Bovine fecal biomarkers of intestinal inflammatory process: Calprotectin and lactoferrin, a comparative study.

Fecal lactoferrin and fecal calprotectin have been proposed as biomarkers of intestinal inflammation in several animal species. The main objectives of this work were to validate an analytical procedure for the measurement of lactoferrin in calf feces, to study the correlation between lactoferrin and calprotectin concentrations, and to evaluate the influence of fecal water content in the determination of these proteins. This knowledge is essential for effectively using these biomarkers in young calves exposed to inflammatory gastrointestinal diseases.Seventy-eight male Holstein dairy calves between two and three weeks of age were included in the study. Lactoferrin was determined with a bovine milk lactoferrin ELISA kit and calprotectin was measured using a human immunoturbidimetric method previously validated in bovine feces. Analytical validation of the lactoferrin assay achieved good results, with intra and inter assay CV < 10 %, recovery rates between 80 and 120 %, and optimal linearity under dilution. A robust correlation was observed between fecal calprotectin concentrations in dry and wet feces (r = 0.903), while a moderate correlation was observed for fecal lactoferrin concentrations (r = 0.648). Correlation between both biomarkers was moderate in fresh feces (r = 0.514) as well as in dry feces (r = 0.561). In conclusion, the lactoferrin ELISA kit is valid for its use with calf fecal samples, both biomarkers showed a moderate correlation between them, and fecal lactoferrin concentration is more influenced by feces moisture than fecal calprotectin concentration.