Evaluation of a milk test for detection of subclinical ketosis.
This study included 190 lactating cows from eight dairy farms and was designed to investigate the sensitivity and specificity of a milk test (Ketolac) for detecting subclinical ketosis in dairy cattle. Blood and milk samples were collected between 38 and 50 days post partum. At a beta-hydroxybutyric acid concentration in blood of 1.2 mmol/L, the prevalence of ketosis was 14%. A Response Operator Characteristic curve was drawn for two milk test values: 100 mumol/L and 200 mumol/L. Assessment of several beta-hydroxybutyric acid cut-off values in blood showed that when 100 mumol/L on the Ketolac milk test was defined positive, the most desirable sensitivity-specificity combination was achieved. This milk test can be routinely used to screen a herd for subclinical ketosis.
Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
R
R
Jorritsma
S J
SJ
Baldée
Y H
YH
Schukken
T
T
Wensing
G H
GH
Wentink
D000818:Animals; D002417:Cattle; D005260:Female; D007662:Ketosis / Q000175:diagnosis / Q000662:veterinary*; D008892:Milk / Q000737:chemistry*; D015995:Prevalence; D012680:Sensitivity and Specificity