Abstract
Mastitis is a common disease that decreases milk yield and quality in lactating cows. Because of higher treatment cost and higher culling rate, mastitis causes economical losses. The CMT test was used to detect infection of mastitis in the farms; the infection is detected in 55.16% of cattle herd. The responsible infections bacteria suspected mastitis were determined. The bacteriological analysis revealed the presence of varied dominant bacteria belonging to the species of Staphylococcus aureus (30.76%), Streptococcus sp. (30.76%) and Escherichia coli (23.07%). These bacterial species were responsible for the infection of the cow in the different samples The milk acidity was variable so that almost half of the samples were at pH (6.65-6.90). The establishment of a guide to monitoring and surveillance is essential for control of pathogenic bacteria.