Objective: 1) Detection of the milk ketonc bodies by wet Rothera and spectrophotometer methods, 2) Comparison of the ketone bodies between two groups, 3) the reliability of bulk milk samples for detection of ketone bodies, 4) the effects of season on milk ketone bodies, and 5) the distribution of sub-clinical and clinical ketosis in industrial and semi-industrial dairy herds. Design: Observational Investigation.
Animals: Purebred and hybrid Holstein dairy cattle from industrial and semi-industrial dairy herds.
Procedure: Milk samples from 2920 industrial and 1430 semi- industrial dairy herds were collected. Milk samples from industrial dairy herds were collected individually from cows and semi- industrial dairy herds collected from bulk milk. Test for milk ketone quality was carried out using wet rothera test and milk sera were tested for beta hydroxy butyric acid (BHB) using a spectrophotometer to measure ketone quantity.
Statistical analysis: Chi-square test.
Results: Thirteen eases from bulk milk was observed positive in rothera test (0.9 1%) and 97 cases from individual cow samples (3.32%). Differences between two groups were significant (P<0.05). Twelve out of 13 affected samples from bulk milk were occurred in autumn and spring wihile 57 eases from individual dairy milk were occurred in winter. Affected eases in individual cow milk in winter was greater (P<0.05) than other seasons in bulk milk and for bulk milk in autumn was greater (P<0.05) than in individual cow milk. The results of BHB test on affected samples (13 and 97) showed that ketone bodies with over 0.05 mmol/l as an indication of subclinical and clinical ketosis to be presented only in 19 cases (0.43%) and the others were in physiological status (<0.05 mmol/l). Of those, 12 cases occurred in winter and in individual cow milk
samples (0.27%), and 6 cases occurred in bulk milk samples during the autumn (0.13%). Mean+Se BHB concentrations in winter and autumn were 0.39+0.06 and 0.24+0/06 mmol/l, respectively. Differences between seasons were significant (P<0.05). Clinical implications: It is concluded that there are differences between the two diagnostic methods of ketone bodies detection in diagnosis of ketosis from physiological status. Bulk milk samples can be reliable for the quality assessment of ketone bodies. Subclinical and clinical ketosis in industrial and semi-industrial dairy herds should not be rejected. Ketone bodies in industrial and semi-industrial dairy herds appeared to be higher in winter and autumn, respectively. Finally a milk field test from industrial and semi-industrial dairy herds might be appropriate for diagnosis of subclinical and clinical ketosis but it is recommended to be supported by quantity method (BHB) as well. J. Fac. Vet. Med. Univ. Tehran. 58, 1: 5-9, 2003