**7. Conclusions**

*Animal Reproduction in Veterinary Medicine*

(**Figure 1**). The pathogen risk factors include type (bacteria, fungi, yeast, and algae), number (large number and small number), virulence (highly, moderate, or less virulent), frequency of exposure (dirty farm floor, dirty milking machine, and dirty teat drying towels frequently expose to pathogen; clean floor, clean milking machine, and clean teat drying towels less exposure to pathogens), ability to resist flushing out of the glands by milk (ability to adhere or attach to and invade or internalize into mammary epithelial cells), zoonotic (transmit from cow to human or vice versa) potential, and resistance to antimicrobials [4] (**Figure 1**). The warm, humid, and moist climate favors the growth of bacteria and increases the chances of intramammary infection (IMI) and mastitis development [154]. The incidence of mastitis varies from farm to farm due to the combined effects of these different

*Risk factors for mastitis. SA, Staphylococcus aureus; EC, Escherichia coli; SU, Streptococcus uberis; SCC,* 

Dairy cows are highly susceptible to IMI during the early dry period due to increased colonization of teat skin with bacteria. Bacterial colonization of teat increases during the early dry period because of an absence of hygienic milking practices including pre-milking washing and drying of teats [155], as well as preand post-milking teat dipping in antiseptic solutions [156, 157] that are known to reduce teat end colonization and infection. An udder infected during the early dry period usually manifests clinical mastitis during the transition period because of increased production of parturition inducing immunosuppressive hormones [158, 159], negative energy balance [160], and physical stress during calving [161].

Mastitis is increasingly becoming a public health concern due to the ability of the causative bacterial pathogens and/or their products, such as enterotoxins, to

factors that increase the risk of disease development.

*somatic cell count; AMR, antimicrobial resistance.*

**6. Role of mastitis on public health**

**158**

**Figure 1.**

Bovine mastitis is the most important multifactorial disease of dairy cattle throughout the world. Mastitis is responsible for huge economic losses to the dairy producers and milk processing industry due to reduced milk production, alterations in milk composition, discarded milk, increased replacement costs, extra labor, treatment costs, and veterinary services. Many factors including pathogen, host, and environment can influence the development of mastitis. Mastitis, the inflammation of the mammary gland is usually a consequence of adhesion, invasion, and colonization of the mammary gland by one or more mastitis pathogens such as *Staphylococcus aureus*, *Streptococcus uberis*, and *Escherichia coli*.
