Mean ± SD plasma total protein concentration (left panel) and IgG concentration (right panel) in 24 Holstein‐Friesian calves receiving 3 L of pooled colostrum containing acetaminophen (50 mg/kg) by suckling and oroesophageal intubation. Treatments were: 2 mL of 0.9% NaCl solution PO (control treatment; n = 6, open circles); 2 mL of water containing erythromycin lactobionate (20 mg/kg BW, PO; n = 6, filled circles); 2 mL of water containing cisapride (0.5 mg/kg BW, PO; n = 6, filled triangles); and 2 mL of water containing bethanechol chloride (0.5 mg/kg BW, PO; n = 6, filled squares). Data are slightly offset for each group with respect to time to improve readability. †P < .0055 (Bonferroni corrected) for the specific treatment compared with control treatment at the same time.