Dietary supplementation of encapsulated organic acids enhances performance and modulates immune regulation and morphology of jejunal mucosa in piglets

Effects of dietary supplementation of bovine lactoferrin on growth performance, immune function and intestinal health in weaning piglets

Weaning is a crucial period in the pig's life cycle, which is frequently followed by gastrointestinal (GI) infections, diarrhea and even death. This study focused on the impact of bovine lactoferrin (bLF) supplementation on the intestinal health of weaning piglets. Weaning piglets (Duroc × Landrace × Yorkshire, 23 days) were randomly allocated into four groups, which included negative control group (CON): basic diet; positive control group (ANT): basic diet + 20 mg/kg flavomycin + 100 mg/kg aureomycin; treatment group bLF-A: basic diet + 1 g/kg bLF; treatment group bLF-B: basic diet + 3 g/kg bLF. The result showed that dietary supplementation of bLF can improve growth performance and reduce diarrhea, which exhibits dose-dependency (P < 0.05). Compared with CON group, supplementation with bLF significantly improved immunity, and increased villus height and ratio of villus height/crypt depth at the small intestinal mucosa (P < 0.05). The mRNA expression of claudin-1, occludin and ZO-1 was greatly increased in the ileum of bLF group on days 7 and 14 (P < 0.05). Furthermore, the supplementation of bLF increased the abundance of Lactobacillus and Bifidobacterium and decreased the abundance of Escherichia coli in the cecum on day 7 (P < 0.05). The dietary supplementation of bLF enhanced the growth performance, reduced diarrhea rate in weaning piglets by improving intestinal immunity, morphology and barrier function, balancing intestinal microbiota. And bLF can be a promising feed additive in relieving stress situation of weaning piglets.

Microencapsulated essential oils combined with organic acids improves immune antioxidant capacity and intestinal barrier function as well as modulates the hindgut microbial community in piglets

Background

The objective of this experiment was to evaluate the effect of a combination of microencapsulated essential oils and organic acids (MOA) on growth performance, immuno-antioxidant status, intestinal barrier function and microbial structure of the hindgut in piglets. A total of 120 piglets (Duroc × [Landrace × Yorkshire]; weighted 7.66 ± 1.79 kg, weaned at d 28) were randomly selected and allocated to 3 treatments with 4 replicates per group and 10 piglets per replicate according to the initial body weight and gender. The dietary treatments were as follows: 1) basal diet (Ctrl); 2) Ctrl + chlortetracycline (75 mg/kg) (AGP); 3) Ctrl+ MOA (1500 mg/kg). The experiment period was lasted for 21 d.

Results

Compared to the Ctrl group, dietary supplemented MOA alleviated (P < 0.05) the diarrhea rate from d 12 to 21, enhanced (P < 0.05) the concentration of serum interlukin-10 and glutathione peroxidase in piglets on d 11 after weaning and serum superoxide dismutase in 21-day piglets. The MOA group also improved (P < 0.05) the apparent digestibility of dry matter (DM), organic matter (OM) and gross energy (GE), up-regulated (P < 0.05) the mRNA expression level of occludin, claudin-1 and mucin-2 in ileum and increased (P < 0.05) the contents of propionic and butyric acids in the cecum of piglets. The MOA group modulated the cecal and colonic microbial community structure and increased (P < 0.05) the abundance of Faecalibacterium and Muribaculaceae in cecum and Streptococcus and Weissella in colon. Additionally, AGP group decreased (P < 0.05) apparent digestibility of DM, OM and GE as well as down-regulated (P < 0.05) relative gene expression level of claudin-1 in duodenum and jejunum, ZO-1 and mucin-1 in jejunum of piglets.

Conclusion

In summary, dietary supplemented MOA alleviated diarrhea and improved nutrient apparent digestibility in piglets via enhancing immuno-antioxidant properties, increasing digestive enzyme activity, up-regulating the expression of intestinal barrier-related genes, and modifying the microbial community structure of the cecum and colon. Therefore, dietary supplementation with MOA as an alternative to antibiotics was feasible to improve intestinal health of piglets in practical production.

Effect of Probiotics and Herbal Products on Intestinal Histomorphological and Immunological Development in Piglets

The aim of the study was to evaluate the effect of probiotics and herbal products on the intestinal histomorphological and immunological development in piglets. Accordingly, 2-week-old piglets were allocated in 4 groups: C (basal diet), Pro (basal diet + probiotics), Pro+B (basal diet + probiotics + buckwheat bran), and H (powder of herbs). After 6 weeks of the experiment, 4 piglets from each experimental group were randomly selected and slaughtered at a slaughterhouse. Samples of tissue and digestive content from the jejunum and colon were collected for bacteriological, histological, and immunohistochemical examination. The results showed that probiotics increased the number of Lactobacillus spp. in the small (p < 0.05) and large intestines. The intestinal histomorphology was improved (p < 0.05) in all experimental groups by an increased villus height, VH : CD ration, colon crypt depth, and number of Ki-67⁺ epithelial cells. A higher number (p < 0.05) of goblet cells and their acidification were observed in group Pro, while the density of goblet cells was decreased by the herbs. Probiotics increased (p < 0.05) the number of intraepithelial lymphocytes (IELs), density of CD3⁺ cells in Peyer's patches (PPs), and lamina propria (LP). In group H, a dual effect on the CD3⁺ cell distribution was observed. The herbs reduced (p < 0.05) the number of IELs and CD3⁺ in LP but increased the distribution of CD3⁺ cells in PPs. In the colon, herbs increased CD3⁺ cells in LP as well. It suggests that probiotics and herbs had influence on the intestinal histomorphology and the ability to modulate the mucosal immune system; however, the combination of probiotics and buckwheat bran was not so convincing, probably due to the inhibitory effect of the buckwheat bran on the probiotics used.

Effects of Dietary Supplementation with Mulberry (Morus alba L.) Leaf Polysaccharides on Immune Parameters of Weanling Pigs

In this study, the effect of dietary supplementation of mulberry leaf polysaccharides (MLPs) on the immune parameters-i.e., the immune organ weight, serum immunoglobulins, cytokines, nitric oxide (NO) production, and insulin-Like growth factor-1 (IGF1) mRNA expression-of weanling pigs as a model animal was investigated. A total of 120 healthy weanling pigs (aged 28 ± 2 d) with the same body weights were randomly divided into four groups: (1) Control treatment (CT), basal diet (BD), (2) MLP low-dose treatment (MLT), 0.6 g/kg MLP + BD, (3) MLP high-dose treatment (MHT), 1.2 g/kg MLP + BD, and (4) antibiotic treatment (AT), 0.15 g/kg chlortetracycline + BD. The results revealed that the thymus and spleen indices were significantly increased (P < 0.05) in both MLT and MHT groups in comparison with the CT group, while the serum levels of immunoglobulin G (IgG), interleukin (IL)-1β, IL-2, IL-8, and interferon (IFN-γ) in the MLT group and IL-2, IL-6, and IFN-γ in the MHT group were also considerably greater (P < 0.05) than the corresponding levels in the CT group. The serum contents of IgG, IL-1β, IL-2, and IL-8 in the MLT group and IL-2 and IL-6 in the MHT group were significantly increased in comparison with the corresponding contents in the AT group (P < 0.05). The transformation rate of lymphocytes in the MLT and MHT groups was higher compared to the CT and AT groups. However, a notable difference was found between the MLT group and the two control groups. The peripheral lymphocyte NO production in the MLT, MHT, and AT groups was significant relative to the CT group. The expression levels of IGF1 mRNA in the liver and muscle longissimus tissues of both the MLT and MHT groups showed significant improvement (P < 0.05) over those in the CT group. Moreover, the IGF1 mRNA expression in the muscle longissimus from the MLT group was significantly higher than in the AT group. In conclusion, the results suggest that incorporating MLPs into the diets of weanling pigs improves the animals' metabolisms and immune functions, and the effects of the MLT group were superior to those of both the MHT and AT groups.

Effects of Lactococcus lactis MG1363 producing fusion proteins of bovine lactoferricin-lactoferrampin on growth, intestinal morphology and immune function in weaned piglet

AIMS

We developed a strategy for localized delivery of the LFCA (lactoferricinlactoferrampin), which is actively synthesized in situ by Lactococcus lactis (pAMJ399-LFCA/LLMG1363), and explored the possibility of using pAMJ399-LFCA/LLMG1363 as an alternative additive diet to antibiotics.

METHODS AND RESULTS

The antimicrobial activities of the LFCA derived from pAMJ399-LFCA/LLMG1363 were tested in vitro. The results showed that LFCA had an inhibitory effect on Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. Then, the pAMJ399-LFCA/LLMG1363 was used as an additive diet for piglets. Our data demonstrated that oral administration of pAMJ399-LFCA/LLMG1363 significantly improved the average daily gain, feed-to-gain ratio, intestinal mucosal integrity and decreased the serum endotoxin and d-lactic acid levels. The mRNA expression levels of intestinal tight junction proteins (including occludin, Claudin-1 and ZO-1) were significantly upregulated by pAMJ399-LFCA/LLMG1363 administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, IL-2, IL-10 and TGF-β levels were significantly increased by pAMJ399-LFCA/LLMG1363. Furthermore, our data revealed that oral administration of pAMJ399-LFCA/LLMG1363 significantly increased the number of general Lactobacillus, and decreased the total viable E. coli counts in the ileum and cecum contents.

CONCLUSIONS

We developed a novel pAMJ399-LFCA/LLMG1363 secreting LFCA, which had probiotic effects on the growth performance, intestinal morphology, intestinal barrier function and immunological indices of weaned piglets.

SIGNIFICANCE AND IMPACT OF THE STUDY

pAMJ399-LFCA/LLMG1363, with probiotic effects on the health of weaned piglets, may be a promising feed additive for weaned piglets.