© 2019 Elsevier LtdEndotoxemia treatment options are still of interest due to high mortality and choline treatment is one of them because of its role in the cholinergic anti-inflammatory pathway. This study investigated serum choline and butyrylcholinesterase (BChE) responses, and their correlations with inflammatory, oxidative stress and tissue damage biomarkers, including paraoxanase-1 (PON1), and clinical signs in calves with endotoxemia and the effect of choline treatment in these responses. Healthy calves (n = 20) were divided equally into 4 groups: Control (0.9% NaCl, iv), Choline (C; 1 mg/kg/iv,once), Lipopolysaccharide (LPS; 2 μg/kg/iv,once) and LPS + C. Clinical and laboratory examinations were performed before and 0.5–48 h (hrs) after treatments. Following LPS administration, serum choline level increased at 0.5-24 h (P <.01), whereas serum BChE and PON1 level decreased at 48 h (P <.01) compared to their baselines. In LPS + C group, the increase in serum choline level was significantly higher (P <.01) than that of C and LPS groups. LPS did not decrease serum BChE levels significantly in calves treated with choline. Serum choline and BChE results correlated negatively with white blood cell count and positively (P <.001) with PON1 levels, oxidative stress index, inflammation and hepato-muscular injury markers. In conclusion serum choline and BChE may have a role in the pathophysiology of endotoxemia in calves. High serum choline concentration is associated with an improvement in response to LPS administration in calves treated with choline, probably by preventing the imbalances between oxidative stress and anti-oxidant capacity, preventing the serum BChE and PON1 decreases, and inhibition/attenuation of acute phase reaction and hepato-muscular injury in calves with endotoxemia.