Effects of vitamin B6 on the growth performance, intestinal morphology, and gene expression in weaned piglets that are fed a low-protein diet1

Abstract

Vitamin B6 (VB6), which is an essential functional substance for biosome, plays an irreplaceable role in animal health. However, there are few studies that focus on the correlation between VB6 and intestinal health in weaned piglets. This study was conducted to investigate the effects of VB6 on the growth performance, intestinal morphology, and inflammatory cytokines and amino acid (AA) transporters mRNA expression in weaned piglets that are fed a low crude-protein (CP, 18%) diet. Eighteen crossbred piglets with initial body weights of 7.03 ± 0.17 kg (means ± SEM), weaned at 21-d age, were randomly assigned three diets with 0, 4, and 7 mg/kg VB6 supplementation, respectively. The experimental period lasted 14 days. Our results showed that there were no significant differences in growth performance, diarrhea rate, and biochemical parameters among the three treatments. In the jejunum, dietary VB6 supplementation did not affect the morphology and positive Ki67 counts. Dietary supplementation with 4 mg/kg VB6 decreased the mRNA expression of COX-2, IL-10, and TGF-β (P < 0.05). Dietary supplementation with 7 mg/kg VB6 increased the mRNA expression of SLC7A1, SLC7A6, SLC16A14, and SLC38A5 (P < 0.05) and 4 or 7 mg/kg VB6 decreased SLC36A1 mRNA expression (P < 0.05). In the ileum, VB6 supplementation did not affect positive Ki67 counts but significantly decreased villus area (P < 0.05) and tended to decrease villus height (P = 0.093). Dietary supplementation with 4 mg/kg VB6 had significantly increased the mRNA expression of IL-1β, TNF-α, COX-2, IL-10, and TGF-β (P < 0.05). Dietary supplementation with 4 or 7 mg/kg VB6 had significantly decreased SLC6A20, SLC7A1, SLC7A6, SLC16A14, and SLC38A5 mRNA expression (P < 0.05). These findings suggest that dietary supplementation of VB6 mainly down-regulated inflammatory cytokines and up-regulated AA transporters mRNA expression in jejunum, while up-regulated (4 mg/kg) inflammatory cytokines and down-regulated AA transporters mRNA expression in ileum, which may provide a reference for the intestinal development of weaned piglets that are fed a low-CP diet.

Effects of dietary energy levels on rumen fermentation, microbiota, and gastrointestinal morphology in growing ewes

“…The rumen was separated from each sheep, and approximately 100 ml of rumen content was collected and transferred into two 50 ml sterile plastic tubes and then immediately stored at −80°C. A 1 × 1 cm section of the rumen wall was cut, approximately 2 cm long intestinal tissues (duodenum, jejunum, and ileum) from the middle sections were isolated and flushed with ice‐cold phosphate‐buffered saline, and then all the samples were immediately fixed in 4% neutral formalin for morphometric analysis (Yin et al., 2020).…”

Low-Protein Diet Supplemented with Medium-Chain Fatty Acid Glycerides Improves the Growth Performance and Intestinal Function in Post-Weaning Piglets

“…The level of protein is an important factor affecting the growth performance and intestinal health of piglets [ 14 , 15 ]. The undigested protein of piglets will enter the large intestine for fermentation in order to produce toxic metabolites, which will destroy the integrity of the intestinal epithelium and damage the health of the intestinal tract [ 16 ]. Many studies have shown that reducing protein levels can reduce the diarrhea rate and N excretion of piglets, and can reduce protein fermentation in the intestinal tract [ 17 , 18 ].…”

Dietary high protein-induced diarrhea and intestinal inflammation by activation of NF-κB signaling in piglets

“…All experiments in the present study were conducted according to the guidelines of animal welfare in China, and the experimental design and procedures were reviewed and approved (Approval number 2016-093) by the Animal Care and Use Committee of Hunan Normal University, Changsha, Hunan province, China ( Yin et al., 2020 ).…”