**5. Economic impacts due to** *S. aureus* **udder infection**

Economic impacts of the mastitis are of great financial importance. Mastitis negatively impacts numerous aspects of cow and herd management. Mastitis can incur economic losses in both ways either directly and indirectly [9]. The direct costs include veterinary expenditure, labor costs, reduced production, poor quality milk and discarded milk. Whereas, the indirect losses are not obvious to the producers and are termed as "hidden costs" which include increased risk of other diseases, poor fertility rate, increased culling rate and sometime mortality. So, total cost can be much more than the direct losses [10–12].

A 15–20% of total cow population of the countries having major share in the milk production is affected by mastitis each year. Production losses per effected quarter are estimated 30% of productivity loss whereas, 15% production is lost during entire lactation/cow. The mastitis rate in the heifer can be up to 97% and *S. aureus* has major significance in imparting the huge economic losses. *Staphylococcus aureus* effects animals of various stage and parity e.g. nulliparous, primiparous, primigravid and multiparous [42, 43].

In Holland, the financial losses resulted due to clinical mastitis by Staphylococci were €293/Cow. Whereas, it was €277/cow in every clinical case of mastitis due to staphylococci in first three months after post calving and €168/cow onward for the rest of the lactation. In USA dairy, the annual losses incurred by the mastitis were estimated around \$2billions, while \$400 M in Canada and \$130 M in Australia excluding the antibiotic residue in human diet, expense to preserve the nutritive quality of milk and to prevent milk degradation [12, 44, 45]. There is variation in cost of each component between the herds, partially due to the performance of herd and partially due to difference in preferences of the farmers when the mastitis is detected. Mastitis can impart economic losses to the farmers in following ways.
