The impact of synbiotic administration through in ovo technology on the microstructure of a broiler chicken small intestine tissue on the 1st and 42nd day of rearing

In-ovo injection of Bacillus subtilis, raffinose, and their combinations enhances hatchability, gut health, nutrient transport- and intestinal function-related genes, and early development of broiler chicks

An experiment was conducted to assess the response of chicks to in-ovo injection of Bacillus subtilis (probiotic), raffinose (prebiotic), and their combinations. The study used 1,500 embryonated eggs allotted to 10 groups/ 6 replicates (150 eggs/group). The experimental treatments were: 1) un-injected control (NC); 2) sham (sterile distilled water) (PC); 3) probiotic 4 × 105CFU/egg (LBS); 4) probiotic 4 × 106CFU/egg (HBS); 5) prebiotic 2 mg/egg (LR); (6 prebiotic 3 mg/egg (HR); 7) probiotic 4 × 105CFU + prebiotic 2 mg/egg (LBS+LR); 8) probiotic 4 × 105CFU + prebiotic 3 mg/egg (LBS+HR); 9) probiotic 4 × 106CFU + prebiotic 2 mg/egg (HBS+LR); and 10) probiotic 4 × 106CFU + prebiotic 3 mg/egg (HBS+HR). Results showed that in-ovo inclusion of Bacillus subtilis, prebiotic, and their combinations improved hatchability, yolk-free chick weight, and chick weight compared to the control group. Moreover, the in-ovo treatment reduced residual yolk weight on the day of hatch compared to the control group. Different levels of in-ovo B. subtilis alone or combined with raffinose significantly (P ≤ 0.001) reduced total bacterial count and total yeast and mold count compared to the negative control group. Total coliform and E. coli decreased significantly (P ≤ 0.001) in groups treated with probiotics, prebiotics, and synbiotics with different doses during incubation compared to those in the control. Clostridium spp. was not detected in the groups injected with B. subtilis alone or combined with raffinose. In-ovo probiotics and synbiotics (LBS+LR & LBS+HR) significantly (P ≤ 0.001) increased ileal villus length compared to other groups. In-ovo treatment increased mRNA expression of JAM-2 compared to the control group. The fold change significantly increased in group LBS+HR for genes MUC-2, OCLN, VEGF, SGLT-1, and EAAT-3 compared to the negative control. In conclusion, in-ovo injection of a low dose of B. subtilis plus a high or low dose of raffinose can positively affect hatching traits, cecal microbial populations, intestinal histomorphometry, nutrient transport- and intestinal function-related genes, and chick quality of newly hatched broiler chicks.

Effect of different synbiotic administration methods on growth, carcass characteristics, ileum histomorphometry, and blood biochemistry of Cobb-500 broilers

Background and Aim

To combat enteric infections and antibiotic resistance in the poultry industry, researchers seek alternatives such as probiotics, prebiotics, and synbiotics as growth promoters. Synbiotics support probiotic growth through the supply of essential nutrients. The study's objectives were to assess the most effective delivery methods for synbiotics and evaluate their growth, histomorphometric, and hematological impacts on Cobb-500 broilers.

Materials and Methods

Two studies, independently conducted, employed a completely randomized design. One hundred and eighty viable eggs in the first trial were assigned to three groups: Control (T1), sterile water (T2), and synbiotic in sterile water (T3). On the 21st day of hatching, hatchability, day-old body weights, and ileum samples for histomorphometric analysis were recorded. In the second trial, out of 500 viable eggs, 200 eggs were fed in ovo with synbiotics (PoultryStar® sol, Biomin Singapore Pte Ltd, Singapore) on 17.5 days and 300 were set aside without in ovo injection. The treatments were control (T1), in water synbiotic (T2), in ovo synbiotic (T3), combination of in ovo synbiotic and synbiotic in feed (T4), and synbiotic in feed only (T5). On 21 and 42 days, blood, ileum, and visceral organ samples were collected for laboratory analysis. Data on weight gain, daily feed intake, and water consumption were recorded for 42 days.

Results

The initial experiment's results revealed a decrease in hatchability, slight weight increase, and significant intestinal morphological changes with the use of an in ovo synbiotic. Applying synbiotic through various methods in the second trial yielded better growth results, lower blood cholesterol, and significantly longer (p < 0.05) villi on 21 days.

Conclusion

Using the in ovo method to administer synbiotics lowered hatchability. Use of synbiotics with any method or in combination enhances growth, ileum structure, dressing yield, feed efficiency, and cholesterol levels in blood. Synbiotics enhance gut health and overall performance in broilers when used through diverse approaches.

Early intestinal development of chickens divergently selected for high or low 8-wk body weight and a commercial broiler

The early posthatch period is crucial to intestinal development, shaping long-term growth, metabolism, and health of the chick. The objective of this study was to determine the effect of genetic selection on morphological characteristics and gene expression during early intestinal development. Populations of White Plymouth Rocks have been selected for high weight (HWS) and low weight (LWS) for over 63 generations, and some LWS display symptoms of anorexia. Intestinal structure and function of these populations were compared to a commercial broiler Cobb 500 (Cobb) during the perihatch period. Egg weights, yolk-free embryo BW, yolk weights, and jejunal samples from HWS, LWS, and Cobb were collected on embryonic day (e) 17, e19, day of hatch, day (d) 3, d5, and d7 posthatch for histology and gene expression analysis. The RNAscope in-situ hybridization method was used to localize expression of the stem cell marker, olfactomedin 4 (Olfm4). Villus height (VH), crypt depth (CD), and VH/CD were measured from Olfm4 stained images using ImageJ. mRNA abundance for Olfm4, stem cell marker Lgr5, peptide transporter PepT1, goblet cell marker Muc2, marker of proliferation Ki67, and antimicrobial peptide LEAP2 were examined. Two-factor ANOVA was performed for measurements and Turkey's HSD was used for mean separation when appropriate. Cobb were heaviest and LWS the lightest (P < 0.01). at each timepoint. VH increased in Cobb and CD increased in HWS compared to LWS (P < 0.01). PepT1 mRNA was upregulated in LWS (P < 0.01), and Muc2 mRNA was decreased in both HWS and LWS compared to Cobb (P < 0.01). Selection for high or low 8-wk body weight has caused differences in intestinal gene expression and morphology when compared to a commercial broiler.

Prophybiotics for in-ovo stimulation; validation of effects on gut health and production of broiler chickens

Probiotics and phytobiotics have demonstrated effective improvement of gut health in broiler chickens when individually administered in-ovo. However, their combined use in-ovo, has not been studied to date. We coined the term "prophybiotic" (probiotic + phytobiotic) for such a combination. The current study therefore, aimed to elucidate the effects of combined use of a selected probiotic and a phytobiotic in-ovo, on broiler gut health and production parameters, as opposed to use of probiotics alone. ROSS 308 hatching eggs were injected with either Leuconostoc mesenteroides (probiotic: PB) or L. mesenteroides with garlic aqueous extract (prophyiotic: PPB) on the 12th day of incubation. Relative abundances of bacteria in feces and cecal content (qPCR), immune related gene expression in cecal mucosa (qPCR) and histomorphology of cecal tissue (PAS staining) were analyzed along with production parameters (hatch quality, body weight, feed efficiency and slaughter and meat quality). PPB treatment increased the abundance of faecalibacteria and bifidobacteria in feces (d 7) and Akkermansia sp. in cecal content. Moreover, it decreased Escherichia coli abundance in both feces (d 34) and cecal content. PB treatment only increased the faecalibacteria in feces (d 7) and Akkermansia sp. in the cecal content. Moreover, PPB treatment resulted in up-regulation of immune related genes (Avian beta defensing 1, Free fatty acid receptor 2 and Mucin 6) and increased the crypt depth in ceca whereas PB treatment demonstrated a higher crypt depth and a tendency to increase Mucin 6 gene expression. Both treatments did not impair the production parameters studied. In conclusion, our results suggest that in-ovo PPB treatment may have enhanced potential in boosting the immune system without compromising broiler production and efficiency, as compared to the use of probiotic alone. Our study, highlights the potential of carefully selected PPB combinations for better results in improving gut health of broiler chickens.

Effect of Lifelong Exposure to Dietary Plant and Marine Sources of n-3 Polyunsaturated Fatty Acids on Morphologic and Gene Expression Biomarkers of Intestinal Health in Early Life

Altered intestinal health is also associated with the incidence and severity of many chronic inflammatory conditions, which could be attenuated via dietary n-3 PUFA interventions. However, little is known about the effect of lifelong exposure to n-3 PUFA from plant and marine sources (beginning in utero via the maternal diet) on early life biomarkers of intestinal health. Harems of C57Bl/6 mice were randomly assigned to one of three isocaloric AIN-93G modified diets differing in their fat sources consisting of the following: (i) 10% safflower oil (SO, enriched in n-6 PUFA), (ii) 3% flaxseed oil + 7% safflower oil (FX, plant-based n-3 PUFA-enriched diet), or (iii) 3% menhaden fish oil + 7% safflower oil (MO, marine-based n-3 PUFA-enriched diet). Mothers remained on these diets throughout pregnancy and offspring (n = 14/diet) continued on the same parental diet until termination at 3 weeks of age. In ileum, villi:crypt length ratios were increased in both the FX and MO dietary groups compared to SO (p < 0.05). Ileum mRNA expression of critical intestinal health biomarkers was increased by both n-3 PUFA-enriched diets including Relmβ and REG3γ compared to SO (p < 0.05), whereas only the FX diet increased mRNA expression of TFF3 and Muc2 (p < 0.05) and only the MO diet increased mRNA expression of ZO-1 (p < 0.05). In the proximal colon, both the FX and MO diets increased crypt lengths compared to SO (p < 0.05), whereas only the MO diet increased goblet cell numbers compared to SO (p < 0.05). Further, the MO diet increased proximal colon mRNA expression of Relmβ and REG3γ (p < 0.05) and both MO and FX increased mRNA expression of Muc2 compared to SO (p < 0.05). Collectively, these results demonstrate that lifelong exposure to dietary n-3 PUFA, beginning in utero, from both plant and marine sources, can support intestinal health development in early life. The differential effects between plant and marine sources warrants further investigation for optimizing health.

Bacillus amyloliquefaciens Probiotics Mix Supplementation in a Broiler Leaky Gut Model

The supplementation of antimicrobial growth promoters (AGPs) has been banned in many countries because of the emergence of antimicrobial-resistant pathogens in poultry products and the environment. Probiotics have been broadly studied and demonstrated as a promising AGP substitute. Our study is centred on the effects of a multi-strain Bacillus-based probiotic product on broiler production performance and gut microbial profile in a dexamethasone-induced leaky gut challenge. Two hundred and fifty-six broiler chicks were hatched and randomly assigned into four groups (wheat-soybean meal basal diet (BD) = non-supplemented control (C), BD supplemented with dexamethasone in week 4 (CD), BD containing a probiotic from day one (P), and BD containing a probiotic from day one and supplemented with dexamethasone during challenge week 4 (PD)). The production performance and caecal, gizzard, jejunal lumen and jejunal mucosa swab microbiota were studied by 16S rRNA gene sequencing. The Bacillus probiotic product significantly improved production performance and altered caecal gut microbiota (p ≤ 0.05), but no significant impact on microbiota was observed in other gut sections.

Precision Glycan Supplementation Improves Gut Microbiota Diversity, Performance, and Disease Outbreak Resistance in Broiler Chickens

The poultry industry contributes significantly to the global meat industry but faces many production challenges like high-density housing, welfare issues, and pathogenic infections. While antibiotics have commonly been used to treat many of these issues, they are being removed from poultry production globally due to increased microbial resistance. Precision glycans offer a viable alternative to antibiotics by modulating microbial metabolic pathways. In this study, we investigated the effects of precision glycan supplementation on productivity and gut microbiota in broilers. The experiment was conducted in a commercial setting using 32,400 male Ross chickens randomly divided into three sheds with 10,800 birds each. One shed with 12 pen replicates of 900 birds was used as control, while the other two with an equal number of replicates and birds were assigned to precision glycan supplementation. The treatment significantly improved the average daily weight gain and feed conversion ratio, with a significant modification in the abundance of several bacterial taxa in the caecum, ileum, and ileum mucosa microbial communities. There was increased richness and diversity in the caecum, with a reduction in Proteobacteria and an increase in Firmicutes. Richness remained unchanged in the ileum, with an increase in diversity and reduction in pathogenic genera like Clostridium and Escherichia-Shigella. Ileum mucosa showed a lower abundance of mucin degraders and an increased presence of next-generation probiotics. Supplemented birds showed a high level of disease resistance when the farm experienced an outbreak of infectious bronchitis, evidenced by lower mortality. Histological analysis confirmed improvements in the ileum and liver health, where the precision glycan supplementation reduced the area of congested sinusoids compared to the control group in the liver and significantly improved ileum intestinal morphology by increasing crypt depth and surface area. These results collectively suggest that precision glycans offer substantial benefits in poultry production by improving productivity, gut health, and disease resistance.

Influence of a Commercial Synbiotic Administered In Ovo and In-Water on Broiler Chicken Performance and Meat Quality

The present study aimed to test the synbiotic PoultryStar^® sol^US delivered in ovo to evaluate its effect on hatchability, productive performance and meat quality, compared to its post-hatch administration in water. On the twelfth day of embryonic incubation, 1200 fertile eggs were divided into synbiotic groups injected with 2 mg/embryo (T1) and 3 mg/embryo (T2), a saline group injected with physiological saline and an uninjected control group (C). After hatching, 120 male chicks/group were reared and chicks from the saline group were supplemented with the synbiotic via drinking water (T3). Hatchability was low in both T1 and T2 groups. Growth performance was not affected by the treatments. However, in the second rearing phase (15-36 days), birds from the C and T3 groups were heavier than T1 birds, due to a higher feed intake and daily weight gain. Neither route of synbiotic administration influenced final body weight (at 56 days), weight and yield of the carcass or commercial cuts. Physico-chemical properties, total lipid, cholesterol and fatty acid composition of breast muscle were not affected by the treatments. Considering its exploratory nature, this study has raised many questions that need further investigation, such as the bioactive combination and the effect on embryonic development.

Administration of a Multi-Genus Synbiotic to Broilers: Effects on Gut Health, Microbial Composition and Performance

In recent years, the applicability of prebiotics, probiotics and their mixtures, defined as synbiotics, in poultry production has received considerable attention. Following the increasing regulation of antibiotic use, these nutraceuticals are seen as an alternative way to sustain production efficiency and resistance to pathogens and stressors by modulating birds' gut health. The aim of this study was to evaluate the benefits provided under field conditions by administering the multi-species synbiotic PoultryStar^® sol to broilers in drinking water. To this purpose, three Ross 308 broiler flocks, representing separate progenies of a breeder flock which was treated with the same synbiotic, were housed in separate farms, divided into treatment and control groups, and followed throughout the productive cycle. Synbiotic administration was shown to improve gut health even in absence of a challenge, with limited changes in terms of macroscopic intestinal lesions and more overt differences related to histopathological scores and villi length. Synbiotic-fed chickens performed consistently better in terms of body weight gain, feed conversion ratio and survivability. Lastly, the evaluation of the caecal microbiome through next-generation sequencing highlighted the effects of synbiotic supplementation on the composition of the bacterial population, the implications of which will, however, require further studies to be better comprehended.

Intraamniotic Administration (Gallus gallus) of Genistein Alters Mineral Transport, Intestinal Morphology, and Gut Microbiota

Genistein is an isoflavone naturally present in numerous staple food crops, such as soybeans and chickpeas. This study utilized the Gallus gallus intraamniotic administration procedure to assess genistein administration effects on trace mineral status, brush border membrane (BBM) functionality, intestinal morphology, and intestinal microbiome in vivo. Eggs were divided into five groups with 1 mL injection of the following treatments: no-injection, DI H₂O, 5% inulin, and 1.25% and 2.5% genistein (n = 8 per group). Upon hatch, blood, cecum, small intestine, and liver were collected for assessment of hemoglobin, intestinal microflora alterations, intestinal morphometric assessment, and mRNA gene expression of relevant iron and zinc transporter proteins, respectively. This study demonstrated that intraamniotic administration of 2.5% genistein increased villus surface area, number of acidic goblet cells, and hemoglobin. Additionally, genistein exposure downregulated duodenal cytochrome B (DcytB) and upregulated hepcidin expression. Further, genistein exposure positively altered the composition and function of the intestinal microbiota. Our results suggest a physiological role for genistein administration in improving mineral status, favorably altering BBM functionality and development, positively modulating the intestinal microbiome, as well as improving physiological status.

Effects of Probiotics, Prebiotics and Synbiotics Injected in Ovo on the Microstructure of the Breast Muscle in Different Chicken Genotypes

The aim of the study was to analyse the effect of probiotics, prebiotics and synbiotics injected in ovo on day 12 of embryonic development on the microstructure of the superficial pectoral muscle (musculus pectoralis superficialis) from 42-day-old chickens of different genotypes: broilers (Ross 308) and general-purpose type (green-legged partridge (GP) chickens Zk-11, native chickens). Incubated eggs were divided into four groups (each genotype separately) depending on the substance injected in ovo: normal saline (C, control); Lactococcus lactis subsp. cremoris (PRO); galactooligosaccharides, GOS (PRE) or GOS + L. lactis (SYN). After hatching, chicks were placed in eight replicated pens (four pens/genotype group). There were eight birds per pen. In total, 64 birds were used in the experiment. Birds were slaughtered at the age of 42 days, and samples of superficial pectoral muscles were taken for analysis. The microstructure of the pectoral muscles was evaluated using the cryosectioning (frozen tissue sectioning) technique and staining with haematoxylin and eosin. Statistical analysis revealed that the in ovo injection of probiotics, prebiotics and synbiotics had no significant effect on the diameter of muscle fibres from chickens of the two genotypes. The number of fibres in the muscles from green-legged partridge chickens was about three-fold higher than the fibre density in the muscles from broiler chickens, with the fibre diameter being two-fold smaller. This fact may indicate a greater tenderness of meat from GP chickens compared to the meat from Ross 308 broilers. In the case of broilers, a prebiotic (GOS) was the most effective bioactive substance in reducing the number of histopathological changes. Considering muscles from GP chickens, the number of normal fibres was highest in birds treated with the probiotic. These findings indicate that the microstructural features of pectoral muscles depend not only on the type of the injected bioactive substance but also on the genotype of chickens.

Chicken embryo as a model in epigenetic research

Epigenetics is defined as the study of changes in gene function that are mitotically or meiotically heritable and do not lead to a change in DNA sequence. Epigenetic modifications are important mechanisms that fine tune the expression of genes in response to extracellular signals and environmental changes. In vertebrates, crucial epigenetic reprogramming events occur during early embryogenesis and germ cell development. Chicken embryo, which develops external to the mother's body, can be easily manipulated in vivo and in vitro, and hence, it is an excellent model for performing epigenetic studies. Environmental factors such as temperature can affect the development of an embryo into the phenotype of an adult. A better understanding of the environmental impact on embryo development can be achieved by analyzing the direct effects of epigenetic modifications as well as their molecular background and their intergenerational and transgenerational inheritance. In this overview, the current possibility of epigenetic changes during chicken embryonic development and their effects on long-term postembryonic development are discussed.

The Effects of In Ovo Injection of Synbiotics on the Early Growth Performance and Intestinal Health of Chicks

In this study, the effects of synbiotic inclusion at the intra-amniotic stage in layer chicks were evaluated with different parameters, such as performance, immunological function, intestinal development, and cecal microflora content. A total of 1,200 eggs with fertile embryos were allocated into four treatment groups. For every treatment, five replicates were used, and 60 eggs were included in each replicate. The following four treatment groups were established: the non-injected group, 0.9% physiological saline injection (saline) group, 1 × 10⁶ CFU/egg Lactobacillus plantarum injection (probiotic) group, and 1 × 10⁶ CFU/egg L. plantarum + 2 mg/egg Astragalus polysaccharide injection (synbiotic) group. In ovo injection was carried out at 18.5 days of incubation. The results showed that in ovo injection of probiotics or synbiotics did not affect the hatching or growth performance of the chicks but significantly increased their feed intake (FI), body weight (BW), and the feed conversion ratio (FCR). Additionally, in ovo injection of synbiotics enhanced the levels of serum interleukin-2 (IL-2), interferon-γ (IFN-γ), and secretory immunoglobulin A (SIgA) in intestinal lavage fluid and the histomorphological development of the small intestine. Our results also indicated that intra-amniotic synbiotic injection significantly increased Lactobacillus and Bifidobacterium colonization while decreasing the relative abundance of Escherichia coli in the chicken cecum (P < 0.05). In summary, in ovo injection of synbiotics had positive impacts on the performance, immunological function, gut development, and microbiota of growing chicks.

Coenzyme Q10 attenuates inflammation and fibrosis implicated in radiation enteropathy through suppression of NF-kB/TGF-β/MMP-9 pathways

Radiation enteropathy is one the most common clinical issue for patients receiving radiotherapy for abdominal/pelvic tumors which severely affect the quality of life of cancer patients due to dysplastic lesions (ischemia, ulcer, or fibrosis) that aggravate the radiation damage. Herein, this study demonstrated the prophylactic role of coenzyme Q10 (CoQ10), a powerful antioxidant, against radiotherapy-induced gastrointestinal injury. Male Sprague Dawley rats were divided into four groups: group 1 was defined as control, and group 2 was the irradiated group. Group 3 and 4 were CoQ10 control and radiation plus CoQ10 groups, respectively. CoQ10 (10 mg/kg) was orally administered for 10 days before 10 Gy whole-body radiation and was continued for 4 days post-irradiation. CoQ10 administration protected rats delivered a lethal dose of ϒ-radiation from changes in crypt-villus structures and promoted regeneration of the intestinal epithelium. CoQ10 attenuated radiation-induced oxidative stress by decreasing lipid peroxidation and increasing the antioxidant enzyme catalase activity and reduced glutathione level. CoQ10 also counteracts inflammatory response mediated after radiation exposure through downregulating intestinal NF-ĸB expression which subsequently decreased the level of inflammatory cytokine IL-6 and the expression of COX-2. Radiation-induced intestinal fibrosis confirmed via Masson's trichrome staining occurred through upregulating transforming growth factor (TGF)-β1 and matrix metalloproteinase (MMP)-9 expression, while CoQ10 administration significantly diminishes these effects which further confirmed the anti-fibrotic property of CoQ10. Therefore, CoQ10 is a promising radioprotector that could prevent intestinal complications and enhance the therapeutic ratio of radiotherapy in patients with pelvic tumors through suppressing the NF-kB/TGF-β1/MMP-9 signaling pathway.

Chicken embryo development: metabolic and morphological basis for in ovo feeding technology

Broiler embryonic development depends on the nutrients that are available in the egg, which includes mostly water, lipids, and proteins. Carbohydrates represent less than 1%, and free glucose only 0.3%, of the total nutrients. Considering that energy requirements increase during incubation and metabolism is shifted toward the use of glycogen stores and gluconeogenesis from amino acids, extensive muscle protein degradation in the end of incubation can compromise chick development in the initial days after hatch. Significant prehatch changes occur in embryonic metabolism to parallel the rapid embryonic development. Oral consumption of the amniotic fluid begins around 17 d of incubation and promotes rapid development of the intestinal mucosa, which is characterized by morphological changes and increased expression and activity of enzymes and transporters. Furthermore, ingested substrates are stored as nutritional reserves to be used during hatching and in the first week after hatch. At hatch, this limited-nutrient store is directed to the functional development of the gastrointestinal tract to enable assimilation of exogenous nutrients. In ovo feeding is an alternative to deliver essential nutrients to chick embryos at this critical and challenging phase. The improved nutritional status and physiological changes triggered by in ovo feeding can resonate throughout the entire rearing period with significant health and economic gains. The present review addresses the main changes in metabolism and intestinal development throughout incubation, and also addresses scientific advances, limitations and future perspectives associated with the use of in ovo feeding that has been regarded as an important technology by the poultry industry.

Effects of a Trans-Galactooligosaccharide on Biochemical Blood Parameters and Intestine Morphometric Parameters of Common Carp (Cyprinus carpio L.)

Simple Summary

Prebiotics are important feed additives used in aquaculture. These are substances that are breeding grounds for beneficial bacteria and that inhibit the development of pathogens; accelerate healing and regeneration of the intestinal epithelium; increase mucus production; help maintain normal pH in the intestine; limit the growth of pathogenic bacteria; increase calcium, iron and magnesium absorption; and also have beneficial effects on glucose and protein metabolism in the liver. The saccharide-based prebiotic used in the carp experiment had a positive effect on intestine morphometric parameters. Supplementation of this prebiotic had no negative effect on growth performance and did not disturb the homeostasis of the fish, as demonstrated by the values of biochemical blood parameters.

Abstract

The aim of the study was to evaluate the effects of a trans-galactooligosaccharide prebiotic (GOS) on the growth performance, biochemical blood parameters, and intestine morphometric parameters of common carp. The 60-day-long experiment was performed on one-year-old fish with a mean body weight of 180 g (±5 g). Three diets were used: control diet 1 (C) with no microbiota affecting feed additives, diet 2 (B1) with 1% of prebiotic, and diet 3 (B2) with 2% of prebiotic, in four replications (tanks) per treatment and 25 fish per tank. At the end of the trial, 16 individuals from each group were used for analyses. The study showed that GOS supplementation did not affect growth performance. In turn, the prebiotic had a positive effect on the development of the intestine, and increased the height, width, and surface of the villi in B1 and B2 groups. The content of phosphorus (P) was significantly higher in B1 group compared with B2 group, which indicated that 1% addition of prebiotic causes better absorption of P from the intestine. The other biochemical indicators—namely lipid, protein and hepatic parameters, insulin, and Ca—were not affected by GOS treatment, which may indicate similar metabolic balance of fish in each experimental group. Serum triiodothyronine (TT₃) and glucose (stress markers) concentrations were not significantly different among treatments groups. GOS may be recommended as a feed additive for common carp due to its positive effects on fish physiology and development of the gastrointestinal tract. However, our results suggest that 1% diet supplementation causes satisfactory reactions for the abovementioned aspects in comparison to control or 2% supplementation.

Effects of in ovo injection of prebiotics and synbiotics on the productive performance and microstructural features of the superficial pectoral muscle in broiler chickens

The aim of the study was to compare the effects of 2 prebiotics and 2 synbiotics injected in ovo on productivity parameters, quality, and microstructure of the superficial pectoral muscle in 35-day-old broiler chickens. On day 12 of incubation, 9,000 eggs Ross 308 were randomly divided into 5 experimental groups treated with different bioactives in ovo injected: C, control with physiological saline; PI, with 1.760 mg inulin; PB, with 0.528 mg of commercial prebiotic Bi2tos; SI, with 1.760 mg inulin and 1,000 CFU Lactococcus lactis spp. lactis IBB SL1; SB, with 0.528 mg Bi2tos and 1,000 CFU Lactococcus lactis spp. cremoris IBB SC1. The synbiotic solution contained 20 μl bacterial suspension and 180 μl prebiotic solution. For productive parameters and further tests ten male birds for each experimental group were used. The birds were slaughtered on day 35 of age. At slaughter, samples of the left pectoral muscles were taken and preserved by freezing in liquid nitrogen. The pH and color of the meat were evaluated at 45 min and 24 h post-mortem. Water holding capacity (WHC) was measured and expressed as the percentage of free water in meat. Microscopic specimens were analysed using MultiScan software for the measurement of the percentage of oxidative and glycolytic fibres and mean diameter of the muscle fibres. In ovo injection of prebiotics Bi2tos had a positive effect on body weight. In prebiotic group (PI) a negative impact on hatchability was observed. Prebiotics and synbiotics had no influence on the yield of the carcass and pectoral muscle. Bioactive compounds had a significant effect on the quality of meat parameters such as: pH 24 h (PI and PB group), L* 45' (SI and SB group), and WHC (groups PB, SI, and SB). The analysis of the enzymatic profile showed a significant increase in the percentage of glycolytic fibres in the pectoral muscle from chicken treated with a synbiotic with the addition of inulin (group SI).

Protective effects and mechanisms of omega-3 polyunsaturated fatty acid on intestinal injury and macrophage polarization in peritoneal dialysis rats

AIM

This study was conducted to investigate the chronic injury of peritoneal glucose injection on the peritoneum and intestine and the protective effects of omega-3 polyunsaturated fatty acid (ω-3PUFA) during peritoneal dialysis (PD).

METHODS

Peritoneal dialysis animal models were established by intraperitoneal injection of 4.25% glucose for 28 days. Protein expression in ileum and peritoneum was measured by immunofloresence and immunohistochemistry. Protein expression in macrophages was measured by Western blot. Fibrosis was analyzed by Masson staining.

RESULTS

Peritoneal dialysis significantly increased the structural injury and decreased junction-related protein ZO-1 and occludin expression in ileum, the expression of proteins relating to the activation of M2 (Erg2, IRF4), but not M1 (CD38, IRF5) macrophages. PD significantly increased the expression of TGF-β1, VEGF and ALK5 protein in peritoneal tissues. PD significantly increased fibrosis (Masson staining) and the expression of fibroblast marker α-SMA in peritoneal tissues. Injection of macrophage clean reagent and ω-3PUFA significantly inhibited M2 activation, and decreased Masson staining, α-SMA, TGF-β1, VEGF and ALK5 protein expression in peritoneal tissues in PD treated rats. ω-3PUFA injection significantly decreased PD-induced injury in ileum and normalized the expression of ZO-1 and occludin in the ileum of PD rats.

CONCLUSION

Omega-3 fatty acids can provide a protective role on PD-induced peritoneal fibrosis and injury of the intestine.

Early Nutrition Programming (in ovo and Post-hatch Feeding) as a Strategy to Modulate Gut Health of Poultry

Healthy gastrointestinal tract (GIT) is crucial for optimum performance, better feed efficiency, and overall health of poultry. In the past, antibiotic growth promoters (AGP) were commonly used to modulate the gut health of animals. However, considering the public health concern, the use of AGP in animal feeding is banned or regulated in several jurisdictions around the world. This necessitates the need for alternative nutritional strategies to produce healthy poultry. For that, several alternatives to AGP have been attempted with some success. However, effective modulation of the gut health parameters depends on the methods and timing of the compound being available to host animals. Routinely, the alternatives to AGP and other nutrients are provided in feed or water to poultry. However, the GIT of the newly hatched poultry is functionally immature, despite going through significant morphological, cellular, and molecular changes toward the end of incubation. Thus, early growth and development of GIT are of critical importance to enhance nutrients utilization and optimize the growth of poultry. Early nutrition programming using both in ovo and post-hatch feeding has been used as a means to modulate the early growth and development of GIT and found to be an effective strategy but with inconsistent results. This review summarizes the information on in ovo and post-hatch-feeding of different nutrients and feeds additives and their effects on gut development, histomorphology, microbiology, and immunology. Furthermore, this review will provide insight on the future of early nutrition programming as a strategy to enhance gut health, thereby improving overall health and production so that the poultry industry can benefit from this technique.

Transcriptome modulation by in ovo delivered Lactobacillus synbiotics in a range of chicken tissues

Synbiotics are the bioactive compounds that synergistically combine effects of prebiotics and probiotics. In poultry, synbiotics can be used to reprogram animal's intestinal microbiota upon perinatal in ovo injection on day 12 of eggs incubation. Optimally composed synbiotic delivered in ovo efficiently stimulates the host's intestinal microflora, which in turn exerts beneficial effects on the host and improves its physiological functions. The aim of the study was to estimate long-term changes in the chicken transcriptome after a single in ovo administration of two different synbiotics. On day 12 of eggs incubation, 5850 eggs of broiler chicken were distributed to experimental groups and injected with synbiotic 1 (S1)- Lactobacillus salivarius with galactooligosaccharides (GOS) or synbiotic 2 (S2)- Lactobacillus plantarum with raffinose family oligosaccharides (RFO). On day 21 post-hatching cockerels were sacrificed and immunological (cecal tonsils and spleen), intestinal (jejunum) and metabolic (liver) tissues were collected (n = 5). Isolated RNA served as a template for the whole-transcriptome analysis using GeneChip Chicken Gene 1.1. ST Array Strip (Affymetrix). Data analysis was performed using Affymetrix Expression Console and Transcriptome Analysis Console software, Venn diagrams, DAVID and CateGOrizer. The highest number of Differentially Expressed Genes (DEG) was detected in cecal tonsils (160 DEG) after S1 in ovo injection, and in liver (159 DEG) after S2 injection. The influence of S1 on transcriptome modulation was demonstrated by a strong activation of the genes taking part in the pathways related to metabolism and immune response in cecal tonsils. S2 injection led to modulation of the gene expression associated with metabolic and developmental signaling pathways in the liver. Obtained results let us conclude that synbiotics delivered in ovo have significant impact on chicken transcriptome and their effect depends on the composition of the bioactive compound.

Modulation of microbial communities and mucosal gene expression in chicken intestines after galactooligosaccharides delivery In Ovo

Intestinal mucosa is the interface between the microbial content of the gut and the host's milieu. The goal of this study was to modulate chicken intestinal microflora by in ovo stimulation with galactooligosaccharides (GOS) prebiotic and to demonstrate the molecular responses of the host. The animal trial was performed on meat-type chickens (Ross 308). GOS was delivered by in ovo injection performed into the air cell on day 12 of egg incubation. Analysis of microbial communities and mucosal gene expression was performed at slaughter (day 42 post-hatching). Chyme (for DNA isolation) and intestinal mucosa (for RNA isolation) from four distinct intestinal segments (duodenum, jejunum, ileum, and caecum) was sampled. The relative abundance of Bifidobacterium spp. and Lactobacillus spp. in DNA isolated from chyme samples was determined using qPCR. On the host side, the mRNA expression of 13 genes grouped into two panels was analysed with RT-qPCR. Panel (1) included genes related to intestinal innate immune responses (IL-1β, IL-10 and IL-12p40, AvBD1 and CATHL2). Panel (2) contained genes involved in intestinal barrier function (MUC6, CLDN1 and TJAP1) and nutrients sensing (FFAR2 and FFAR4, GLUT1, GLUT2 and GLUT5). GOS increased the relative abundance of Bifidobacterium in caecum (from 1.3% to 3.9%). Distinct effects of GOS on gene expression were manifested in jejunum and caecum. Cytokine genes (IL-1β, IL-10 and IL-12p40) were up-regulated in the jejunum and caecum of the GOS-treated group. Host defence peptides (AvBD1 and CATHL2) were up-regulated in the caecum of the GOS-treated group. Free fatty acid receptors (FFAR2 and FFAR4) were up-regulated in all three compartments of the intestine (except the duodenum). Glucose transporters were down-regulated in duodenum (GLUT2 and GLUT5) but up-regulated in the hindgut (GLUT1 and GLUT2). In conclusion, GOS delivered in ovo had a bifidogenic effect in adult chickens. It also modulated gene expression related to intestinal immune responses, gut barrier function, and nutrient sensing.

Prebiotics and synbiotics - in ovo delivery for improved lifespan condition in chicken

Commercially produced chickens have become key food-producing animals in the global food system. The scale of production in industrial settings has changed management systems to a point now very far from traditional methods. During the perinatal period, newly hatched chicks undergo processing, vaccination and transportation, which introduces a gap in access to feed and water. This gap, referred to as the hatching window, dampens the potential for microflora inoculation and as such, prevents proper microbiome, gastrointestinal system and innate immunity development. As a consequence, the industrial production of chickens with a poor microbial profile leads to enteric microbial infestation and infectious disease outbreaks, which became even more prevalent after the withdrawal of antibiotic growth promoters on many world markets (e.g., the EU).This review presents the rationale, methodology and life-long effects of in ovo stimulation of chicken microflora. In ovo stimulation provides efficient embryonic microbiome colonization with commensal microflora during the perinatal period. A carefully selected bioactive formulation (prebiotics, probiotics alone or combined into synbiotics) is delivered into the air cell of the egg on day 12 of egg incubation. The prebiotic penetrates the outer and inner egg membranes and stimulates development on the innate microflora in the embryonic guts. Probiotics are available after the mechanical breakage of the shell membranes by the chick's beak at the beginning of hatching (day 19). The intestinal microflora after in ovo stimulation is potent enough for competitive exclusion and programs the lifespan condition. We present the effects of different combinations of prebiotic and probiotic delivered in ovo on day 12 of egg incubation on microflora, growth traits, feed efficiency, intestinal morphology, meat microstructure and quality, immune system development, physiological characteristics and the transcriptome of the broiler chickens.We discuss the differences between in ovo stimulation (day 12 of egg incubation) and in ovo feeding (days 17-18 of egg incubation) and speculate about possible future developments in this field. In summary, decades of research on in ovo stimulation and the lifelong effects support this method as efficient programming of lifespan conditions in commercially raised chickens.

Current Perspectives of the Chicken Gastrointestinal Tract and Its Microbiome

The microbial communities inhabiting the gastrointestinal tract (GIT) of chickens are essential for the gut homeostasis, the host metabolism and affect the animals' physiology and health. They play an important role in nutrient digestion, pathogen inhibition and interact with the gut-associated immune system. Throughout the last years high-throughput sequencing technologies have been used to analyze the bacterial communities that colonize the different sections of chickens' gut. The most common methodologies are targeted amplicon sequencing followed by metagenome shotgun sequencing as well as metaproteomics aiming at a broad range of topics such as dietary effects, animal diseases, bird performance and host genetics. However, the respective analyses are still at the beginning and currently there is a lack of information in regard to the activity and functional characterization of the gut microbial communities. In the future, the use of multi-omics approaches may enhance research related to chicken production, animal and also public health. Furthermore, combinations with other disciplines such as genomics, immunology and physiology may have the potential to elucidate the definition of a "healthy" gut microbiota.