Yeast cell wall polysaccharides accelerate yet in-feed antibiotic delays intestinal development and maturation via modulating gut microbiome in chickens

BACKGROUND

It is important to promote intestinal development and maturation of chicks for feed digestion and utilization, intestinal health, and disease resistance. This study aimed to investigate the effects of dietary yeast cell wall polysaccharides (YCWP) addition on intestinal development and maturation of chickens and its potential action mechanism.

METHODS

180 one-day-old male Arbor Acres broilers were randomly assigned to three groups containing control (basal diets without any antibiotics or anticoccidial drug), bacitracin methylene disalicylate (BMD)-treated group (50 mg/kg) and YCWP-supplemented group (100 mg/kg).

RESULTS

Compared with control group, in-feed antibiotic BMD continuous administration significantly decreased crypt depth (d 21) and villus height (d 42) along with mucosal maltase activity (d 42) in the ileum (P < 0.05). Also, BMD markedly downregulated gene expression levels of β-catenin, lysozyme, occludin and FABP-2 (d 21) and innate immune related genes CD83 and MHC-I mRNA levels (d 42, P < 0.05), and decreased goblet cell counts in the ileum of chickens (d 21 and d 42, P < 0.05). While, TLR-2, TLR-6 and iNOS mRNA abundances were notably upregulated by BMD treatment (d 42, P < 0.05). Nevertheless, dietary YCWP addition significantly increased the ratio of villus height to crypt depth (d 21), villus surface area (d 21 and d 42), ileal alkaline phosphatase and maltase activities as well as goblet cell (d 21 and d 42) and IgA-producing plasma cell numbers as compared to BMD treatment (d 21, P < 0.05). YCWP addition also upregulated gene expression levels of Lgr5, Wnt/β-catenin signaling pathway related gene (Wnt3, β-catenin, d 21; β-catenin, d 42), intestinal cells proliferation marker Ki-67 and barrier function related genes (occludin, d 21 and d 42, P < 0.05). Moreover, YCWP significantly increased antigen presenting cell marker related genes (MHC-II, d 21; CD83 and MHC-I, d 42), TLR-1, TLR-2 and TLR-6 mRNA levels (d 21, P < 0.05). Cecal microbiome analysis showed that YCWP addition obviously improved cecal microbial composition, as indicated by increasing relative abundance of Fournierella, Psychrobacter and Ruminiclostridium on d 21, and Alistipes and Lactobacillus on d 42, which were positively related with gut development and maturation related indexes (P < 0.05).

CONCLUSION

Collectively, YCWP promoted yet antibiotic BMD delayed intestinal morphological and immunological development linked with modulating gut microbiome in chickens.

Effects of Lactiplantibacillus plantarum and Galactooligosaccharide Administered In Ovo on Hatchability, Chick Quality, Performance, Caecal Histomorphology and Meat Quality Traits of Broiler Chickens

The presented study explored the promising alternatives of in ovo injection with Lactiplantibacillus plantarum (LP) and galactooligosaccharide (GOS) in the poultry industry. The study aimed to assess the effects of probiotic and prebiotic on various aspects of poultry production. The study involved 300 Ross broiler eggs, individually candled on Day 7 of embryonic development. The eggs were sorted into four groups: negative control (no injection), positive control (0.9% physiological saline injection), GOS 3.5 mg/egg and LP 1 × 106 CFU/egg. The groups used during the incubation period were the same for the animal trial; each pen/group had 25 chickens. At the end of the experiment, 8 chickens from each group were slaughtered for tissue sample collection and 12 chickens were slaughtered to determine slaughter yield, carcass and meat quality. All data were analysed by one-way ANOVA or repeated measured ANOVA except for the parameters that did not meet the assumption of normality, the Kruskal-Wallis test (Dunn's test) was used. Key findings revealed that hatchability remained unaffected across groups, indicating the safety of the in ovo injections. Both LP and GOS enhanced chick quality, as evidenced by improved body weight, Pasgar score and chick length. The in ovo administration of LP increased the body weight of the chickens during the first-week post-hatch (7 days of age) without impacting feed intake and feed conversion ratio in the later stages. The study demonstrated no adverse effects on meat quality due to the in ovo injection of LP and GOS. Additionally, a positive impact on caecal histomorphology was observed and early gut colonization of beneficial bacteria (Lactobacillus spp. and Bifidobacteria spp.) indicated potential benefits for intestinal health in broilers. In conclusion, the in ovo inoculation of 1 × 106 LP and 3.5 mg of GOS per egg increased the relative abundance of Lactobacillus spp. and Bifidobacterium spp. and showcased promising enhancements in chick quality without compromising growth performance, meat quality and caecal histomorphology. These findings suggest a positive outlook for these substances as a viable alternative for improving poultry health and productivity.

Responses of Intestinal Antioxidant Capacity, Morphology, Barrier Function, Immunity, and Microbial Diversity to Chlorogenic Acid in Late-Peak Laying Hens

This study examined the influence of chlorogenic acid (CGA) on gut antioxidant status, morphology, barrier function, immunity, and cecal microbiota in late-peak laying hens. A total of 240 Hy-Line Brown hens, aged 43 weeks, were randomly assigned to four groups, the basal diet +0, 400, 600, and 800 mg/kg CGA, for 12 weeks. The results revealed that CGA significantly reduced ileal H2O2 and malondialdehyde levels; increased duodenal height, ileal villus height, and villus height-to-crypt depth ratio; while decreasing jejunal crypt depth. The 600 and 800 mg/kg CGA significantly upregulated the duodenal, jejunal, and ileal ZO-1 and occludin gene expression; increased IgG levels in serum and ileum; and upregulated ileal IgA gene expression. The 600 mg/kg CGA significantly upregulated CD3D and CD4 gene expression, while downregulating IL-1β gene expression in duodenum, jejunum, and ileum. Moreover, CGA changed the gut microbiota structure. The SCFA-producing bacteria unclassified_f__Peptostreptococcaceae, unclassified_f_Oscillospiraceae, Pseudoflavonifractor, Lachnospiraceae_FCS020_group, Oscillospira, Elusimicrobium, Eubacterium_ventriosum_group, Intestinimonas, and norank_f_Coriobacteriales_Incertae_Sedis were significantly enriched in the 400, 600, and/or 800 mg/kg CGA groups. The bacteria Lactobacillus, Bacillus, and Akkermansia were significantly enriched in the 600 mg/kg CGA group. Conclusively, dietary CGA (600-800 mg/kg) improved intestinal antioxidant status, morphology, barrier and immune function, and beneficial microbiota growth in late-peak laying hens.

A Meta-Analysis of the Effects of Dietary Yeast Mannan-Rich Fraction on Broiler Performance and the Implication for Greenhouse Gas Emissions from Chicken Production

Dietary supplementation of yeast-derived mannan-rich fraction (MRF) could improve the gastrointestinal health and production efficiency of broilers, and, consequently, lower the environmental impacts of chicken production. The objective of this meta-analysis was to quantify the retrospective effects of feeding MRF (Actigen®, Alltech Inc., Nicholasville, KY) on the production performance of broilers. The meta-analysis database included 27 studies and consisted of 66 comparisons of MRF-supplemented diets vs. basal (i.e., negative control) and antibiotic-supplemented (i.e., positive control) diets. A total of 34,596 broilers were involved in the comparisons and the average final age of the birds was 35 days. Additionally, the impact of feeding MRF on the carbon footprint (feed and total emission intensities) of chicken production was evaluated using the meta-analysis results of broiler performance (MRF vs. basal diets) to develop a scenario simulation that was analyzed by a life cycle assessment (LCA) model. A database of all trials (MRF vs. basal and antibiotic diets) indicated that feeding MRF increased (p < 0.01) average daily feed intake (ADFI; +3.7%), final body weight (FBW; +3.5%), and average daily gain (ADG; 4.1%) and improved (p < 0.01) feed conversion ratio (FCR; -1.7%) without affecting (p > 0.05) mortality. A subdatabase of MRF vs. basal diets indicated that dietary MRF increased ADFI (+4.5%), FBW (+4.7%), and ADG (+6.3%) and improved FCR (-2.2%) and mortality (-21.1%). For the subdatabase of MRF vs. antibiotic diets, both treatments exhibited equivalent effects (p > 0.05) on broiler performance parameters, suggesting that MRF could be an effective alternative to in-feed antibiotics. Subgroup analysis revealed that different study factors (year of study, breed/strain, production challenges, and MRF feeding duration) influenced the effect of dietary MRF on broiler performance. Simulated life cycle analysis (LCA) indicated that feeding MRF decreased feed and total emission intensities, on average, by -2.4% and -2.1%, respectively. In conclusion, these results demonstrate that dietary MRF is an effective nutritional solution for improving broiler performance, an effective alternative to in-feed antibiotic growth promoters, and reduces the environmental impact of poultry meat production.

Dietary supplementation with Dendrobium officinale leaves improves growth, antioxidant status, immune function, and gut health in broilers

Background

The Dendrobium officinale leaves (DOL) is an underutilized by-product with a large biomass, which have been shown to exhibit immunomodulatory and antioxidant functions. The purpose of this research was to investigate the effects of DOL on broiler growth performance, antioxidant status, immune function, and gut health.

Methods

One hundred and ninety-two 1-day-old chicks were selected and divided into 4 groups at random, 6 replicates for each group and 8 in each. Chicks were given a basal diet supplemented with different amounts of DOL: 0% (control group, NC), 1% (LD), 5% (MD), or 10% (HD). During the feeding trial (70 days), broiler body weight, feed intake, and residual feeding were recorded. On d 70, 12 broilers from each group were sampled for serum antioxidant and immune indexes measurement, intestinal morphological analysis, as well as 16S rRNA sequencing of cecal contents and short-chain fatty acid (SCFA) determination.

Results

In comparison to the NC group, the LD group had greater final body weight and average daily gain, and a lower feed conversion ratio (p < 0.05, d 1 to 70). However, in MD group, no significant change of growth performance occurred (p > 0.05). Furthermore, DOL supplementation significantly improved the levels of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase, but reduced the level of malondialdehyde (p < 0.05). Higher serum immunoglobulin A (IgA) content and lower cytokine interleukin-2 (IL-2) and IL-6 contents were observed in DOL-fed broilers than in control chickens (p <0.05). Compared to the NC group, duodenal villus height (VH) and villus height-to-crypt depth (VH:CD) ratio were considerably higher in three DOL supplementation groups (p < 0.05). Further, 16S rRNA sequencing analysis revealed that DOL increased the diversity and the relative abundance of cecal bacteria, particularly helpful microbes like Faecalibacterium, Lactobacillus, and Oscillospira, which improved the production of SCFA in cecal content. According to Spearman correlation analysis, the increased butyric acid and acetic acid concentrations were positively related to serum antioxidant enzyme activities (T-AOC and GSH-Px) and immunoglobulin M (IgM) level (p < 0.05).

Conclusion

Overall, the current study demonstrated that supplementing the dies with DOL in appropriate doses could enhance growth performance, antioxidant capacity, and immune response, as well as gut health by promoting intestinal integrity and modulating the cecal microbiota in broilers. Our research may serve as a preliminary foundation for the future development and application of DOL as feed additive in broiler chicken diets.

The Role of Dietary Supplementation of Yeast Cell Walls in Response to a Campylobacter jejuni Inoculation in Broiler Chickens

Controlling Campylobacter jejuni during broiler production is a topic of interest from a public health standpoint, as colonized birds can contaminate poultry products during processing and sicken humans if not properly cooked or handled before consumption. The aim of this study was to evaluate dietary yeast cell wall (YCW) as a potential alternative to antibiotic growth promoters with or without a C. jejuni challenge. A total of 2240 day-old Ross 708 males were randomly assigned within 8 experimental groups with a 4 × 2 factorial design, with 4 diets (negative control [CTL-], positive control [CTL+, bacitracin, 50 g/ ton], YCW constant dose [400 g/ton], and YCW step-down dose [SD, 800, 400, and 200 g/ton in the starter, grower, and finisher periods, respectively]) and with or without a Day-16 C. jejuni oral gavage challenge at a 103-colony-forming-units (CFU)/ml dose. Body weights and feed consumption were measured on Days 0, 14, 28, and 41 to determine broiler performance. Ileum tissue samples were collected from 24 birds per treatment on Days 17 and 24 (1 and 8 days postinoculation [PI]) for relative gene expression (RGE) analysis. Cecal content samples were collected from 24 birds per treatment on Days 24, 34, and 42 for C. jejuni enumeration and prevalence calculation. A total of 80 birds per treatment were processed to determine carcass yield on Day 44, and on Day 45, 16 carcass rinsates per treatment were collected for C. jejuni enumeration and prevalence calculation. The interaction between diet and inoculation did not influence growth performance (P > 0.05). However, a diet effect was observed in the starter period where birds fed SD diet had a lower feed conversion ratio than birds fed CTL- diet (P = 0.0165). Additionally, the treatment of birds inoculated with C. jejuni fed with SD had a trend to a lower feed conversion ratio during the grower period (P = 0.0550). The RGE of interleukin 1β and interleukin 10 was similar in all treatments 1 and 8 days PI. The RGE of avian beta defensin 10 was similar in all treatments on Day 1 PI, but different on Day 8 PI (P = 0.0476). All birds inoculated with C. jejuni had similar CFU per milliliter counts in the cecal contents at Days 24, 34, and 42 (P > 0.05), and all birds inoculated with phosphate-buffered saline were negative for C. jejuni after prevalence testing. After processing 1) carcass yield was similar in all treatments (P > 0.05); 2) C. jejuni-inoculated birds fed CTL- had lower CFU per milliliter counts than birds provided CTL+ and constant-dose diets (P = 0.0383); and 3) all birds inoculated with PBS were negative for Campylobacter. Overall, under the conditions of this study, the addition of YCW during a C. jejuni challenge did not have an impact on growth performance, innate immune response, cecal colonization, carcass yield, or carcass colonization after processing.

Investigating the Effect of Pulicaria jaubertii as a Natural Feed Additive on the Growth Performance, Blood Biochemistry, Immunological Response, and Cecal Microbiota of Broiler Chickens

Based on the biologically active compounds of Pulicaria jaubertii studied so far, there are no studies on the use of this plant in broilers. Therefore, the present study aims is to investigate the effect of Pulicaria jaubertii on the performance, blood biochemistry, internal organs, gene expression related to immune response, and the cecal microbiota of broiler chickens. A total of two hundred and forty male broilers were used and divided into four diet groups (T1 = 0, T2 = 3, T3 = 6, and T4 = 9 g Pulicaria jaubertii powder/kg basal diet). The performance evaluation, serum biochemical parameters, internal organ indicators, cytokines' gene expression, and microbiota colonization were determined. The study results showed that this plant was rich in nutrients, some fatty acids, and bioactive phenolic compounds. All growth performance indicators and relative liver weight were improved by Pulicaria jaubertii levels (T2 to T4) with no effect on feed intake. T3 and T4 showed higher total protein and lower triglycerides and total cholesterol. Birds fed Pulicaria jaubertii showed immune regulation through the modulation of pre-inflammatory cytokines and increased mucin-2 and secretory Immunoglobulin A compared with the control group. Diet groups (T2 to T4) had higher quantities of Lactobacillus spp. and lower levels of Salmonella spp. than the control group. We conclude that Pulicaria jaubertii could be used as a feed supplement for broilers due to its beneficial effects on overall performance, immune response, and microbiota. Further studies are recommended to investigate the potential mechanism of Pulicaria jaubertii in broilers.

The effect of Bacillus subtilis and its delivery route on hatch and growth performance, blood biochemistry, immune status, gut morphology, and microbiota of broiler chickens

This study evaluated the effect of probiotics (Bacillus subtilis fermentation extract) and its delivery route (in-feed or in ovo) on hatch and growth performance, blood biochemistry, immune status, gut morphology, and microbiota of broiler chickens. Hatching eggs were incubated for 21 d. On d 12, viable eggs were randomly allotted to 4 groups: the noninjected, in ovo saline (S), in ovo Bacillus subtilis 1 (P1), and in ovo Bacillus subtilis 2 (P2). On d 18, S, P1, and P2 groups received 0.2 mL saline diluent, 10 × 10⁶, and 20 × 10⁶ CFU of the bacterium via the amnion, respectively. At hatch, chicks were re-allotted to 5 new treatment groups: P1, P2, 0.005% in-feed Bacillus subtilis extract (P3), 0.05% in-feed bacitracin methylene disalicylate (BMD,), and corn-wheat-soybean diet negative control (NC) in 9 replicate pens (22 birds/pen) and raised for 35 d. Hatch parameters were assessed on d 0, and growth performance indices measured weekly. On d 25, 1 bird/cage was euthanized, and samples collected for further analysis. Data were analyzed by generalized linear model. Treatments S and P2 recorded higher (P = 0.01) chick BW/ Egg Weight values compared to the non-injected eggs. P3 and P2 reduced (P = 0.02) FI at week 5 compared to the NC treatment. However, no change in average body weight gain (ABG) and feed conversion ratio (FCR) were observed during the same period. At d 35, while BMD treatment showed a tendency (P = 0.09) to increase FI compared to the NC treatment, ABG and FCR were similar for all treatments. Blood sodium and chloride levels were increased (P < 0.05) by the BMD treatment compared to the NC treatment. Compared to other treatments, BMD and P3 treatments increased (P < 0.001) jejunal and ileal villus height to crypt depth ratios, respectively. However, P1 and P2 increased (P < 0.001) villus height to crypt depth ratio in the duodenum compared to NC treatment. Treatments did not affect gut microbial diversity; however, BMD treatment increased (P < 0.05) the proportion of bacteria in the genus Enterococcus in the ileum and reduced (P < 0.05) the proportion of bacteria in the genus Streptococcus in the ceca. All probiotics treatments (irrespective of route and dose) reduced (P < 0.001) the levels of serum IgG compared to the NC treatment. However, P1 and P2 had the lowest numerical decrease in serum IgG concentrations, suggesting that Bacillus subtilis (especially in ovo delivered) might provide broiler chickens with better immunological protection by neutralizing pathogenic organisms that could result in the production of natural antibodies.

Poultry nutrition

Nutrition is the most important environmental factor affecting development, health status, growth performance and profitability of poultry production. Feeds for poultry constitute up to 70–75% of total production costs. Poultry nutrition differs considerably from that of other livestock, which is determined by the specific anatomy of the gastrointestinal tract. Protein, energy, fat, fiber, minerals, vitamins, and water are of basic importance for poultry nutrition and their content in feeds must cover the requirement that differ depending on the bird’s age and species. In general, feed protein must be of good value including the content of essential amino acids. Among them lysine, methionine, cysteine, threonine and tryptophan are the limiting ones. The main ingredient of poultry feeds are cereal grains, i.e. wheat and maize, which predominantly constitute an energy source because their protein content is insufficient for birds. Because of that cereals cannot be the only feed for poultry and must be combined with protein sources such as soybean or rapeseed meal, legume seeds or protein concentrates. Despite birds’ requirement for nutrients and chemical composition of feeds are well known, nutrition must face many problems. One of the most important issues is to find alternatives to antibiotic growth promoters.

Effect of in ovo administration of Newcastle disease vaccine conjugated with Astragalus polysaccharide on growth performance, intestinal development, and mucosal immunity in broiler chickens

This study was conducted to investigate the effect of in ovo administration of a mixture of Astragalus polysaccharide (APS) and Newcastle disease vaccine (NDV) on growth performance, intestinal development, and mucosal immunity in newly hatched chicks. Six hundred specific-pathogen-free (SPF) Leghorn fertilised eggs were incubated in a commercial hatchery and divided into four groups: (a) control group injected with 1 ml of 0.9% physiological saline, (b) APS group injected with 1 ml of 1 mg/ml APS solution, and (c) NDV group injected with 1 ml of 10^4.0 EID₅₀ /dose of NDV solution, and (d) APS + NDV group injected with a mixture of 0.5 ml of 2 mg/ml APS plus 0.5 ml 10^4.0 EID₅₀ /dose ND vaccine (NDV) on Day 18.5 of incubation. The results showed that in ovo injection of APS or the mixture of APS and NDV increased the body weight at 1 day (IW) and final weight (FW) at 28 days and increased the feed conversion ratio (FCR) at 1-7, 8-14, 15-21, and 1-28 days of age. The villus height (VH) was increased (p < 0.05), and the crypt depth (CD) was decreased (p < 0.05) in the duodenum compared with the control group. The VH/CD ratios were increased (p < 0.05) in the APS + NDV group compared with controls, NDV group, and APS group on d3. The levels of slgA in washings were increased (p < 0.05) on Days 3, 7, 14, 21, and 28, and the number of IgA⁺ cells in the duodenum was increased on Days 7, 14, 21, and 28. In addition, the IgA⁺ cells were promoted from the villus root to the apex in the APS + NDV group. It can be concluded that in ovo administration of NDV conjugated with APS compared with NDV alone may be more effective in promoting growth performance and intestinal mucosal immunity.

Atrazine exposure and recovery alter the intestinal structure, bacterial composition and intestinal metabolites of male Pelophylax nigromaculatus

The pesticide atrazine poses a potential threat to the health of frogs living in farmland areas. The exposure concentration in traditional pesticide experiments is usually constant, while pesticide pollution in actual water may fluctuate due to periodic or seasonal application. We examined the effects of different concentrations of atrazine (50, 100 and 500 μg/L) over a 14-day exposure and a 7-day recovery on intestinal histology, bacterial composition and intestinal metabolites of male Pelophylax nigromaculatus. HE staining revealed that after a 14-day atrazine exposure, the 100 μg/L and 500 μg/L groups showed obvious cysts and significantly decreased intestinal crypt depth and villus height. After a 7-day recovery, the damaged intestine in the 100 μg/L group was partially recovered, while in the 500 μg/L exposure group there was no improvement. 16S rRNA gene analysis of intestinal bacteria showed that 500 μg/L atrazine exposure significantly caused a persistent decrease in bacterial α diversity. Compared to the control and other atrazine exposure groups, the 500 μg/L group showed significant changes in the relative abundance of predominant bacteria. In addition, most dominant bacteria in the 500 μg/L recovery group showed significant differences with the 50 μg/L and 100 μg/L recovery groups. Nontargeted metabolomics profiling based on UPLC/MS analysis showed that atrazine exposure and recovery induced changes in the intestinal metabolic profile. The changes in metabolites were mainly related to purine/pyrimidine metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism. In general, these pathways were closely related to energy metabolism and amino acid metabolism. These results suggest that the short-term exposure to 500 μg/L atrazine causes persistent harm to intestinal health. This study is an important step toward a better understanding of the toxic effects of atrazine exposure and recovery in frog intestines.

The control of poultry salmonellosis using organic agents: an updated overview

Salmonellosis is a severe problem that threatens the poultry sector worldwide right now. Salmonella gallinarium and Salmonella pullorum (Fowl typhoid) are the most pathogenic serovars in avian species leading to systemic infection resulting in severe economic losses in the poultry industry. Nontyphoidal serotypes of Salmonella (Paratyphoid disease) constitute a public health hazard for their involvement in food poisoning problems in addition to their zoonotic importance. Also, Salmonella species distribution is particularly extensive. They resisted environmental conditions that made it difficult to control their spread for a long time. Therefore, the current review aimed to through light on Salmonellosis in poultry with particular references to its pathogenesis, economic importance, immune response to Salmonella, Salmonella antibiotics resistance, possible methods for prevention and control of such problems using promising antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, cinnamaldehyde, chitosan, nanoparticles, and vaccines.

Potential Effects of Anthocyanin-Rich Roselle (Hibiscus sabdariffa L.) Extract on the Growth, Intestinal Histomorphology, Blood Biochemical Parameters, and the Immune Status of Broiler Chickens

The potential effects of anthocyanin-rich roselle, Hibiscus sabdariffa L. extract (ARRE) on the growth, carcass traits, intestinal histomorphology, breast muscle composition, blood biochemical parameters, antioxidant activity, and immune status of broiler chickens were evaluated. In the present study, Hibiscus acidified ethanolic extract was reported to have a total anthocyanin content of about 359.3 mg cyanidin 3-glucoside/100 g DW, total polyphenol concentration (TPC) of about 598 mg gallic acid equivalent (GAE)/100 g DW, and total flavonoids (TFs) of about 100 mg quercetin equivalent (QE)/100 g DW. Two-hundred-fifty one-day-old chicks (Ross 308 broiler) (87.85 gm ± 0.32) were randomly allotted to five experimental groups and fed on basal diets supplemented with five levels of ARRE: 0, 50, 100, 200, and 400 mg Kg−1 for 35 days. Dietary ARRE addition did not improve the birds’ growth and carcass traits. Supplemental ARRE increased the n-3 polyunsaturated fatty acids (PUFA) (ω-3) percentage in the breast muscle. Dietary ARRE increased the villous height, and the ARRE100 group raised the villus height to crypt depth ratio. Dietary ARRE increased the immunoexpression of immunoglobulin G (IgG) in the spleen. The serum thyroxine hormone (T4) level was higher in the ARRE200 group. The serum growth hormone level was increased by ARRE addition in a level-dependent manner. According to the broken-line regression analysis, the optimum inclusion level of ARRE was 280 mg Kg−1. All levels of supplemental ARRE decreased the serum triglyceride level. The serum total antioxidant capacity (TAC) was increased in the ARRE100-ARRE400 groups, the serum superoxide dismutase (SOD) level was increased in the ARRE200 group, and the serum malondialdehyde (MDA) level was decreased by increasing the ARRE level. Supplemental ARRE significantly increased the serum levels of lysozymes and IL10. The serum complement 3 (C3) level was increased in ARRE200 and ARRE400 groups. It can be concluded that dietary ARRE addition had many beneficial effects represented by the improvements in the bird’s metabolic functions, blood biochemistry, intestinal morphology, antioxidant activity, immune status, and higher ω-3 content in the breast muscles. However, it had no improving effect on the birds’ growth.

Essential Oil Delivery Route: Effect on Broiler Chicken's Growth Performance, Blood Biochemistry, Intestinal Morphology, Immune, and Antioxidant Status

Simple Summary

Much research is devoted to the search for potent alternatives to antibiotic growth promoters in the poultry industry. It is hypothesized that the efficacy of potential alternatives could be influenced by their type and the delivery strategy utilized. Consequently, this study evaluated the efficacy of a commercial essential oil blend across different delivery routes as a potent alternative to in-feed antibiotics in broiler chickens using selected biochemical, immune, and performance parameters. The results provide evidence that the successive delivery of essential oils via in ovo and in-water routes in broiler chickens offers the potential to improve broiler chicken biochemical and antioxidant status. However, the in ovo delivery of essential oil at 0.2 mL dosage (saline + essential oil, dilution ratio—2:1) suffers the limitations of reduced hatchability.

Abstract

This study evaluated the effect of an essential oil blend and its delivery routes on broiler chicken growth performance, blood biochemistry, intestinal morphology, and immune and antioxidant status. Eggs were incubated and allotted to 3 groups: non-injected group, in ovo saline group, and in ovo essential oil group. On day 18 of incubation, essential oil in saline or saline alone was injected into the amnion. At hatch, chicks were assigned to post-hatch treatment combinations (1) in ovo essential oil + in-water essential oil (in ovo + in-water EO); (2) in ovo essential oil (in ovo EO); (3) in ovo saline; (4) in-water essential oil; (5) in-feed antibiotics (Bacitracin methylene disalicylate) and (6) a negative control (NC; corn-wheat-soybean diet) in 8 replicate cages (6 birds/cage) and raised for 28 day. The in ovo EO group reduced (p < 0.05) chick length and hatchability, all groups recorded no difference in growth performance at 0–28 day. The in ovo + in-water EO treatment reduced (p < 0.05) blood creatine kinase and aspartate aminotransferase levels whilst increasing (p < 0.05) total antioxidant capacity in birds. The in ovo + in-water delivery of EO might represent a potential antibiotic reduction strategy for the poultry industry but more research is needed to address the concern of reduced hatchability.

Effect of yeast cell wall supplementation on intestinal integrity, digestive enzyme activity and immune traits of broilers

1. The protective layer formed by intestinal epithelial cells acts as a barrier preventing the adhesion of pathogenic bacteria, aids digestion and passage of nutrients and reduces damage caused from toxins on the gastrointestinal tract. This study was conducted to investigate the effects of a yeast cell wall-based product (YCW), on broiler intestinal integrity, digestive enzyme capacity and immune function.2. A 35-d trial involving 246, one-d-of-hatch male broiler chickens was carried out at a trial facility at Agri-Food Biosciences Institute (AFBI, Belfast, UK). Birds were randomly allocated into 6 pens at day of hatch (41 birds/pen; 123 birds/group). Pens were divided into two groups: (1) basal diet and (2) basal diet that incorporated YCW at the manufacturers' recommended inclusion levels (Alltech Inc., Lexington, Kentucky, USA).3. In this study, YCW supplementation affected broiler intestinal morphology resulting in greater crypt depth, villus height and surface area, goblet cell density and mucus layer thickness and lower muscularis mucosae thickness. The digestive enzymes, maltase, sucrase and alkaline phosphatase, were significantly higher in the YCW supplemented group compared to the control. The expression levels of pro-inflammatory cytokines, IL-1β, IL-12 and IL-18, were significantly lower as was necroptotic cell death in YCW supplemented birds.4. In conclusion, under the conditions of this study, YCW supplementation positively affected intestinal health parameters in broilers following 35-d supplementation.

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 carbohydrate effects on histological features of ileal mucosa in White Leghorn chicken

White Leghorn chickens were divided into the control, low-carbohydrate (CHO), and CHO-free groups to investigate dietary CHO’s significance on histological features of chicken ileal mucosa. Paraffin sections of distal ileum from each chicken were stained by periodic acid-Schiff reaction and subjected to morphometrical analysis. Most villi in the control group had a fingerlike shape but those of the experimental groups showed irregular shapes. Villus height, crypt depth and the number of mitotic cells per crypt were significantly lower in the CHO-free group than in the control group. The density of goblet cells also showed a significant decreasing trend with a reduction in dietary CHO level. In conclusion, dietary CHO positively affects the proliferation of epithelial cells in the chicken ileum.

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.

Bacillus subtilis delivery route: effect on growth performance, intestinal morphology, cecal short-chain fatty acid concentration, and cecal microbiota in broiler chickens

As the poultry industry recedes from the use of antibiotic growth promoters, the need to evaluate the efficacy of possible alternatives and the delivery method that maximizes their effectiveness arises. This study aimed at expounding knowledge on the effect of the delivery method of a probiotic product (Bacillus subtilis fermentation extract) on performance and gut parameters in broiler chickens. A total of 450 fertile eggs sourced from Cobb 500 broiler breeders were randomly allotted to 3 groups: in ovo probiotic (n = 66), in ovo saline (n = 66), and noninjection (n = 200) and incubated for 21 d. On day 18.5 of incubation, 200 μL of either probiotic (10 × 10⁶ cfu) or saline was injected into the amnion. At hatch, chicks were reallotted to 6 new treatment groups: in ovo probiotic, in ovo saline, in-feed antibiotics, in-water probiotic, in-feed probiotics, and control (corn-wheat-soybean diet) in 6 replicate cages and raised for 28 d. Of all hatch parameters evaluated, only percentage pipped eggs was found significant (P < 0.05) with the noninjection group having higher percentage pipped eggs than the other groups. Treatments did not affect the incidence of necrotic enteritis on day 28 (P > 0.05). Irrespective of the delivery method, the probiotic treatments had no significant effect on growth performance. The ileum villus width of the in ovo probiotic treatment was 18% higher than the in ovo saline group (P = 0.05) but not statistically higher than other groups. The jejunum villus height was 23% higher (P = 0.000) in the in ovo probiotic group than in the control group. There was no effect of treatment on total cecal short-chain fatty acid concentration and cecal gut microbiota composition and diversity (P > 0.05), although few unique bacteria differential abundance were recorded per treatment. Conclusively, although probiotic treatments (irrespective of the delivery route) did not affect growth performance, in ovo delivery of the probiotic product enhanced intestinal morphology, without compromising hatch performance and gut homeostasis.

Effects of dietary pyrroloquinoline quinone disodium supplementation on inflammatory responses, oxidative stress, and intestinal morphology in broiler chickens challenged with lipopolysaccharide

This study was conducted to investigate the effects of pyrroloquinoline quinone disodium (PQQ·Na2) on inflammatory responses, oxidative stress, and intestinal morphology of broiler chickens challenged with lipopolysaccharide (LPS). A 2 × 2 factorial arrangement in a complete randomized design experiment was used to study the effect of dietary PQQ·Na2 (0 or 1 mg/kg) on broiler chickens with or without a challenge with LPS. A total of two hundred eighty-eight 1-day-old Arbor Acre broiler chickens were randomly assigned to 4 treatments with 6 replicate cages of 12 birds per cage. All experimental broilers were injected intraperitoneally with 0.5 mg/kg body weight of either Escherichia coli LPS or sterile saline at 16, 18, and 20 d of age. Results showed that injecting LPS significantly increased the concentrations of interleukin-1beta (IL-1β) in serum of birds on day 20 and day 21. Meanwhile, LPS injection increased (P < 0.05) the relative mRNA expression of interleukin-6 (IL-6) in the duodenal mucosa of broilers on day 21. However, dietary supplementation with PQQ·Na2 decreased (P < 0.05) the concentration of IL-6 in serum of birds on day 20 and the levels of IL-1β, IL-6, and interleukin-10 (IL-10) in serum of broiler chickens on day 21. Besides, supplementation of PQQ·Na2 within diet decreased (P < 0.05) the mRNA expressions of IL-1β and IL-10 in the duodenal mucosa of birds on day 20. Relative to saline injection, the activity of glutathione peroxidase (GSH-Px) in serum and the activities of total superoxide dismutase (T-SOD) and catalase (CAT) in liver were found to be lower (P < 0.05) in broilers after LPS challenge on day 21. However, birds fed with PQQ·Na2 showed higher (P < 0.05) GSH-Px activity in serum and higher (P < 0.05) T-SOD activities in liver on day 21 and day 42. Pyrroloquinoline quinone disodium also significantly attenuated the LPS-induced decreases in villus height to crypt depth ratio in the duodenum of broilers. In conclusion, dietary PQQ·Na2 supplementation significantly exerted protective effects on inflammation damage and oxidant stress of broilers under LPS challenge by regulating the expression of inflammatory cytokines (IL-1β, IL-6, and IL-10) and activities of antioxidant enzymes (GSH-Px, T-SOD, and CAT). Moreover, dietary PQQ·Na2 supplementation significantly ameliorated the LPS-impaired intestinal morphology in broilers. Therefore, it has been considered that PQQ·Na2 can be used as a potential feed additive in broiler 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.

Effect of dietary supplementation with yeast cell wall extracts on performance and gut response in broiler chickens

Background

The dietary supplementation of yeast cell wall extracts (YCW) has been found to reduce pathogenic bacteria load, promote immunoglobulin production, prevent diseases by pro-inflammatory responses, and alter gut microbiota composition. This study evaluated growth and slaughter results, health, gut morphology, immune status and gut transcriptome of 576 male chickens fed two diets, i.e. C (control) or Y (with 250-500 g/t of YCW fractions according to the growth period). At 21 and 42 d the jejunum of 12 chickens per diet were sampled and stained with hematoxylin/eosin for morphometric evaluation, with Alcian-PAS for goblet cells, and antibodies against CD3+ intraepithelial T-cells and CD45+ intraepithelial leukocytes. The jejunum sampled at 42 d were also used for whole-transcriptome profiling.

Results

Dietary YCW supplementation did not affect final live weight, whereas it decreased feed intake (114 to 111 g/d; P ≤ 0.10) and improved feed conversion (1.74 to 1.70; P ≤ 0.01). Regarding the gut, YCW supplementation tended to increase villi height (P = 0.07); it also increased the number of goblet cells and reduced the density of CD45+ cells compared to diet C (P < 0.001). In the gut transcriptome, four genes were expressed more in broilers fed diet Y compared to diet C, i.e. cytochrome P450, family 2, subfamily C, polypeptide 23b (CYP2C23B), tetratricopeptide repeat domain 9 (TTC9), basic helix-loop-helix family member e41 (BHLHE41), and the metalloreductase STEAP4. Only one gene set (HES_PATHWAY) was significantly enriched among the transcripts more expressed in broilers fed diet Y. However, a total of 41 gene sets were significantly over-represented among genes up-regulated in control broilers. Notably, several enriched gene sets are implicated in immune functions and related to NF-κB signaling, apoptosis, and interferon signals.

Conclusions

The dietary YCW supplementation improved broiler growth performance, increased gut glycoconjugate secretion and reduced the inflammatory status together with differences in the gut transcriptome, which can be considered useful to improve animal welfare and health under the challenging conditions of intensive rearing systems in broiler chickens.

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.

Effect of Carotenoids, Oligosaccharides and Anthocyanins on Growth Performance, Immunological Parameters and Intestinal Morphology in Broiler Chickens Challenged with Escherichia coli Lipopolysaccharide

This study was conducted to investigate the effect of carotenoid, oligosaccharide and anthocyanin supplementation in broiler diets under Escherichia coli lipopolysaccharide (LPS) challenge. Ross 308 chickens were fed 5 diets: basal diet (control diet), diet supplemented with β-glucan in 0.05% (positive control) and diets with 0.5% carotenoid-, oligosaccharide- or anthocyanin contents. On the 26th days of age, chickens were challenged intraperitoneally 2 mg LPS per kg of body weight. 12 h after injection, birds were euthanized, then spleen and ileum samples were collected. LPS induced increased relative mRNA expression of splenic (p = 0.0445) and ileal (p = 0.0435) interleukin-1β (IL-1β), which was lower in the spleen in carotenoid (p = 0.0114), oligosaccharide (p = 0.0497) and anthocyanin (p = 0.0303)-treated chickens compared to LPS-injected control birds. Dietary supplementation of carotenoids also decreased relative gene expression of splenic interleukin-6 (IL-6) (p = 0.0325). In the ileum, β-glucan supplementation showed lower relative mRNA expression of toll-like receptor 5 (TLR-5) (p = 0.0387) compared to anthocyanin treatment. Gene expression of both splenic and ileal interferon-α (IFN-α), interferon-γ (IFN-γ), toll-like receptor 4 (TLR-4) and toll-like receptor 5 (TLR-5) were not influenced by dietary supplements. In conclusion, carotenoids, oligosaccharides and anthocyanins could partially mitigate the immune stress caused by LPS challenge. All of the compounds impacted longer villus height (p < 0.0001), villus height:crypt depth ratios were higher after β-glucan (p < 0.0001) and anthocyanin (p = 0.0063) supplementations and thickened mucosa was observed in β-glucan (p < 0.0001), oligosaccharide (p < 0.0001) and anthocyanin (p = 0.048) treatments. All of these findings could represent a more effective absorption of nutrients.

Effects of Different Probiotics on Laying Performance, Egg Quality, Oxidative Status, and Gut Health in Laying Hens

With recent bans on the growth-promoting use of antibiotics, alternative strategies are needed to improve the performance of agricultural animals. Here, the effects of dietary supplementation with Clostridium butyricum and a combination of Saccharomyces boulardii and Pediococcus acidilactici were assessed on laying performance, egg quality, oxidative status, and gut health in laying hens. A total of 8208 Lohmann pink laying hens were divided into 3 treatment groups, with each group replicated 12 times (n = 228). Hens in the control group (CON) were provided a basic diet devoid of added antibiotics and probiotics. Treatment group 1 (T1) received the same base diet supplemented with 0.5 g/kg C. butyricum, and the diets of treatment group 2 (T2) supplemented with S. boulardii (0.05 g/kg) and P. acidilactici (0.1 g/kg) for the entirety of the 5-week trial. The data indicated that C. butyricum supplementation resulted in a significant reduction in ADFI, a significant increase in feed conversion, eggshell strength, and the CP% of albumen (dry matter, DM) relative to CON. The probiotic-treated hens exhibited decreased reactive oxygen species (ROS) levels in ileum and cecum, and reduced malondialdehyde (MDA) in serum. In conclusion, dietary supplementation with C. butyricum may be beneficial with respect to hen performance, egg quality, and gut health.

Immune modulation, growth performance, and nutrient retention in broiler chickens fed a blend of phytogenic feed additives

This study aimed to assess the effect of a commercial blend of phytogenic feed additives (PA), comprising 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin on the modulation of immune biomarkers of broiler chickens, their growth performance, dietary energy, and nutrient retention. Four-hundred day-old birds were assigned to one of four dietary treatments. Two control diets based on either wheat (WC) or maize (MC) were each given with and without PA at 100 g/t. Growth performance variables including feed intake (FI), weight gain (WG), and feed conversion ratio (FCR) were recorded. Dietary N-corrected apparent metabolizable energy (MEn), dry matter (DMR), nitrogen (NR), and fat retention (FR) coefficients were also determined. Gene expression of immune biomarkers (cytokines) were determined in caecal tonsil tissue from 21 d old birds. Expression of IL2, IL18, IL10, and IL17C in the caecal tonsils were upregulated (P < 0.05) in the birds fed MC-based diets compared to the WC fed birds. Feeding PA supplemented diets downregulated the expression of CD40LG (P < 0.001), IFNG, and IL6 (P < 0.05). There was a cereal type × PA interaction (P < 0.05), as expression of IFNB was downregulated in the birds fed PA supplemented MC but not WC. However, expression of IL12B was downregulated in birds fed PA supplemented WC but there was no significant (P > 0.05) change in expression levels in birds fed MC diets. Feeding MC diets gave greater FI (P < 0.001) and ME (P < 0.05), but lower FCR (P < 0.05) compared to birds fed WC diets. The WG and nutrient retention coefficients were not affected (P > 0.05) by cereal type. Supplementary PA improved FI (P < 0.05), WG (P < 0.001), FCR (P < 0.05), MEn (P < 0.05), MEn: GE ratio (P < 0.05), and FR (P < 0.05). In conclusion, dietary inclusion of PA improved overall growth performance variables, energy, and nutrient retention and intestinal cytokine expression.

Mannan oligosaccharide supplementation in diets of sow and (or) their offspring improved immunity and regulated intestinal bacteria in piglet1

The objectives of the current study were to explore the effects of mannan oligosaccharide (MOS) supplementation in the diets of sow and (or) their offspring on intestinal bacteria, intestinal and systemic inflammation in the piglet. A total of 60 multiparous sows (4 ± 1 parity; Landrace × Yorkshire) were fed either control diet (sCON, n = 30) or a diet containing 400 mg kg-1 MOS (sMOS, n = 30) from day 86 of gestation until weaning (day 20 of postpartum). On day 7 of age, offspring (Duroc × Landrace Yorkshire) were assigned within sow treatments and fed control diet (pCON) or diet containing 800 mg kg-1 MOS (pMOS) for 28 d (end at 35 d of age), resulting in four piglet diet groups (n = 15 litters per diet group): sCON-pCON, sCON-pMOS, sMOS-pCON, and sMOS-pMOS. Results found that piglet diet MOS increased or tend to increase Lactobacillus amount in the ileum digesta (P < 0.01) and jejunum digesta (P = 0.07), respectively; while tend to decrease Escherichia coli amount in jejunum digesta (P =0.06) and cecum digesta (P = 0.08). Both sow and piglet diets add MOS (sMOS-pMOS) increased Lactobacillus amount but decreased E. coli amount in jejunum digesta (P < 0.05) compared with the sCON-pCON diet group. In addition, sow diet MOS (rather than piglet diet MOS) increased sIgA content in piglet jejunum mucosa compared with control (P = 0.04). Sow diet MOS decreased toll-like receptor 2 (TLR2), toll-like receptor 4 (TLR4), and interleukin 8 (IL-8) mRNA levels (P < 0.05) and tended to decrease nuclear factor-κB p65 (NF-κB p65) mRNA level (P = 0.07) in piglet intestinal lymphatic. The interaction effects between sow and piglet diets were found on the mRNA levels of NF- κB p65 (P = 0.03) and IL-8 (P = 0.02) in piglet jejunum. Finally, the sow diet MOS decreased proinflammatory cytokines IL-2 (P < 0.01) and IL-4 (P < 0.01) concentrations in piglet serum. Piglets diet MOS decreased the contents of IL-2 (P = 0.03), IL-4 (P = 0.01) and interferon (IFN)-γ (P < 0.01) while increased anti-inflammatory cytokine IL-10 (P < 0.01) content in serum. The interaction effects between sows and piglet diets on IL-4 (P = 0.02), IL-10 (P < 0.01), and IFN-γ (P = 0.08) were observed. In conclusion, sow and/or piglet diet MOS could improve intestinal microbiota, enhance intestinal mucosal immune competence, and suppress intestinal and systemic inflammation in the piglet.

Effects of Mannanoligosaccharide Supplementation on the Growth Performance, Immunity, and Oxidative Status of Partridge Shank Chickens

Mannanoligosaccharides (MOS) can be used in poultry production to modulate immunity and improve growth performance. So, we hypothesized that our enzymatic MOS could achieve the same effects in broilers. To investigate this, a total of 192 one-day-old Partridge Shank chickens were allocated to four dietary treatments consisting of six replicates with eight chicks per replicate, and they were fed a basal diet supplemented with 0, 0.5, 1 and 1.5 g MOS per kg of diet(g/kg) for42 days. Treatments did not affect the growth performance of chickens. Dietary MOS linearly increased the relative weight of the bursa of Fabricius and jejunal immunoglobulin M (IgM) and immunoglobulin G (IgG) content, whereas it linearly decreased cecal Salmonella colonies at 21 days (p < 0.05). The concentration of jejunal secretory immunoglobulin A (sIgA) and IgG at 42 days as well as ileal sIgA, IgG, and IgM at 21 and 42 days were quadratically enhanced by MOS supplementation (p < 0.05). Also, chickens fed MOS exhibited linear and quadratic reduction in jejunal malondialdehyde (MDA) accumulation (p < 0.05). In conclusion, this enzymatic MOS can improve the immune function and intestinal oxidative status of Partridge Shank chickens.

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.

Influence of dietary supplementation of autolyzed whole yeast and yeast cell wall products on broiler chickens

Objective

This study evaluated the effect of yeast products on growth performance, visceral organ weights, endogenous enzyme activities, ileal nutrient digestibility and meat yield of broiler chickens fed diets containing autolyzed whole yeast (WY) and yeast cell walls (YCW) at varying levels of inclusion.

Methods

Nine dietary treatments consisting of WY or YCW included at 0.5, 1.0, 1.5, or 2.0 g/kg diet and a control diet without yeast supplementation was used in the experiment. Each of the nine treatments was replicated six times with nine birds per replicate. Birds were housed in cages, in climate-controlled rooms and fed starter, grower and finisher diets.

Results

There was an improvement (p<0.05) in body weight gain and feed conversion ratio on d 10, 24, and 35 for birds fed 1.0 to 2.0 g/kg WY or YCW diet. Small intestine weight was heavier on d 10 and 24 for birds on higher levels of WY and YCW compared to the control group. On d 10 and 24, there was a significant increase (p<0.05) in tissue protein content and pancreatic enzyme activities (trypsin and chymotrypsin) of birds on 1.5 to 2.0 g/kg WY and YCW diets compared to the control group. Compared to the control group, birds on WY (2.0 g/kg diet) and YCW (at 1.5 and 2.0 g/kg diet) had better (p<0.05) protein digestibility on d 24. On d 35, there was significant improvement (p<0.05) in percentage of carcass, absolute and relative breast weight for broiler chickens fed WY and YCW mostly at 2 g/kg diet compared to birds on the control diet.

Conclusion

Supplementation of diets with autolyzed WY and YCW products especially at 1.5 to 2.0 g/kg diet improved broiler chicken performance and meat yield through their positive effects on ileal protein digestibility and pancreatic enzyme activities.

Mannan rich fraction from yeast modulates inflammatory responses in intestinal cells (HT-29) exposed toEscherichia coli

Mannan from yeast has been demonstrated to limit infection in animals susceptible to gastrointestinal infection, including pigs, poultry and cows, by blocking the mechanism by which gram-negative bacteria adhere to and invade the intestines. EnterotoxigenicEscherichia coli(ETEC) cause post weaning diarrhoea (PWD) which results in poor weight gain and potential death at great economic cost to the farmer. A mannan rich fraction (MRF) was assessedin vitrofor its impact on ETEC infection of HT-29 intestinal cell line. Gene expression markers for inflammation (TNFαandIL-1β) and TLR4 (TICAM-1andLY96) associated recognition of bacteria were significantly elevated following exposure toE. colialone, but not in combination with MRF compared to the control. HT-29 cells exposed to MRF alone demonstrated significantly reduced expression of immune signalling genesIRAK1,IRF7andJUNwhen compared to the control. HT-29 cell protein abundance for TNFα and TLR4 associated proteins were significantly increased in response toE. coliexposure alone while no significant change was observed for MRF treatment withE. coliinfection.E. coliadhesion to HT-29 cells was significantly decreased with addition of MRF compared toE. coliinfection alone. The action of MRF demonstrated its potential capacity to limit infection on anin vitrolevel through blocking bacterial interaction with the intestines that leads to infection as marked by a reduction in proinflammatory responses. MRF on its own demonstrated potential anti-inflammatory effects on intestinal cells with the reduction of proinflammatory responses observed.

Benefits of probiotics and/or prebiotics for antibiotic-reduced poultry

Antibiotics have been used for many years as growth promoters. They contribute to build the immunocompetence (i.e. ability of the body to produce a normal immune response following exposure to an antigen) of birds against infectious diseases and as growth promoters. Antibiotics have been widely used as growth promoters in the field of animal production since 1940s. There is a hypothesis that is effect is brought about by dynamic biological interaction with the micro-flora in the intestine. In 1951, the United States Food and Drug Administration approved the use of antibiotics as animal additives to prevent disease in general and, in some cases, to improve efficiency without veterinary prescription. In the 1950s and 1960s, each European state approved its own national regulations about the use of antibiotics in animal feeds. However, using antibiotics may develop bacteria resistant to these drugs. Accordingly, the use of antibiotics has been minimized and replaced by effective dietary supplements such as probiotics and/or prebiotics that are claimed to enhance growth and positively modulate the immune response. The current review paper sheds light on the benefits of using probiotics and/or prebiotics in poultry feed versus the risk of using antibiotics and the mechanisms by which they exert their effects, as well as the economic analysis of using these beneficial additives in poultry feed.

Effects of Pediococcus acidilactici, mannan-oligosaccharide, butyric acid and their combination on growth performance and intestinal health in young broiler chickens challenged with Salmonella Typhimurium

This study compared the efficacy of Pediococcus acidilactici, mannan-oligosaccharide, butyric acid, and their combination on growth performance and intestinal health in broiler chickens challenged with S. Typhimurium. Ross 308 male broilers (n = 420) were randomly assigned to one of the 6 treatments, resulting in 5 replicate pens of 14 chicks per treatment. The treatments included a negative control [(NC), no additive, not challenged]; positive control [(PC), no additive, but challenged with S. Typhimurium at d 3 posthatch], and 4 groups whereby birds were challenged with S. Typhimurium at d 3 posthatch and fed diets supplemented with either probiotic [0.1 g/kg Pediococcus acidilactici (PA)], prebiotic [2 g/kg mannan-oligosaccharides (MOS)], organic acid [0.5 g/kg butyric acid (BA)], or a combination of the 3 additives (MA). The S. Typhimurium challenge decreased feed intake, body weight gain and increased feed conversion ratio and reduced jejunum villus height (VH) and VH to crypt depth (CD) ratio (P < 0.05). Birds on the MA treatment exhibited similar performance to birds on the NC treatment (P > 0.05) and had a lower population of Salmonella in the ceca compared with birds on the PC treatment, at d 14 and 21 post-challenge (P < 0.05). The lowest heterophil to lymphocyte ratio was observed in birds on the MA and NC treatments (P < 0.05). Birds fed diets supplemented with MA or PA had greater VH and VH: CD ratio than birds on the PC treatment at d 7, 14 and 21 d post-challenge (P < 0.05). Suppressed amylase and protease activity was observed as a result of the S. Typhimurium challenge; the enzyme levels were restored in birds fed the additive-supplemented diets, when compared to the birds on the PC treatment, particularly at d 21 post-challenge (P < 0.05). These results indicate that dietary supplementation with a combination of PA, BA, and MOS in broiler chickens could be used as an effective tool for controlling S. Typhimurium and promoting growth performance.

Dietary yeast-derived mannan oligosaccharides have immune-modulatory properties but do not improve high fat diet-induced obesity and glucose intolerance

The indigestible mannan oligosaccharides (MOS) derived from the outer cell wall of yeast Saccharomyces cerevisiae have shown potential to reduce inflammation. Since inflammation is one of the underlying mechanisms involved in the development of obesity-associated metabolic dysfunctions, we aimed to determine the effect of dietary supplementation with MOS on inflammation and metabolic homeostasis in lean and diet-induced obese mice. Male C57BL/6 mice were fed either a low fat diet (LFD) or a high fat diet (HFD) with, respectively, 10% or 45% energy derived from lard fat, with or without 1% MOS for 17 weeks. Body weight and composition were measured throughout the study. After 12 weeks of intervention, whole-body glucose tolerance was assessed and in week 17 immune cell composition was determined in mesenteric white adipose tissue (mWAT) and liver by flow cytometry and RT-qPCR. In LFD-fed mice, MOS supplementation induced a significant increase in the abundance of macrophages and eosinophils in mWAT. A similar trend was observed in hepatic macrophages. Although HFD feeding induced a classical shift from the anti-inflammatory M2-like macrophages towards the pro-inflammatory M1-like macrophages in both mWAT and liver from control mice, MOS supplementation had no effect on this obesity-driven immune response. Finally, MOS supplementation did not improve whole-body glucose homeostasis in both lean and obese mice.Altogether, our data showed that MOS had extra-intestinal immune modulatory properties in mWAT and liver. However these effects were not substantial enough to significantly ameliorate HFD-induced glucose intolerance or inflammation.

Dietary Mannan Oligosaccharides Modulate Gut Microbiota, Increase Fecal Bile Acid Excretion, and Decrease Plasma Cholesterol and Atherosclerosis Development

SCOPE

Mannan oligosaccharides (MOS) have proven effective at improving growth performance, while also reducing hyperlipidemia and inflammation. As atherosclerosis is accelerated both by hyperlipidemia and inflammation, we aim to determine the effect of dietary MOS on atherosclerosis development in hyperlipidemic ApoE*3-Leiden.CETP (E3L.CETP) mice, a well-established model for human-like lipoprotein metabolism.

METHODS AND RESULTS

Female E3L.CETP mice were fed a high-cholesterol diet, with or without 1% MOS for 14 weeks. MOS substantially decreased atherosclerotic lesions up to 54%, as assessed in the valve area of the aortic root. In blood, IL-1RA, monocyte subtypes, lipids, and bile acids (BAs) were not affected by MOS. Gut microbiota composition was determined using 16S rRNA gene sequencing and MOS increased the abundance of cecal Bacteroides ovatus. MOS did not affect fecal excretion of cholesterol, but increased fecal BAs as well as butyrate in cecum as determined by gas chromatography mass spectrometry.

CONCLUSION

MOS decreased the onset of atherosclerosis development via lowering of plasma cholesterol levels. These effects were accompanied by increased cecal butyrate and fecal excretion of BAs, presumably mediated via interactions of MOS with the gut microbiota.

Optimal sulfur amino acid to lysine ratio for post weaning piglets reared under clean or unclean sanitary conditions

Two 14-day experiments, each with 90 (Duroc × [Yorkshire × Landrace]; 7.3 ± 0.6 kg) piglets, were conducted to determine the optimum sulfur amino acid (SAA) to lysine (Lys) ratio (SAA:Lys) for piglets when reared under clean or unclean sanitary conditions using performance and non-performance response criteria. Piglets were randomly assigned to the following dietary treatments. The basal diet contained 1.18% standardized ileal digestible (SID) Lys, and the SAA:Lys was 52%. In diets 2 to 5, the basal diet was supplemented with 4 graded levels of dl-Met to make SAA:Lys of 56%, 60%, 64% and 68%. In Exp. 1, piglets were housed in disinfected clean room. In Exp. 2, piglets were housed in a room previously occupied by other pigs and was not disinfected. On the last day, blood was collected to measure plasma urea nitrogen (PUN) and one pig per pen was euthanized to collect jejunal tissue to measure villus height (VH), crypt depth (CD), and VH:CD. In Exp. 1, increasing SAA:Lys linearly and quadratically increased VH and VH:CD (P < 0.05). In Exp. 2, increasing SAA:Lys linearly increased (P < 0.05) VH and VH:CD and linearly and quadratically decreased PUN (P < 0.05). Estimated PUN and VH-based optimum SAA:Lys requirements for clean and unclean sanitary condition were 60%, 63% and 66%, respectively.

Gut Health of Pigs: Challenge Models and Response Criteria with a Critical Analysis of the Effectiveness of Selected Feed Additives - A Review

The gut is the largest organ that helps with the immune function. Gut health, especially in young pigs has a significant benefit to health and performance. In an attempt to maintain and enhance intestinal health in pigs and improve productivity in the absence of in-feed antibiotics, researchers have evaluated a wide range of feed additives. Some of these additives such as zinc oxide, copper sulphate, egg yolk antibodies, mannan-oligosaccharides and spray dried porcine plasma and their effectiveness are discussed in this review. One approach to evaluate the effectiveness of these additives in vivo is to use an appropriate disease challenge model. Over the years, researchers have used a number of challenge models which include the use of specific strains of enterotoxigenic Escherichia coli, bacteria lipopolysaccharide challenge, oral challenge with Salmonella enteric serotype Typhimurium, sanitation challenge, and Lawsonia intercellularis challenge. These challenge models together with the criteria used to evaluate the responses of the animals to them are also discussed in this review.

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

This study evaluated the effect of yeast-derived products on growth performance, serum antibody levels, and mRNA gene expression of pattern-recognition receptors, and cytokines in broiler chickens. Two hundred and sixteen one-day-old male broiler chickens (Ross-308) were randomly assigned to six dietary treatments with six replicates (cage) of 6 birds per cage. Dietary treatments consisted of a Control diet without antibiotics (C), and diets containing 11 mg/kg of "virginiamycin", 0.25% of yeast cell wall (YCW), 0.2% of a commercial product "Maxi-Gen Plus" containing processed yeast and nucleotides, 0.05% of nucleotides, or a diet containing 8% of distiller's dried grains with solubles (DDGS). On d 21 post-hatch blood samples were collected from 6 birds per treatment and serum sample were analyzed for antibody levels. After blood sampling, birds were injected intraperitoneally with 3 mg/kg of BW of lipopolysaccharide (LPS). The unchallenged group was fed the Control diet and injected with saline solution. Spleen samples were collected to measure the gene expression of toll-like receptors (TLR)2b, TLR4, and TLR21, macrophage mannose receptor (MMR), and cytokines including interleukin (IL)-12, IL-10, IL-4, IL-6, IL-18, and interferon (IFN)-γ. No significant difference in body weight gain, feed intake, and FCR were observed among treatments. Regarding humoral immunity, the diet supplemented with YCW increased serum immunoglobulin (Ig)A level compared with the antibiotic group; however, serum concentrations of IgG and IgM were not affected by dietary treatments. Relative gene expression of TLR2 and TLR4 was not affected by dietary treatments, whereas the expression of TLR21 and MRR was upregulated in diets containing YCW and DDGS. The diet supplemented with YCW increased the expression of all cytokines, and expression of IFN-γ was upregulated in the DDGS group. However, no significant difference was observed for cytokine gene expression in the antibiotic and nucleotide diets. In conclusion, supplementation of diet with YCW stimulated the systemic innate immune responses of broiler chickens following challenge with LPS.

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on antibody-mediated immune response and gene expression of pattern recognition receptors and cytokines in broiler chickens immunized with T-cell dependent antigens

This study evaluated the effect of yeast-derived products on innate and antibody mediated immune response in broiler chickens following immunization with sheep red blood cells (SRBC) and bovine serum albumin (BSA). One-day-old male broiler chickens (Ross-308) were randomly assigned to 6 dietary treatments of 9 replicate cages of 5 birds each per treatment. Dietary treatments consisted of a Control diet without antibiotic, and diets containing 11 mg/kg of virginiamycin, 0.25% of yeast cell wall (YCW), 0.2% of a commercial product Maxi-Gen Plus containing processed yeast and nucleotides, 0.05% of nucleotides, or a diet containing 10% of DDGS. On days 21 and 28 post-hatching, 5 birds per treatment were immunized intramuscularly with both SRBC and BSA. One week after each immunization, blood samples were collected. Serum samples were analyzed by hemagglutination test for antibody response to SRBC, and by ELISA for serum IgM and IgG response to BSA. On d 35, 5 birds per treatment were euthanized and the tissue samples from the cecal tonsils were collected to assess the gene expression of toll-like receptors TLR2b, TLR4, and TLR21, monocyte mannose receptor (MMR), and cytokines IL-10, IL-13, IL-4, IL-12p35, and IFN-γ. The results for gene expression analysis demonstrated that the diet supplemented with YCW increased the expression of TLR2b and T-helper type 2 cytokines IL-10, IL-4, and IL-13 relative to the Control; and the expression of TLR4 and IL-13 was upregulated in the nucleotide-containing diet. However, the diets containing antibiotics or Maxi-Gen Plus downregulated the expression of IFN-γ compared to the control. The primary antibody response to SRBC was not affected by diets. However, the diet containing YCW increased the secondary antibody response to SRBC compared to the antibiotic treatment. Neither primary nor secondary IgG and IgM response against BSA were affected by diets. In conclusion, supplementation of the diet with YCW stimulated Th2 cell-mediated immune response indicating the immunomodulatory activities of these products following immunization with non-inflammatory antigens.