Cut-off values for predictors associated with outcome in dairy calves suffering from neonatal calf diarrhea. A retrospective study of 605 cases

•Clinical data of 605 diarrheic calves were evaluated to identify predictors associated with outcome.•Calves with total serum protein (STP) >50 g/L had greater odds of surviving.•Disease severity did not influence the relationship between STP concentration and outcome.•Based on dehydration degree STP cut-off value ranged between 45 and 55 g/L.•None of the markers used had great predictive ability to assess mortality risk.