Incidence of subclinical ketosis in cows supplemented with a monensin controlled-release capsule in Holstein cattle, Florida, USA.
The objective of this study was to determine the effect of a monensin controlled-release capsule on the proportion of cows with subclinical ketosis (SK). During July to August 2001, 300 cows dried-off 50-70 days before expected parturition were randomly assigned to either a treatment (n = 150, oral capsule, 335 mg/d of monesin for 95 d) or control group (no capsule, n = 150). At 14 days postpartum, a milk sample was obtained and evaluated for beta-hydroxybutyrate (BHBA) using a semi-quantitative ketone test strip. In a sub-sample of 50 cows per group a blood sample was taken and analyzed for BHBA using an ELISA kit. Milk BHBA > or = 200 micromol/L was used as the cut-off value for diagnosis of SK. The incidence of SK based on the milk test was statistically different between groups (P < or = 0.05) with a value of 26.6% for control and 14.5% for cows treated with monensin, respectively. Cows treated with monensin were 0.68 times less likely to give a positive result for milk BHBA than non-treated cows (0.53-0.80; 95% CI). Serum BHBA concentrations did not differ between groups (0.81 +/- 0.09 mmol/L versus 0.70 +/- 0.07 mmol/L for controls and treated, respectively; P > 0.05). However, for each incremental increase in serum BHBA of 0.1 mmol/L occurrence of SK increased 52% (OR = 1.52; 1.21-1.91; 95% CI).
Melendez
P
P
College of Veterinary Medicine, University of Florida, P.O. Box 100136, Gainesville, FL 32610, USA.
Goff
J P
JP
Risco
C A
CA
Archbald
L F
LF
Littell
R
R
Donovan
G A
GA
D020155:3-Hydroxybutyric Acid / Q000097:blood / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000378:metabolism / Q000517:prevention & control*; D003692:Delayed-Action Preparations; D005260:Female; D007476:Ionophores / Q000008:administration & dosage*; D007662:Ketosis / Q000097:blood / Q000378:metabolism / Q000517:prevention & control / Q000662:veterinary*; D007774:Lactation; D016014:Linear Models; D008892:Milk / Q000737:chemistry; D008985:Monensin / Q000008:administration & dosage*; D011247:Pregnancy; D011934:Reagent Strips
D003692:Delayed-Action Preparations; D007476:Ionophores; D011934:Reagent Strips; D008985:Monensin; D020155:3-Hydroxybutyric Acid