Association between subclinical mastitis pathogens and passive transfer of immunity in calves

Subclinical mastitis, particularly infections caused by <i>S. aureus</i> and <i>E. coli</i>, is associated with increased inflammatory markers and reduced immunoglobulin content in colostrum, leading to impaired passive immune transfer in calves. Elevated Hp and SAA in calves may indicate both passive transfer from colostrum and early activation of the neonatal immune system. These findings highlight the importance of pathogen-driven alterations in colostrum composition and support the potential of Hp and SAA as biomarkers for monitoring subclinical mastitis and predicting calf health outcomes.