Weaning Markedly Affects Transcriptome Profiles and Peyer’s Patch Development in Piglet Ileum

Abstract

Transcriptome analyses were conducted on the ileal mucosa of 14- to 35-day-old piglets to investigate postnatal gut development during suckling and postweaning. The transcriptome profiles of 14-day-old suckling piglets showed a considerably higher number of differentially expressed genes than did those of 21-, 28-, and 35-day olds, indicating an intensive gut development during the first 14–21 postnatal days. In addition, the analysis of biological pathways indicated that Chemotaxis Leucocyte chemotaxis was the most significantly affected pathway in suckling piglets between 14 and 21 days of age. Weaning negatively affected pathways associated with acquired immunity, but positively affected those associated with innate immunity. Interestingly, pathway Chemotaxis Leucocyte chemotaxis was found positively affected when comparing 14- and 21-day-old suckling piglets, but negatively affected in 28-day-old piglets weaned at 21 days of age, when compared with 28-day-old suckling piglets. Genes CXCL13, SLA-DOA (MHC class II), ICAM1, VAV1, and VCAM1 were involved in the pathway Chemotaxis Leukocyte chemotaxis and they were found to significantly change between 14- and 21-day-old suckling piglets and between groups of suckling and weaned piglets. The expression of these genes significantly declined after weaning at 14, 21, and 28 days of age. This decline indicated that CXCL13, SLA-DOA, ICAM1, VAV1, and VCAM1 may be involved in the development of Peyer’s patches (PP) because lower gene expression clearly corresponded with smaller areas of PP in the ileal mucosa of piglets. Moreover, weaning piglets prior to a period of intensive gut development, i.e., 14 days of age, caused significant adverse effects on the size of PP, which were not reverted even 14 days postweaning.

Impact of TGEV infection on the pig small intestine

“…Proper development of the pig gut is not only associated with feeding efficiency, but also with susceptibility to pathogens throughout life. Maldevelopment of the small intestine in TGEV-infected pigs may decrease absorptive capacity and result in a lower feed conversion rate [12]. Our results demonstrated that the cause of impaired growth in TGEV-infected pigs is very likely due to the changes in intestinal morphology and in other characteristics.…”

Production, Absorption, and Blood Flow Dynamics of Short-Chain Fatty Acids Produced by Fermentation in Piglet Hindgut during the Suckling–Weaning Period

“…The 32 piglets used in the present study are shown in Table 1 . The crossbred (Landrace × Large white × Duroc) piglets used in the present experiment were the same as those described in a previous study [ 13 ], except for piglets weaned at 14 days of age, which were omitted in the present work because we demonstrated that weaning at such age is not commercially practical for the pig industry [ 12 , 13 ]. All piglets were raised at the Toyohashi Feed Mills Technical Center (Shinshiro, Aichi, Japan).…”

“…Weaning, which occurs for all newborn mammals, can be a very stressful event. For example, it has been observed that the intestinal structure and function of piglets are drastically affected by weaning [ 12 , 13 ]. Moreover, during weaning, the transition from maternal milk to solid food affects not only the structure and function of the intestine but also the components of the luminal environment such as the intestinal microbiota and its metabolites.…”

“…Age at weaning age is one of the important factors for a good post-weaning development of pigs. In our previous study, early weaning at 14 days of age caused functional and morphologic ateliosis in piglets [ 12 , 13 ]. It is worth noting that marked maturation of the mucosal structure and function took place in 14- and 21-day-old suckling piglets [ 12 ].…”

“…In our previous study, early weaning at 14 days of age caused functional and morphologic ateliosis in piglets [ 12 , 13 ]. It is worth noting that marked maturation of the mucosal structure and function took place in 14- and 21-day-old suckling piglets [ 12 ]. Therefore, it is likely that age at weaning may also affect the ability of the intestine to absorb SCFA.…”