Effect of yeast-derived products on systemic innate immune response of broiler chickens following a lipopolysaccharide challenge

Effects of Dietary Brown Rice and Sake Lees on the Growth Performance and Color of Meat in Broiler Chicks

In this study, we examined whether brown rice and sake lees (domestic feed ingredients) could replace corn and soybean meal (major imported feed ingredients) in broiler chick feed. In Experiment 1, 21-day-old broiler chicks were assigned to two groups and fed a corn-soybean- or a brown rice-soybean-based diet for three weeks (3 birds × 4 replicates/group). Dietary brown rice significantly improved body weight gain and feed conversion ratio. Brown rice feeding also significantly increased L* (lightness) in the thigh and significantly decreased a* (redness) and b* (yellowness) in the thigh and b* in the fat. In Experiment 2, 21-day-old broiler chicks were assigned to three groups and fed either a corn-soybean-based diet for 3 weeks, a corn-soybean-based diet for the first 2 weeks followed by a brown rice sake lees-based diet for the last week, or a brown rice sake lees-based diet for 3 weeks (3 birds × 4 replicates/group). Replacement of the imported feed ingredients significantly improved the feed conversion ratio. The a* values for the breast, thigh, and fat, and the b* values for the thigh and fat were significantly decreased by rice and sake lees feeding for 3 weeks. The a* values for the breasts and fat were significantly decreased by rice and sake lees feeding for 1 week. These results suggest that brown rice and sake lees can be used as replacements for imported feed ingredients such as corn and soybean meal in broiler chicks without detrimental effects on growth performance. These domestic feed ingredients may benefit local production and consumption of poultry in Japan.

Influence of dietary mannan-oligosaccharides supplementation on hematological characteristics, blood biochemical parameters, immune response and histological state of laying hens

This study aimed to determine the influence of dietary mannan-oligosaccharides (MOS) on the immune system, hematological traits, blood biochemical parameters, and histological state of laying hens. At 34 wk of age, The Mandarah chicken strain's 120 laying hens and 12 cocks were divided into 4 groups, each with 30 hens and 3 cocks. The first group performed as a control group, which nourished on a basal diet. The second, third, and fourth experimental groups received 0.1, 0.2, and 0.5 g/kg of MOS and a base diet, respectively. Birds obtained MOS at numerous doses significantly (P ˂ 0.05) raised serum levels of immunoglobulin Y (IgY), immunoglobulin M (IgM), and avian influenza (AI) antibodies compared to control birds. Furthermore, adding MOS at a level of 0.1 g/kg diet significantly improved the immune response of the control group. Additionally, compared to the control group, treated birds with MOS at various dosages did not significantly enhance hematological parameters such as red blood cells (RBCs), white blood cells (WBCs), hemoglobin, and hematocrit. Compared to control birds, birds fed MOS at all levels exhibited considerably lower serum cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) values. Also, compared to other treated birds, MOS-treated birds displayed improved histological examination of the small intestine, isthmus, and testis compared to the control group, particularly in birds fed MOS at 0.1 and 0.2 g/kg diet. It could be concluded that using MOS at 0.1 or 2 g/kg diet can successfully improve the physiological performance and overall health of laying hens.

Dietary yeast cell wall enhanced intestinal health of broiler chickens by modulating intestinal integrity, immune responses, and microbiota

This study was conducted to determine the effects of dietary yeast cell wall (YCW) on growth performance, intestinal health, and immune responses of broiler chickens. In a randomized completely block design (block: initial body weight), a total of 800 broilers (Ross 308; 45.18 ± 3.13 g of initial body weight) were assigned to 2 dietary treatments (40 birds/pen; 10 replicates/treatment) and fed for 5 wk: 1) a basal broiler diet based on corn-soybean meal (CON) and 2) CON + 0.05% dietary YCW. Growth performance was measured at intervals in 3 phase feed program. On the final day of the study, one bird per pen was randomly selected and euthanized for sample collection. Broilers fed YCW had decreased (P < 0.05) feed conversion ratio during the grower phase compared with those fed CON. The YCW increased (P < 0.05) villus height to crypt depth ratio in the duodenum, jejunum, and ileum compared with the CON. In addition, the YCW tended to higher (P < 0.10) number of goblet cells in the duodenum than in the CON. Broilers fed YCW had increased (P < 0.05) serum TGF- β1, ileal gene expression of the claudin family, and relative abundance of Lactobacillus, Prevotella, and Enterococcus compared with the CON, but decreased serum TNF-α (P < 0.05), IL-1β (P < 0.05), and IL-6 (P < 0.10), ileal gene expression of IL-6 (P < 0.05), and relative abundance of Clostridium (P < 0.05). The present study demonstrated that the addition of dietary YCW in broiler diets enhanced the intestinal health of broiler chickens and may be associated with modulated intestinal morphology and integrity by upregulating tight junction-related protein gene expression and modifying the ileal microbiota. In addition, dietary YCW modulated immune responses and inflammatory cytokine gene expression in the ileum.

Gene expression of pro-inflammatory (IL-8, IL-18, TNF-α, and IFN-γ) and anti-inflammatory (IL-10) cytokines in the duodenum of broiler chickens exposed to lipopolysaccharides from Escherichia coli and Bacillus subtilis

Background and Aim

Intestinal infections are associated with Gram-negative bacteria like Escherichia coli. When eliminated by treatments during replication, E. coli release lipopolysaccharides (LPS) that can activate the intestinal immune system and increase the expression of cytokines, such as interleukin (IL)-8, IL-18, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ), by the intestinal epithelium under pathological conditions. This study aimed to evaluate the addition of Bacillus subtilis to the duodenal gene expression of pro-inflammatory and anti-inflammatory cytokines in broilers exposed to LPS from E. coli.

Materials and Methods

RNA was extracted using the Zymo Research total RNA commercial kit, according to the manufacturer's specifications, from the intestinal tissue of the duodenum previously resuspended in the lysis buffer of the kit. The expression of the cytokines of interest was measured using the QuantiNova SYBR green real-time polymerase chain reaction kit (Qiagen). Transcript quantification was performed by the ΔΔC(t) method using glyceraldehyde 3-phosphate dehydrogenase as a normalizing constitutive gene.

Results

For the measurement of pro-inflammatory (IL-8, IL-18, TNF-α, and IFN-γ) and anti-inflammatory (IL-10) cytokines, there was no statistically significant difference (p > 0.05) between the basal diet and the diet with antibiotic (avilamycin). There was a statistical difference (p < 0.05) between diets with LPS. The diet with B. subtilis presented the lowest expression; the results differed on each sampling day (days 14, 28, and 42).

Conclusion

A decrease in the expression of pro-inflammatory cytokines (IL-8, IL-18, TNF-α, and IFN-γ) and an increase in IL-10 (anti-inflammatory) was observed; in this way, a balance of the inflammatory response to bacterial infection is achieved, suggesting that the use of B. subtilis as an additive in a broiler diet has a similar effect to that produced with antibiotic growth promoter.

Effect of dietary Saccharomyces-derived prebiotic refined functional carbohydrates as antibiotic alternative on growth performance and intestinal health of broiler chickens reared in a commercial farm

The search for effective in-feed antibiotic alternative is growing due to the global trend to reduce or ban the utilization of antibiotics as growth promotors in poultry diets. This study was processed to assess the effect of dietary refined functional carbohydrates (RFCs) replacing antibiotic growth promoters (AGP) on growth performance, intestinal morphologic structure and microbiota, as well as intestinal immune function and barrier function of broilers reared on a commercial broilers farm. Trials contained 3 treatments with 4 replicate broiler houses, with about 25,000 birds each room. The treatments were control group (CON), RFCs group (CON + 100 mg/kg RFCs), and AGP group (CON + 50 mg/kg bacitracin methylene disalicylate (BMD), respectively. Results showed that RFCs and AGP group significantly increased (P < 0.05) average daily gain (ADG) during d 22 to 45 in contrast to control. Compared with the control and AGP-treated groups, feeding RFCs increased (P < 0.05) jejunal villus height to crypt depth ratio. AGP addition reduced (P < 0.05) the jejunal villi surface area compared to broilers fed control and RFC supplemented diets. Supplementation of RFCs promoted (P < 0.05) the growth of Lactobacillus but inhibited Escherichia coli and Salmonella proliferation compared with the control group. Inclusion of RFCs and BMD enhanced (P < 0.05) antibody titers against avian influenza virus H9 compared with control. RFCs and AGP both down-regulated (P < 0.05) intestinal TLR4 mRNA levels, whereas RFCs tended to up-regulate (P = 0.05) IFN-γ gene expression compared to control. Expression of intestinal tight junction genes was not affected by either AGP or RFCs supplementation. Based on above observation, we suggested that RFCs could replace in-feed antibiotic BMD in broiler diets for reducing intestinal pathogenic bacteria and modulating immunity of broilers.

Yeast derivatives as a source of bioactive components in animal nutrition: A brief review

With a long history of inclusion within livestock feeding programs, yeast and their respective derivatives are well-understood from a nutritional perspective. Originally used as sources of highly digestible protein in young animal rations in order to offset the use of conventional protein sources such as soybean and fish meal, application strategies have expanded in recent years into non-nutritional uses for all animal categories. For the case of yeast derivatives, product streams coming from the downstream processing of nutritional yeast, the expansion in use cases across species groups has been driven by a greater understanding of the composition of each derivative along with deeper knowledge of mechanistic action of key functional components. From improving feed efficiency, to serving as alternatives to antibiotic growth promoters and supporting intestinal health and immunity while mitigating pathogen shedding, new use cases are driven by a recognition that yeast derivatives contain specific bioactive compounds that possess functional properties. This review will attempt to highlight key bioactive categories within industrially applicable yeast derivatives and provide context regarding identification and characterization and mechanisms of action related to efficacy within a range of experimental models.

Dietary supplementation with Cyberlindnera jadinii improved growth performance, serum biochemical Indices, antioxidant status, and intestinal health in growing raccoon dogs (Nyctereutes procyonoides)

This study was conducted to investigate whether different dietary Cyberlindnera jadinii levels affect growth performance, serum immunity, antioxidant capacity, and intestinal microbiota in growing raccoon dogs. Forty-five healthy male raccoon dogs were randomly assigned to three treatment groups, with 15 raccoon dogs per group. Each raccoon dog was housed in an individual cage. The raccoon dogs in the three groups were fed diets supplemented with Cyberlindnera jadinii at dosages of 0 (N group), 1 × 10⁹ (L group) and 5 × 10⁹ CFU/g (H group). A 7-day pretest period preceded a formal test period of 30 days. The results showed that Cyberlindnera jadinii in the L and H groups improved average daily gain (ADG) (P < 0.05) and decreased the ratio of feed to weight (F/G) (P < 0.05). Serum immunoglobulins A and G levels were increased in the L and H groups compared to the N group (P < 0.05). Cyberlindnera jadinii in the L and H groups increased serum superoxide dismutase activity (P < 0.05), and serum glutathione peroxidase activity was increased in the L group compared to the N group (P < 0.05). The relative abundance of Firmicutes and Actinobacteriota were increased, and the relative abundance of Bacteroidota was decreased in the L and H groups compared to the N group (P < 0.05). The relative abundance of Proteobacteria and Cyanobacteria was increased in the H group compared to the other two groups (P < 0.05). The ratio of Firmicutes to Bacteroidetes in the Cyberlindnera jadinii supplementation groups increased compared with the N group (P < 0.05). The relative abundance of Megasphaera and Bifidobacterium were increased, and the relative abundance of Prevotella was decreased in the L and H groups compared to the N group (P < 0.05). The relative abundance of Dialister was increased, while the relative abundance of Blautia was decreased in the H group compared to the other two groups (P < 0.05). The relative abundance of Agathobacter was decreased in the H group compared to the N group (P < 0.05). In conclusion, dietary supplementation with Cyberlindnera jadinii increased growth performance, serum immunity, antioxidant capacity, and improved intestinal microbiota in growing raccoon dogs. Cyberlindnera jadinii can therefore be used as a growth promoter in raccoon dogs.

Yeast cell wall upregulated cell-mediated immune responses to Newcastle disease virus vaccine

A recent study has suggested that yeast cell wall product (YP) enhanced serum hemagglutination inhibition (HI) titers and intestinal sIgA responses in chickens immunized with Newcastle disease virus (NDV) vaccine. In the present study, the cell-mediated immune responses elicited by NDV and YP were investigated in commercial broilers. Broilers were fed 0 or 0.1% YP and immunized with a live NDV vaccine via an intraocular-and-intranasal route at 14 and 28 days old. After that, blood samples were collected for determination of HI titer, cytokine content, and blood analysis. Eight chickens were randomly selected from each group and sacrificed. Lymphocytes were harvested from the spleens for lymphocyte proliferation and flow cytometry analysis. Total RNA was extracted from spleen and jejunum for RT-qPCR analysis. The results showed that YP significantly increased serum concentration of IL-4, IL-6, IFN-γ, TNF-β, as well as promoted lymphocytes proliferation in broilers immunized with NDV vaccine. The enhanced cell-mediated immunity is correlated with the upregulated mRNA expression of TGF-β, IL-6, TLR5, GATA-3, and T-bet in the spleen and upregulated mRNA expression of CCR-9, J-chain, pIgR, and TLR3 in the jejunum of chickens. It is noteworthy that no significant side effect was observed after the administration of YP. Therefore, YP could be safely used as potential immunopotentiator assisting NDV vaccine for chickens.

Effects of a yeast-derived product on growth performance, antioxidant capacity, and immune function of broilers

Yeast culture plus enzymatically hydrolyzed yeast cell wall (YC-EHY) contains crude protein, mannan-oligosaccharide, β-glucan and yeast culture. This study was carried out to explore the effects of dietary YC-EHY at different levels on growth performance, antioxidant capacity, and immune function of broiler chickens. A total of 320 one-day-age male broiler chicks were allocated into 4 groups and were fed with a basal diet supplemented with 0 mg/kg (the control group), 50 mg/kg, 100 mg/kg, 150 mg/kg YC-EHY for 42 d. Dietary YC-EHY improved average daily gain and feed efficiency during the starter, grower, and overall periods as well as average body weight of broiler chickens on 42 d (linear and quadratic, P < 0.05). Broiler chickens fed with YC-EHY quadratically increased jejunal sucrase activity on 21 d (quadratic, P < 0.05), and linearly and quadratically enhanced maltase activity on 21 and 42 d (linear and quadratic, P < 0.05). Supplementing YC-EHY linearly and quadratically enhanced jejunal superoxide dismutase (SOD) activity on 21 and 42 d and glutathione peroxidase (GPX) activity on 42 d whereas decreased malonaldehyde (MDA) concentration on 42 d (linear and quadratic, P < 0.05). Consistently, the jejunal genes expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and SOD1 on 21 and 42 d, heme oxygenase-1 (HO-1) and GPX1 on 42 d were enhanced by YC-EHY supplementation (linear and quadratic, P < 0.05). The concentrations of jejunal immunoglobulin G (IgG) on 21 and 42 d and secreted immunoglobulin A (SIgA) on 42 d were linearly and quadratically elevated by supplementing YC-EHY (linear and quadratic, P < 0.05). Dietary YC-EHY quadratically increased jejunal IgG and IgM genes expression on 21 d (quadratic, P < 0.05), and linearly and quadratically enhanced the genes expression of IgG and IgM on 42 d (linear and quadratic, P < 0.05). Overall, this study indicated that supplementing YC-EHY could exert beneficial effects on growth performance, intestinal antioxidant capacity and immune function in broiler chickens.

Effects of different concentration of organic and inorganic trace minerals (zinc, selenium, and chromium) supplementation on expression of chTLR4 gene and humoral immune response in broilers

BACKGROUND AND AIM

Poultry production is the fastest-growing livestock sector in developing countries. In the poultry diet, trace minerals (zinc [Zn], selenium [Se], and chromium [Cr]) are normally administered in the inorganic form which has been traditionally considered as the most cost-effective and easily available but organic forms of these trace minerals have a higher bioavailability, lower dietary inclusion and cause less environmental pollution as compared to inorganic form. This study aimed to investigate the effect of different concentrations of organic and inorganic forms of trace minerals (Zn, Se, and Cr) supplementation (0-35 days) on expression of chTLR4gene and humoral immune response in broilers.

MATERIALS AND METHODS

A total of 216 broilers were randomly divided into 12 groups and each group divided into three replicates consisting of six broilers each. T1 (R1, R2, and R3) group was kept as control. T2, T3, and T4 (R1, R2, and R3) groups were supplemented with inorganic form of Zn at 40 mg/kg of feed, organic form of Zn at 40 mg/kg of feed, and 50% organic form of Zn at 20 mg/kg of feed, respectively. T5, T6, and T7 (R1, R2, and R3) groups were supplemented with inorganic form of Se at 0.3 mg/kg of feed, organic form of Se at 0.3 mg/kg of feed, and 50% organic form of Se at 0.15 mg/kg of feed, respectively. T8, T9, and T10 (R1, R2, and R3) groups were supplemented with inorganic form of Cr at 2 mg/kg of feed, organic form of Cr at 2 mg/kg of feed, and 50% organic form of Cr at 1 mg/kg of feed, respectively. T11 and T12 (R1, R2, and R3) groups were supplemented with a combination of all three minerals from inorganic and organic forms, respectively.

RESULTS

Reverse transcriptase-polymerase chain reaction gene expression analysis revealed that in bursa of Fabricius, maximum upregulation of chTLR4 (3.0214 fold) was observed in T6 group, and in spleen, maximum upregulation of chTLR4 (3.2140 fold) was observed in T3 group as compared to control group. On day 35, the maximum plasma immunoglobulin G concentration was observed in organic trace minerals (OTMs) supplemented, whereas the minimum concentration was recorded in control group. On day 28 and 35, the overall mean heterophil:lymphocyte ratio showed a significant difference (p<0.05) between control and OTM supplemented groups. A significantly higher immune organ weight (spleen and bursa of Fabricius) was recorded in OTM supplemented group as compared to control and other supplemented group.

CONCLUSION

Supplementation of organic form of Zn, Se, and Cr either alone or in combination increase humoral immune response and upregulation of chTLR4 gene expression in bursa and spleen indicates a beneficial effect of OTM in augmentation of immune system in broilers.

Dietary fiber in poultry nutrition and their effects on nutrient utilization, performance, gut health, and on the environment: a review

Dietary fiber (DF) was considered an antinutritional factor due to its adverse effects on feed intake and nutrient digestibility. However, with increasing evidence, scientists have found that DF has enormous impacts on the gastrointestinal tract (GIT) development, digestive physiology, including nutrient digestion, fermentation, and absorption processes of poultry. It may help maintain the small and large intestine's integrity by strengthening mucosal structure and functions and increasing the population and diversity of commensal bacteria in the GIT. Increasing DF content benefits digestive physiology by stimulating GIT development and enzyme production. And the inclusion of fiber at a moderate level in diets also alters poultry growth performance. It improves gut health by modulating beneficial microbiota in the large intestine and enhancing immune functions. However, determining the source, type, form, and level of DF inclusion is of utmost importance to achieve the above-noted benefits. This paper critically reviews the available information on dietary fibers used in poultry and their effects on nutrient utilization, GIT development, gut health, and poultry performance. Understanding these functions will help develop nutrition programs using proper DF at an appropriate inclusion level that will ultimately lead to enhanced DF utilization, overall health, and improved poultry growth performance. Thus, this review will help researchers and industry identify the sources, type, form, and amount of DF to be used in poultry nutrition for healthy, cost-effective, and eco-friendly poultry production.

TLR-Mediated Cytokine Gene Expression in Chicken Peripheral Blood Mononuclear Cells as a Measure to Characterize Immunobiotics

Immunobiotics are probiotics that promote intestinal health by modulating immune responses. Immunobiotics are recognized by Toll-like receptors (TLRs) and activate cytokine gene expression. This study aimed to characterize cytokine gene expression in the chicken peripheral blood mononuclear cells (PBMC) stimulated with purified TLR ligands and live probiotics. PBMC were isolated from the whole blood. PBMC were stimulated with: lipopolysaccharide (LPS), CpG ODN, Pam3CSK4, Zymosan, galactooligosaccharides (GOS), Lactococcuslactis subsp. cremoris (L. lactis), and Saccharomyces cerevisiae at 42.5 °C and 5% CO₂ for 3 h, 6 h, and 9 h. After each time-point, PBMC were harvested for RNA isolation. Relative gene expression was analyzed with RT-qPCR for cytokine genes (IL-1β, IL-2, IL-3, IL-4, IL-6, IL-8, IL-10, IL-12p40, and IFN-ɣ) and reference genes (ACTB and G6PDH). Genes were clustered into pro-inflammatory genes, Th1/Th2 genes, and Th1-regulators. The gene expression differed between treatments in IL1-β, IL-6, IL-8, IL-10, and IL-12p40 (p < 0.001). The genes IL-1β, IL-6, and IL-8 had the highest fold change of mRNA expression at 3 h in response to TLR ligands. L. lactis up-regulated the pro-inflammatory genes at the 6 h time-point. L. lactis did not activate the anti-inflammatory IL-10 gene, but activated IL-12p40 at 6 h. Hereby, L. lactis was proven to exert immunostimulatory properties in PBMC.

Structure, preparation, modification, and bioactivities of β-glucan and mannan from yeast cell wall: A review

In order to solve the antibiotic resistance, the research on antibiotic substitutes has received an extensive attention. Many studies have shown that β-glucan and mannan from yeast cell wall have the potential to replace antibiotics for the prevention and treatment of animal diseases, thereby reducing the development and spread of antibiotic-resistant bacterial pathogens. β-Glucan and mannan had a variety of biological functions, including improving the intestinal environment, stimulating innate and acquired immunity, adsorbing mycotoxins, enhancing antioxidant capacity, and so on. The biological activities of β-glucan and mannan can be improved by chemically modifying its primary structure or reducing molecular weight. In this paper, the structure, preparation, modification, and biological activities of β-glucan and mannan were reviewed, which provided future perspectives of β-glucan and mannan.

Cyberlindnera jadinii Yeast as a Protein Source for Weaned Piglets-Impact on Immune Response and Gut Microbiota

Supplying novel feed ingredients for pig production is crucial to enhance food security and decrease the environmental impact of meat production. Several studies have focused on evaluating the beneficial health effects of yeast in pigs. However, its use as a protein source has been partially addressed. Previously, we have shown that yeast at high inclusion levels maintains growth performance and digestibility, while nutrient digestibility, intestinal villi height and fecal consistency were improved. The present study combined microbiome, short-chain fatty acid, and immune parameter analysis to investigate the effect of high inclusion of yeast in diets for post-weaning piglets. Our results showed that yeast did not have a significant impact on the hematological or biochemical parameters in blood. The different immune cell subpopulations isolated from blood and distal jejunal lymph nodes (DJLN) were analyzed by flow cytometry and showed that yeast diet induced an increased number of the subtype of leukocytes CD45+/CD3-/CD8+, a special type of Natural Killer (NK) cells. Also, a very mild to moderate infiltration of neutrophilic granulocytes and lower IgA level were observed in the colon of yeast fed piglets. The microbiome profiling in different compartments of the gastrointestinal tract of piglets was performed using 16S rRNA metabarcoding. The results showed that 40% replacement of dietary protein had a statistically significant effect on the microbial communities in cecum and colon, while the microbial population in ileum and jejunum were not affected. Analysis of predicted microbial metabolic pathways analysis revealed significant upregulation of short-chain fatty acids, ether lipid metabolisms, secondary bile acids, and several other important biosynthesis pathways in cecum and colon of pigs fed yeast. In conclusion, the results showed that diet containing 40% of yeast protein positively shaped microbial community in the large intestine and increased the number of a specific subpopulation of NK cells in the DJLN. These results showed that yeast modulates the microbiome and decreases the secretion of IgA in the colon of post-weaning pigs.

The effects of feeding yeast bioactives to broiler breeders and/or their offspring on growth performance, gut development, and immune function in broiler chickens challenged with Eimeria

Yeast bioactives (YB) may stimulate broiler breeders (BB) to increase deposition of immunoglobulins (Ig) in eggs. We investigated the effects of feeding YB (mixture of derivatives from whole yeast subjected to enzymatic hydrolysis) to BB and/or their offspring on growth performance, gut development, and immune function in broiler chickens challenged with Eimeria. The BB (Ross 708 ♀ and Ross ♂) were assigned to 2 groups (60 ♀ and 10 ♂) and fed basal or basal diet supplemented with 500 g of YB/Mt. A total of 250 fertile eggs per treatment were collected, incubated, hatched, and sexed. Additional egg samples were analyzed for IgA and IgY contents. A total of 160 broiler chicks (80 ♀ and 80 ♂) from each breeder experimental group were placed in cages based on sex and BW resulting in 32 cages for each BB treatment group. Cages (16 per BB treatment group) were allocated to basal broiler chick diet or basal diet supplemented with 500 g of YB/Mt. On day 9, half of each BB by broiler chick dietary treatments was challenged with 1 mL of Eimeria culture (100,000 oocysts of Eimeria acervulina and 25,000 oocysts of Eimeria maxima). On day 14, all birds were necropsied for intestinal lesion scores and samples. Feeding YB to BB increased (P < 0.05) IgA concentration in egg yolk. Eimeria challenge decreased (P < 0.05) pancreas weight, jejunal villus height (VH), and growth performance but increased spleen weight, intestinal mass and jejunal mucosa IgA concentration. Independent of Eimeria challenge, feeding YB to BB and/or to chicks resulted in higher (P < 0.001) jejunal VH compared with feeding it to BB only or not at all. In conclusion, Eimeria challenge reduced growth performance and had negative effects on indices of intestinal function and health. Feeding YB to BB increased deposition of IgA in hatching eggs and improved jejunal VH independent of Eimeria challenge when fed to BB and/or to broiler chicks.

Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens

Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over Eimeria species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of Eimeria. There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in Eimeria challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral Eimeria vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.

Nucleotide-rich yeast extract fed to broiler chickens challenged with Eimeria: impact on growth performance, jejunal histomorphology, immune system, and apparent retention of dietary components and caloric efficiency1

Nucleotide-rich yeast extract (YN) was investigated for its effects on growth performance, jejunal histomorphology and mucosal immunoglobulin A (IgA), immune organs weight and apparent retention (AR) of components in broiler chickens challenged with Eimeria. A total of 336 day-old male chicks (Ross x Ross 708) were placed in floor pens and provided a corn-soybean meal-based diet without or with YN (500 g/mt) (n = 14). On day 10, 7 replicates per diet were orally administered with 1 mL of sporulated E. acervulina and E. maxima oocysts and the rest (non-challenged control) administered equivalent distilled water creating a 2 × 2 factorial arrangement for the post-challenge period (day 11 to 35). Feed intake (FI), BWG, and FCR responses were measured in pre- and post-challenge periods. Excreta samples were collected on day 14 to 17 and 31 to 34 for oocyst count and AR of components, respectively. On day 15 and 35, 5 birds/pen were necropsied for intestinal samples. Spleen, bursa, and thymus weights were also recorded at both time points and breast yield on day 35. Diet had no effect (P > 0.05) on pre-challenge growth performance. Interaction (P = 0.046) between Eimeria and YN on FI was such that Eimeria challenge increased FI (day 11 to 35) in non-YN birds. There was no interaction (P > 0.05) between Eimeria and YN on other post-challenge responses. Eimeria reduced (P < 0.05) BWG, FCR, caloric efficiency, day 15 jejunal villi height and IgA concentration, and increased (P < 0.01) day 15 spleen weight. On day 35, YN increased bursa weight (1.57 vs. 1.78 mg/g BW, P = 0.04). There was a tendency for an interaction effect (P = 0.09) on day 35 thymus weight, such that in challenged birds, YN fed birds tended to have a lighter thymus relative to non-YN fed birds. In conclusions, independent of Eimeria challenge, supplemental YN had no effect on growth performance, caloric efficiency, and intestinal function but increased immune organ weights.

Effects of dietary yeast beta-1,3-1,6-glucan on growth performance, intestinal morphology and chosen immunity parameters changes in Haidong chicks

Objective

This study investigated the effects of 1,3-1,6 beta-glucan added to the diet of Haidong chicks reared under hypoxic conditions, to ascertain the growth performances, immunity and intestinal morphology changes.

Methods

A total of 750 chicks were divided into five groups and fed diets containing 0.5g/kg, 1.0g/kg and 2.0g/kg 1,3-1,6 beta-glucan from yeast (G1, G2, G3, respectively), 0.2g/kg Taylor rhizomorph (T) and a control feed (C).

Results

The body weight and body weight gain was higher in chicks fed 1,3-1,6 beta-glucan and Taylor rhizomorph than in control group. Feed conversion ratio significantly differed for G2 and G3 groups in comparison to control group. The relative weight of bursa was higher in G1, G2 and G3 groups. The white blood cells and lymphocytes were significantly increased in groups fed 1,3-1,6 beta-glucan. The IgG of serum peak appeared in the G3 group. The villous height of the duodenum was higher in 1,3-1,6 beta-glucan feed groups. In the jejunum, the villous height was higher in G2 and G3 groups and crypt depth for all the groups fed β-glucan;. At ileum level the villous height and crept depth was higher for groups G1, G2 and G3.

Conclusion

The growth performance of Haidong chicks is improved when 10 and 20 g/kg 1,3-1,6 beta-glucan is included in the diet; hence, it is suggested to diet include 1,3-1,6 beta-glucan in poultry diet to reduce and replace the use of antibiotics.

Heterologous expression and characterization of Penicillium citrinum nuclease P1 in Aspergillus niger and its application in the production of nucleotides

Nuclease P1 gene (nuc P1) which was cloned from Penicillium citrinum and expressed in A. niger Bdel4 with the low-background extracellular protein. The expression strategy of multi-copy nuc P1 in the A. niger with the linker of 2A peptide was applied to improve the enzyme activity of nuclease P1, the highest activity up to 77.6 U/mL. After Ni-chelate purification, the specific enzyme activity, the optimum temperature and pH were 32.4 U/mg, 65 °C and 5.3 respectively. The recombination nuclease P1 was activated by addition of Mg²⁺, Zn²⁺ and Cu²⁺, and inhibited by addition of Ca²⁺, Fe²⁺, Mn²⁺, Ni²⁺, Co²⁺, Mg²⁺, K⁺ and EDTA. Furthermore, the enzyme hydrolyses yeast RNA efficiently into 5'- nucleotides. Through enzymolysis, the highest concentration of nucleotides achieved 15.12 mg/mL, and 75U nuclease P1 is suitable amount should be added to the enzymolysis system.

Corn dried distillers grains with solubles (cDDGS) in the diet of pigs change the expression of adipose genes that are potential therapeutic targets in metabolic and cardiovascular diseases

Background

Corn dried distillers grains with solubles (cDDGS) are a byproduct of biofuel and alcohol production. cDDGS have been used in pig feed for many years, because they are readily available and rich in protein, fiber, unsaturated fatty acids and phytosterols. However, feed mixtures too high in cDDGS result in the worsening of backfat quality. We performed RNA-sequencing analysis of backfat from crossbred pigs fed different diets. The diets were isoenergetic but contained different amounts of cDDGS and various sources of fats. The animals were divided into four dietary groups during the two months of experimentation: group I (control (-cDDGS+rapeseed oil)), group II (+cDDGS+rapeseed oil), group III (+cDDGS+beef tallow), and group IV (+cDDGS+coconut oil). The aim of the present experiment was to evaluate changes in the backfat transcriptome of pigs fed isoenergetic diets that differed in cDDGS presence.

Results

Via DESeq2 software, we identified 93 differentially expressed genes (DEGs) between groups I and II, 13 between groups I and III, and 125 between groups I and IV. DEGs identified between group I (-cDDGS+rapeseed oil) and group II (+cDDGS+rapeseed oil) were highly overrepresented in several KEGG pathways: metabolic pathways (FDR < 1.21e-06), oxidative phosphorylation (FDR < 0.00189), fatty acid biosynthesis (FDR < 0.00577), Huntington’s disease (FDR < 0.00577), fatty acid metabolism (FDR < 0.0112), Parkinson’s disease (FDR < 0.0151), non-alcoholic fatty liver disease (NAFLD) (FDR < 0.016), Alzheimer’s disease (FDR < 0.0211) and complement and coagulation cascades (FDR < 0.02).

Conclusions

We observed that the addition of cDDGS positively affects the expression of several genes that have been recently proposed as potential targets for the treatment of obesity, diabetes, cardiovascular disease, and Alzheimer’s disease (e.g., FASN, AACS, ALAS1, HMGCS1, and VSIG4). Thus, our results support the idea of including cDDGS into the diets of companion animals and humans and encourage research into the bioactive ingredients of cDDGS.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5265-x) contains supplementary material, which is available to authorized users.

Effects of dietary yeast nucleotides supplementation on intestinal barrier function, intestinal microbiota, and humoral immunity in specific pathogen-free chickens

Yeast nucleotides are a fine functional additive in human and animals. The effects of dietary yeast nucleotides supplementation on intestinal development, expression of intestinal barrier-related genes, intestinal microbiota, and infectious bronchitis virus (IBV) antibody titer of specific pathogen-free (SPF) chickens were investigated. A total of 60 1-d-old chickens were divided into 4 groups, each of which included 3 replicates of 5 chickens. Group 1 served as a control that was fed a basal diet. Groups 2 to 4 were fed the basal diet supplemented with 0.1%, 0.3% and 0.5% yeast nucleotides, respectively. All chickens were inoculated intranasally with inactivated IBV vaccine at day 1 and day 10. At day 17, the intestinal development, expression of intestinal barrier-related genes and microbiota were evaluated. There was a significant increased ileal villus height and villus height to crypt depth ratio in group 2 (P < 0.05). Moreover, group 4 exhibited higher expression of zonula occludens-1 (ZO-1) and Occludin gene in ileum (P < 0.05), whereas groups 2 and 3 exhibited higher expression of Mucin 2 (MUC2) and trefoil factor 2 (TFF2) gene (P < 0.05), group 2 showed lower expression of IFN-α gene (P < 0.05). Dietary yeast nucleotides increased intestinal bacterial diversity (P < 0.05), and the abundance of Lactobacillus (P < 0.05). At day 10, 17, 24, 31, 38, and 45, the serum IBV antibody titers were tested. Group 2 exhibited higher IBV antibody titer at day 17 (P < 0.05), furthermore, groups 2 to 4 reached the effective levels 1 wk earlier than control group. In conclusion, dietary yeast nucleotides supplementation can help birds to mount a faster and stronger antibody response to IBV vaccine. In addition, dietary yeast nucleotides supplementation can also promote the intestinal development and barrier-related genes expression, and diversity and richness of intestinal microbiota.

Eubiotics for Food Security at Farm Level: Yeast Cell Wall Products and Their Antimicrobial Potential Against Pathogenic Bacteria

The population increase in the last century was the first cause of the industrialization of animal productions, together with the necessity to satisfy the high food demand and the lack of space and land for the husbandry practices. As a consequence, the farmers moved from extensive to intensive agricultural systems and introduced new practices, such as the administration of antimicrobial drugs. Antibiotics were then used as growth promoters and for disease prevention. The uncontrolled and continuous use of antibiotics contributed to the spread of antibiotic resistance in animals, and this had adverse impacts on human health. This emergence led the European Union, in 2003, to ban the marketing and use of antibiotics as growth promoters, and for prophylaxis purposes from January 2006. This ban caused problems in farms, due to the decrease in animal performances (weight gain, feed conversion ratio, reproduction, etc.), and the rise in the incidence of certain diseases, such as those induced by Clostridium perfringens, Salmonella, Escherichia coli, and Listeria monocytogenes. The economic losses due to the ban increased the interest in researching alternative strategies for the prophylaxis of infectious diseases and for health and growth promotion, such as feed additives. Yeast-based materials, such as cell wall extract, represent promising alternatives to antibiotics, on the base of their prebiotic activity and their claimed capacity to bind enteropathogenic bacteria. Several authors reported examples of the effectiveness of yeast cell wall products in adsorbing bacteria, but there is a lack of knowledge on the mechanisms involved in this interaction. The purpose of this review is to provide an overview of the current approaches used for the control of pathogenic bacteria in feed, with a particular focus on the use of yeast-derived materials proposed to control zoonoses at farm level, and on their effect on animal health.

Dietary L-theanine alleviated lipopolysaccharide-induced immunological stress in yellow-feathered broilers

L-theanine, a natural nonprotein amino acid with a high biological activity, is reported to exert anti-stress properties. An experiment with a 3 × 2 factorial arrangement was conducted to investigate the effects of dietary L-theanine on growth performance and immune function in lipopolysaccharide (LPS)-challenged broilers. A total of 432 one-day-old male yellow-feathered broilers were randomly assigned to 3 dietary treatments (control, antibiotic and L-theanine diets) with 2 subgroups of each (6 replicate cages; 12 birds/cage). Birds from each subgroup of the 3 dietary treatments were intra-abdominally injected with the same amount of LPS or saline at 24, 25, 26 d of age. Both dietary L-theanine and antibiotic improved (P < 0.05) the growth performance of birds before LPS injection (d 1 to 21). The effect of dietary L-theanine was better (P < 0.05) than that of antibiotic. Lipopolysaccharide decreased feed intake (FI) and body weight gain (BWG) from d 22 to 28 (P < 0.05), BWG and feed to gain ratio (F:G) from d 29 to 56 (P < 0.05), increased mortality in different growth periods (P < 0.05), elevated the levels of serum cortisol, α1-acid glycoprotein (α1-AGP), interleukin-6 (IL-6) on d 24 and 25 (P < 0.05), reduced immune organ indexes and contents of jejunal mucosal secretory immunoglobulin A (sIgA) on d 28 (P < 0.05). The decreased FI and BWG, as well as increased F:G and mortality in LPS-challenged birds, were alleviated by dietary L-theanine or antibiotic from d 29 to 56 and from d 1 to 56. Dietary L-theanine mitigated the elevated serum α1-AGP level on d 25, serum IL-6 concentration on d 24 and 26, and the decreased jejunal mucosal sIgA content on d 28 of the LPS-challenged birds. The results indicated that L-theanine had potential to alleviate LPS-induced immune stress in broilers.