dc.description.abstract
Subclinical ketosis (SCK) is defined as concentrations of β-hydroxybutyrate
(BHBA) ≥ 1.2 to 1.4 mmol/L and it is considered a gateway condition for other
metabolic and infectious disorders such as metritis, mastitis, clinical
ketosis, and displaced abomasum. Reported prevalence rates range from 6.9 to
43% in the first 2 mo of lactation. However, there is a dearth of information
on prevalence rates considering the diversity of European dairy farms. The
objectives of this study were to (1) determine prevalence of SCK, (2) identify
thresholds of BHBA, and (3) study their relationships with postpartum
metritis, clinical ketosis, displaced abomasum, lameness, and mastitis in
European dairy farms. From May to October 2011, a convenience sample of 528
dairy herds from Croatia, Germany, Hungary, Italy, Poland, Portugal, Serbia,
Slovenia, Spain, and Turkey was studied. β-Hydroxybutyrate levels were
measured in 5,884 cows with a handheld meter within 2 to 15 d in milk (DIM).
On average, 11 cows were enrolled per farm and relevant information (e.g.,
DIM, postpartum diseases, herd size) was recorded. Using receiver operator
characteristic curve analyses, blood BHBA thresholds were determined for the
occurrence of metritis, mastitis, clinical ketosis, displaced abomasum, and
lameness. Multivariate binary logistic regression models were built for each
disease, considering cow as the experimental unit and herd as a random effect.
Overall prevalence of SCK (i.e., blood BHBA ≥ 1.2 mmol/L) within 10 countries
was 21.8%, ranging from 11.2 to 36.6%. Cows with SCK had 1.5, 9.5, and 5.0
times greater odds of developing metritis, clinical ketosis, and displaced
abomasum, respectively. Multivariate binary logistic regression models
demonstrated that cows with blood BHBA levels of ≥ 1.4, ≥ 1.1 and ≥ 1.7 mmol/L
during 2 to 15 DIM had 1.7, 10.5, and 6.9 times greater odds of developing
metritis, clinical ketosis, and displaced abomasum, respectively, compared
with cows with lower BHBA blood levels. Interestingly, a postpartum blood BHBA
threshold ≥ 1.1 mmol/L increased the odds for lameness in dairy cows 1.8 (95%
confidence interval: 1.3 to 2.5) times. Overall, prevalence of SCK was high
between 2 to 15 DIM and SCK increased the odds of metritis, clinical ketosis,
lameness, and displaced abomasum in European dairy herds.
de
