Feeding colostrum, its composition and feeding duration variably modify proliferation and morphology of the intestine and digestive enzyme activitiesof neonatal calves

We studied the effects of amounts of colostrum consumed on intestinal morph ology and proliferation and digestive enzyme activities in neonatal carves. Group GrC(max) calves were fed colostrum from the first milking undiluted on d 1-3 and diluted with 25, 50, 75 and 75 parts of a milk replacer on d 4 -7. Group GrC(1-3) calves were fed colostrum from milkings 1-6 up to d 3 an d then a milk replacer up to d 7. Group GrF(1-3) carves were fed a milk-bas ed formula (containing only traces of growth factors and hormones) up to d 3 and then a milk replacer up to d 7. Calves were killed on d 8. Difference s in feeding affected villus sizes and villus height/crypt depth ratios in the duodenum (GrC(max) > GrC(1-3)), villus areas and villus height/crypt de pth ratios in the jejunum (GrC(1-3) > GrF(1-3)) and crypt depths in the col on (GrF(1-3) > GrC(1-3)). Furthermore, different feeding protocols affected the proliferation rates of epithelial cells in the duodenum (GrC(1-3) > Gr C(max); GrC(1-3) > GrF(1-3)) and the jejunum (GrF(1-3) > GrC(1-3)) based on Ki-67 labeling). Lipase activities in the pancreas were influenced by colo strum feeding (GrC(max) > GrC(1-3)) Colostrum intake differentially affecte d intestinal epithelial surface and proliferation and enzyme activities. Fe eding high amounts of first colostrum seemed to enhance the survival of mat ure mucosal epithelial cells in selected parts of the small intestine, wher eas the lack of colostrum seemed to decrease epithelial growth.