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Objective: 1) to establish the BI-IB values in urine of apparently healthy (AHC) and sick (ASC) dairy cows, 2) to estimate of subclinical and clinical ketosis, 3) to determine the effect of season on urinary 13H8 concentration, 4) to compare three diagnostic methods for detection of BHB.
Design: Observational study.
Animals: Purbred or hybrid Holstein dairy cows.
Procedure: 84 urine samples were collected in different season from industrial dairy herds (60 samples, AHC group) and the dairy cows of Veterinary clinical of the Urmia University (24 samples, ASC group). BHB concentrations were assessed by dry and wet rotheras’ test and spectrophotometer. The number of samples in autumn, winter, sprig and summer were 13, 27, 30 and 14 respectively.
Statistical analysis: Chi-Square and ANOVA test.
Results: ANOVA test showed significant and analysis differences ANOVA test between ASC and Al-IC groups and seasons. For ASC group, the highest BHB was observed in winter (2.33±0.76 mmol/l) and the lowest in summer (0.04±0.02 mmol/l). No differences were detected among the three diagnostic methods, but the greater error was observed in dry rothera’s test. The sensitivity and specificity for dry rothera test were 53.2%, 70.3%, and for wet rothea were 78.8% and 89. 1%, respectively. After BHB concentration was classified as 0.2 mmol/l (physiological status), 0.21-1.4 mmol/l (suspected subclinical), 1.4.1 -3mmol/l (subclinical) and over 3 mmol/l (clinical ketosis), the distribution was 59.5% (50), 22.6% (19), 11.9% (10) and 6% (5), respectively. In ASC group, only 5 clinical ketosis was detected, while in Al-IC group 6 subclinical ketosis was observed in winter.
Conclusion: It is concluded that the apparently sick cows have some degree of secondary ketosis. Secondly, the probability of subclinical ketosis in industrial dairy cows of Urmia is not rejected. Thirdly, the occurrence of hyperketonuria in winter could be a problem and finally, after spectrophotometry method, the wet rothera,s method could be an appropriate diagnostic method for field test of ketosis. J. Fac. Vet. Med Univ. Tehran. 57, 1: 57-60, 2002.