The objective of this study was to determine the diagnostic performance of an electronic beta-hydroxybutyrate (BHBA) hand-held meter (Precision Xtra) for use in dairy cattle. Specific objectives were to compare the electronic BHBA meter with serum BHBA concentrations determined photometrically and 2 commonly used chemical cowside tests (Ketostix, Ketolac) and to evaluate accuracy in a field study employing 35 investigators. Of the 196 blood samples collected in experiment 1, 17 (8.7%) contained > or =1,200 micromol of BHBA/L of blood and 10 (5.1%) contained > or =1,400 micromol of BHBA/L of blood. Pearson correlation coefficients were highly significant for all tests. The highest correlation coefficient (0.95) was found between measurements of whole blood BHBA determined with the Precision Xtra test and the serum BHBA concentrations determined photometrically. Correlation coefficients between serum BHBA and BHBA in urine using Precision Xtra and Ketostix, and milk using Ketolac were lower. The Precision Xtra test was both 100% sensitive and specific at > or =1,400 micromol of BHBA/L of whole blood. Using milk and urine, positive and negative predictive values were considerably lower for both chemical tests as well as for the electronic meter. In the second study undertaken with 35 bovine veterinary practices, 926 blood samples were collected. In this study, the Precision Xtra test had sensitivities of 88 and 96% at 1,200 and 1,400 micromol of BHBA/L of whole blood, respectively. Specificities were 96 and 97%, respectively. Level of agreement was lower in the second study employing multiple investigators. Considerable differences in variance occurred among investigators. We conclude that the electronic hand-held BHBA measuring system using whole blood is a useful and practical tool to diagnose subclinical ketosis. Sensitivity and specificity are excellent for a cowside test and higher than 2 commonly used chemical dipsticks (Ketostix and Ketolac).

No abstract

The objective of this field trial was to evaluate effects of a single administration of 2.2 mg/kg of body weight (BW) of flunixin meglumine (FM) in addition to a systemic antibiotic treatment in cows with acute puerperal metritis (APM). Outcome variables tested were proportion of cows with a fever, prevalence of chronic endometritis 18 to 22 and 32 to 35 d in milk (DIM), and reproductive performance measures in the current lactation. In addition, serum concentrations of haptoglobin and fibrinogen were analyzed. Daily milk yield within 6 d after the first treatment was recorded. Cows were examined 4 to 5 DIM by rectal palpation and vaginoscopy, and rectal temperature was measured. Fetid vulvar discharge and a body temperature > or = 39.5 degrees C were signs of APM. Cows with APM were treated in the reference group with 1.0 mg/kg of BW of ceftiofur on 3 to 5 consecutive days (CEF, n = 119). In the study group, cows received the same antibiotic treatment as in CEF and 2.2 mg/kg of BW of FM on treatment d 1 (CEF + FM, n = 119). Blood samples were collected 4, 6, and 10 DIM and analyzed for concentrations of haptoglobin and fibrinogen. A group of cows without APM remained untreated and served as controls (n = 9). There were no significant differences between CEF and CEF + FM in the proportion of cows with fever 1 d after the first treatment (33.6 vs. 46.2%), milk yield per milking 10 DIM (7.5 +/- 0.3 vs. 7.6 +/- 0.3 kg in primiparous, 9.6 +/- 0.4 vs. 10.6 +/- 0.4 kg in multiparous cows), prevalence of chronic endometritis 32 to 35 DIM (64.3 vs. 52.2%), and in reproductive performance (31.5 vs. 34.3% conception to first AI, 58.0 vs. 54.6% pregnancy rate, 107.8 +/- 36.9 vs. 101.6 +/- 41.4 d open). Compared with the control, CEF and CEF + FM had significantly greater concentrations of haptoglobin (1.1 +/- 0.28 vs. 1.9 +/- 0.06 and 1.8 +/- 0.07 mg/mL at 4 DIM; 0.3 +/- 0.15 vs. 1.1 +/- 0.06 and 1.2 +/- 0.07 mg/mL at 10 DIM) and fibrinogen (2.2 +/- 0.17 vs. 3.9 +/- 0.14 and 3.7 +/- 0.13 g/L at 4 DIM; 1.9 +/- 0.1 vs. 2.6 +/- 0.1 and 3.0 +/- 0.13 g/L, respectively, at 10 DIM) on all test days. The additional treatment with FM had no effect on these acute phase proteins. In conclusion, the single administration of 2.2 mg/kg of BW of FM in addition to a systemic antibiotic treatment of cows having APM did not result in beneficial effects on clinical cure, milk yield within 6 d after the first treatment, or reproductive performance.

Bacteria are the main causative agents of clinical mastitis. However, 10 to 40% of milk samples obtained from mastitic quarters are negative on culture. Lactoferrin, lysozyme and the lactoperoxidase system (LPS) are milk ingredients that are known to inhibit bacterial growth. It was the objective of this study, to analyse the possible role of lactoferrin, lysozyme and the lactoperoxidase system as growth inhibitors in milk samples from quarters with clinical mastitis. Lactating dairy cows (n=75) with clinical mastitis on a commercial dairy farm were included in the study. Cows were examined clinically and milk samples were collected from the quarter affected by clinical mastitis (clinical quarter) and the opposite quarter (control quarter). Samples were submitted for microbiological examination and were tested for activity of the LPS using spectrophotometry. Samples were stored at -20°C until examined for concentration of lactoferrin using an ELISA. Lysozyme was determined using the "lyso plate" technique (inhibibition of growth of Micrococcus lysodeicticus suspended in agar). Contents of all three milk constituents were significantly higher in the samples collected from clinical quarters than from control quarters. Clinical signs were on average more severe in cows with positive samples than in those with negative samples. Lactoferrin content and LPS activity did not differ between samples that yielded bacterial growth (positive samples) on culture and sterile samples. Lysozyme content was even higher in positive than in negative samples. It is concluded that the three milk constituents measured play a negligible role in the origin of the failure to identify the causative agent of mastitis cases in dairy cows. Abstracts -Oral presentations at 11 th ICPD 185Acta vet. scand. Suppl. 98 -2003