Results: On the last day of FR in early lactation, a reduction in milk yield and changes in serum metabolites compared to
respective previous values were detected. The FR in mid-lactation resulted in no changes in milk production and serum
metabolites. Milk cortisol was highest during first wk of lactation and remained on comparable levels thereafter. Milk yield
and composition were not influenced by FR. Lameness resulted in enhanced milk cortisol levels.
Conclusion: Milk cortisol could be used as an indicator of painful symptoms such as lameness. Higher values of milk
cortisol levels during first wk of lactation should be taken into account for interpretation.