Intestinal IgG uptake by small intestine of goat kid fed goat or lyophilized bovine colostrum

AbstractThe immunoglobulin G (IgG) uptake and enterocyte nucleus position in the villous were studied in newborn goat kids fed goat or lyophilized bovine colostrum. Two groups of 15 newborn goat kids, each received 5% of body weight of goat colostrum (GC) or lyophilized bovine colostrum (LBC) containing 55mg/mL of immunoglobulin G (IgG) at 0, 7 and 14h of life. Three animals were sampled just after birth, receiving no colostrum intake, to be used as control. Samples of duodenum, medium jejunum and ileum were collected at 0, 18, 36 and 96h of life. IgG vacuoles were not observed in the duodenum throughout the experiment regardless of all the experimental time points. In this segment, at 0, 18 and 36h of life, nuclei were found in the apical, medial and basal positions in the enterocytes, and localized in the upper, medial and lower parts in the villous, respectively. At 96h, a basal nuclei position was observed in the enterocytes, throughout the villous. In jejunum, IgG vacuoles were distributed along the villous at 18 and 36h. In this segment at 0h the nuclei were positioned predominantly apically in the enterocytes, throughout the villous. At 18 and 36h, no consistent nuclei pattern was verified; however at 96h, the nuclei were positioned basally in the enterocytes, throughout the jejunal villous. In the ileum at 0, 18 and 36h, a great number of vacuoles without IgG were verified in the medial–apical part of the villous. In this segment, at 0h of life and 96h of life, the predominance of basal nuclei was observed. Nuclei were positioned in medial–apically part of the ileal enterocytes in the upper part of the villous at 18 and 36h. It was found that the jejunal epithelium was the most important segment related to absorption process. The IgG absorption and nucleus position in the newborn goats were dependent on the small intestine segments and experimental time points, regardless of the colostrum source, GC or LCB. Considering the IgG uptake mechanism observed in the present study, the lyophilized bovine colostrum might be used instead of goat colostrum