Stages of Gut Development as a Useful Tool to Prevent Gut Alterations in Piglets

Abstract

During the prenatal, neonatal, and weaning periods, the porcine gastrointestinal tract undergoes several morpho-functional, changes together with substantial modification of the microbial ecosystem. Modifications of the overall structure of the small intestine also occur, as well as a rapid increase of the volume, mainly in the last period of gestation: intestinal villi, starting from jejunum, appears shortly before the sixth week of gestation, and towards the end of the third month, epithelial cells diversify into enterocytes, goblet cells, endocrine, and Paneth cells. Moreover, in the neonatal period, colostrum induces an increase in intestinal weight, absorptive area, and brush border enzyme activities: intestine doubles its weight and increases the length by 30% within three days of birth. During weaning, intestinal environment modifies drastically due to a replacement of highly digestible sow milk by solid feed: profound changes in histological parameters and enzymatic activity are associated with the weaning period, such as the atrophy of the villi and consequent restorative hypertrophy of the crypts. All these modifications are the result of a delicate and precise balance between the proliferation and the death of the cells that form the intestinal mucosa (i.e., mitosis and apoptosis) and the health conditions of the piglet. An in-depth knowledge of these phenomena and of how they can interfere with the correct intestinal function can represent a valid support to predict strategies to improve gut health in the long-term and to prevent weaning gut alterations; thus, reducing antimicrobial use.

Evaluation of a Dietary Grape Extract on Oxidative Status, Intestinal Morphology, Plasma Acute-Phase Proteins and Inflammation Parameters of Weaning Piglets at Various Points of Time

“…Another interesting observation was seen regarding the effect of the PC, with no effect in the jejunum and an effect in the ileum comparable to those of the GE group. We suppose that the ileum, which generally has a longer recovery time [ 67 ] and a higher number of goblet cells [ 2 ] compared to the jejunum, needed more time post weaning to reach the maturation condition that enabled positive effects of dietary interventions (PC and GE in the present work).…”

“…However, regarding the main effect of diet in the present work, as a result of the similar effects at both sampling points, the PC showed significantly lower crypt surface area compared to the NC. Smaller crypts, in general, reflect lower tissue turnover and a lower demand for villus renewal and tissue synthesis [ 2 ], which indicates overall lower pathogen overload in PC. However, there was no clear effect of any diet at either sampling point, which allows us to infer that the likelihood of infection and the occurrence of pathogens was probably similar, with an overall slight advantage of the PC at some point.…”

“…Tunica muscularis thickness: We measured the thickness of tunica muscularis mucosae with regard to the role of the muscularis layers for gradually moving the luminal contents along the gastrointestinal tract. Adapting to a new type of feed at weaning also affects gut motility [ 2 ]. Peristaltic movement is responsible for the blending of the gut content and increases enzymatic activity on nutrients, thereby affecting the absorption of nutrients [ 70 ].…”

“…Higher villi, increased villus surface area, and increased VC ratio are indicators of the absorption and digestion capability of intestinal villi [ 2 ]. Villus hyperplasia, as achieved by GE and partly by the PC in this study, may be regarded as favourable, as it indicates an absence of undesirable infection features such as villus atrophy [ 1 ].…”

“…Commercial weaning takes place during a time of the still-incomplete maturation of a piglet’s intestine [ 1 ]. This includes the morphological and functional maturation of the intestinal immune and enteric nervous systems [ 1 , 2 , 3 ]. Stressful early-life events, e.g., weaning, may disrupt gut maturation and have long-term consequences for animal health and productivity [ 4 ].…”