A contribution towards milk enzymes, somatic cell count and bacterial pathogens associated with subclinical mastitis cows milk

الملخص EN

A total of 200 milk samples of 50 clinically healthy dairy cows were collected and examined using California mastitis test (CMT) to detect subclinical mastitis.

Somatic Cell count (SCC) and milk enzymes activities; lactate dehydrogenase (LDH), alkaline phosphatase (ALP), catalase and glutathione peroxidase (GPx) were applied to all samples while bacteriological examination was applied to positive CMT only.

Only 14 cows (28 %) were subclinically mastitic containing 31 mastitic quarters (15.5 %).

The entire 31 SCM milk sample showed elevated aLDH, ALP, catalase and GPx activities ; with averages of 236.9 ± 40.9, 268.5 ± 53.3, 631.6 ± 87.9, and 344.2 ± 43 U / ml, respectively.

Meanwhile 27 (87.1 %) only of them showed elevation in SCC with an average of 9.24 ± 2.0 (×105cells / ml).

Bacteriological examination of milk samples revealed that 21 samples (67.7 %) had different bacterial infections, of which 16 quarters (51.6 %) had single bacterial infections and 5 (16.1 %) had mixed bacterial infections.

The correlations between bacterial infections, SCC and enzymatic activities in SCM milk revealed that the mixed bacterial infections ; especially with S.

aureus+ Str.

Dysgalactiae, showed higher elevation in SCC as well as enzymes activities than single bacterial infections.

In conclusion, enzyme parameters in this study can be used as biomarkers for early detection of subclinical mastitis.