Effect of Subclinical Mastitis on Fibrinogen, Orotic Acid and Some Enzymes in the Milk of Dairy Cows.

The present study was undertaken to investigate the effect of subclinical mastitis on some indicators of inflammation in milk, and their correlation with somatic cell count (SCC) in cattle. A total of 20 lactating cows positive for subclinical mastitis and equal number of cows negative for subclinical mastitis by both modified California mastitis test (MCMT) and somatic cell count (SCC) were examined for the levels of fibrinogen, orotic acid and some of milk enzymes. Cows having subclinical mastitis were found to have significantly higher levels of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and aspartate amino transferase (AST) activity in the milk in comparison to the control cows. Fibrinogen and orotic acid levels in subclinical mastitis (SCM) milk were also significantly higher than that of healthy cows. Milk somatic cell count (SCC) showed highest correlation with ALP (r = 0.83, P < 0.01) followed by LDH (r = 0.71, P < 0.01) and AST (r = 0.70, P < 0.01). Fibrinogen, an acute phase protein (r = 0.79, P < 0.01) and orotic acid (r = 0.88, P < 0.01), an intermediate metabolite also had significant positive correlation with SCC. Thus, among all 5 indirect indicators of inflammation, ALP could be considered as most economical and sensitive marker of subclinical mastitis. Therefore, it could be used for early detection and control of SCM in dairy herds. [ABSTRACT FROM AUTHOR]