The relationship between preweaning diarrhea frequency and intestinal permeability and blood glucagon-like peptide-2 concentration in dairy calves.

This study aimed to evaluate the associations of diarrhea frequency on intestinal permeability, plasma glucagon-like peptide-2 (GLP-2) concentration, and growth performance in dairy calves. Twenty-two Holstein calves were monitored from birth to postweaning and classified into high (H) and low (L) diarrhea groups based on the number of days with diarrhea (top and bottom 25%, respectively: n = 6). Fecal consistency was scored on a 4-point scale ranging from 0 to 3, and diarrhea was defined as a fecal score ≥2, with total days of diarrhea ranging from 19 to 36 d in the H group and from 3 to 5 d in the L group throughout the 66-d experimental period. To evaluate the intestinal permeability, the Cr-EDTA test was assessed by oral administration of Cr-EDTA followed by blood sample collections at 28, 42, and 63 d of age. At 0, 1, 5, 28, 42, 49, 56, and 66 d of age, blood GLP-2 concentrations were measured. Although no differences in intestinal permeability were detected between groups, plasma GLP-2 concentrations were consistently higher in the L group throughout the observation period. In addition, despite no differences in solid feed intake between groups, ADG was greater in the L group than in the H group. These findings suggest that plasma GLP-2 concentrations may be associated with postweaning ADG, even in the absence of detectable changes in intestinal permeability.