audit additionally found a small but significant trend indicating an increased susceptibility to metritis.
Technical consultant for Elanco Mike Steele said: "Clinical ketosis was diagnosed in 1 per cent of cows surveyed in the main audit. This is in line with previous findings. It highlights that whilst clinical cases of ketosis are rare, these cases are just 'the tip of the iceberg' and a much larger number of animals will be experiencing subclinical levels of ketosis.
"These may develop into clinical ketosis and/or other clinical disease, as the survey demonstrated."
Defra has published guidance for the vet sector ahead of a proposed UK-EU Sanitary and Phytosanitary agreement.
