A COMPARISON OF MASTITIS DETECTION METHODS IN DAIRY CATTLE

Abstract

The potential value of electrical conductivity, somatic cell count, and California Mastitis Test (CMT) Score in composite milk samples as a screening test for subclinical mastitis was evaluated. The effect of genetic group was significant (P < 0.05) for conductivity and somatic cell count while the effects of parity and month of lactation were significant (P < 0.01) for all the three traits studied. Somatic cell count and CMT score increased from first to fourth parity while there was general trend for increasing conductivity from second to fourth parity. All the three methods identified healthy cows with a good accuracy but failed to recognize a considerable proportion of infected cows. The error rate for misclassification was lowest for CMT score (9.1%), followed by somatic cell count (13.9%) and conductivity (29.4%). Composite strict foremilk samples from cows infected with primary pathogens had significantly (P < 0.01) higher conductivity than those from uninfected cows. Staphylococcus aureus were isolated in 60% of the milk samples and appeared to be in the major organism causing mastitis in this herd. Key words: Dairy cattle, mastitis detection methods