Pre- and posthatch development of goblet cells in the broiler small intestine: effect of delayed access to feed

Effect of Putrescine Inoculation In Ovo on Hatchability, Hepatic and Muscular Glycogen Reserve, Intestinal Morphology, and Performance of Broilers

The objective of this study was to evaluate the inoculation of nutrient solutions with increasing levels of putrescine on the hatchability, physiology, and performance of broilers during the initial phase. The study is composed of four treatments with increasing doses of putrescine (0.015; 0.030; 0.060, and 0.090%) and a control group. At hatch, hatchability rate; ratio between egg weight and chick weight; ratio between yolk sac, liver, breast and intestine weight, and chick weight; glycogen concentration in the liver and breast; and morphometric characteristics of the jejunum and ileum were evaluated. After hatch, 400 birds were housed in metabolic cages according to the treatments received, and feed intake, body weight gain, and feed conversion ratio were assessed at specific time points. Hatchability, chick performance at hatch, and organ weight were not affected by the inoculation of increasing levels of putrescine. Intestinal villi at hatch were higher in groups supplemented with putrescine (p < 0.001). The amounts of hepatic glycogen per gram of tissue at hatch were higher in groups with the lowest levels of putrescine and decreased with increasing doses (p = 0.017). Growth performance from 1 to 21 days was not influenced by the inoculation of putrescine.

Effects of in-ovo injection of Yu ping feng polysaccharides on growth performance, intestinal development, and immunity in broiler chickens

This study aimed to investigate the effects of the in-ovo injection of Yu Ping Feng polysaccharides (YPF) on the immunological development, hatchability, growth performance, intestinal tissue development, intestinal IgA+ cell distribution, and intestinal secretory IgA (SIgA) production in broiler chicken. Herein, 800 chicken embryos were randomly divided into Astragalus polysaccharide (APS), Atractylodes macrocephala polysaccharide (ATR), YPF, and normal saline (control) injection groups-polysaccharide injection, 0.5 mL of 4 mg/mL polysaccharide; normal saline injection, 0.5 mL. The related indexes of hatched chicks were detected, and there were 5 repeats in each group. Compared with the other three groups, the in-ovo YPF injection did not affect the hatching rate of chicken embryos; however, the initial body weight of hatchlings significantly increased and the feed conversion ratio decreased. Additionally, at each time point, the intestinal villus height (VH) of the chicks in the YPF group increased, whereas no notable difference was observed in the crypt depth (CD), resulting in a higher VH/CD ratio. Furthermore, the YPF group exhibited a statistically significant increase in intestinal IgA+ cell count and flushing fluid SIgA level throughout various time periods compared with those in the other three groups. Additionally, the expression of intestinal mucosal immune cytokines, including interleukin (IL)-2, IL-4, IL-6, and interferon-γ, were markedly increased in the duodenum and ileum of the YPF group. Moreover, the analysis of immune development revealed that their serum levels in the polysaccharide-injected groups were also increased, with the YPF groups exhibiting superior performance than the APS and ATR groups and encouraging the development of T and B lymphocytes in the spleen and peripheral blood mononuclear cells. Altogether, the findings of this study demonstrate that the in-ovo injection of YPF can improve the growth performance, intestinal tissue development, and immune system of the broiler chicks.

Descriptive embryological insights of the colorectum of quail embryos with concern to its functional morphology

BACKGROUND

Quail is an interesting emerging bird species gaining attention in developmental embryology research due to its small size, quick lifespan, and fast growth rate. These characteristics make quail an ideal model for examining the development of the gastrointestinal tract. Consequently, the embryonic development of the colorectum was conducted to provide a comprehensive understanding of its functions in digestion, absorption, and immunity.

METHODOLOGY

The morphological anatomy and microscopical structure of the colorectal wall of 74 embryos were studied using light and scanning electron microscopy (SEM). Histologically, the embryos were collected and dissected to extract the intestine. The samples were then fixed in 10% neutral buffer formalin for a minimum of 24 h, and in 2.5% glutaraldehyde buffer formalin for semithin processing and scanning electron microscopy.

RESULTS

The wall of the embryonic colorectum on the hatching day consisted of three layers; mucosa, muscularis externa, and serosa. Mucosa was a simple layer of columnar enterocytes interspersed with goblet cells that appeared as cub-like shaped cells. Additionally, two ganglionic plexuses were also developed in the colorectal wall; Auerbach plexus (among the colorectal tunica muscularis) and Meissner plexus (submucosal plexus).

CONCLUSION

The morphological characteristics of the quail colorectum at different ages were closely related to its functional features.

Evaluation the effect of dietary vitamin E, sesamin and thymoquinone bioactive compounds on immunological response, intestinal traits and MUC-2 gene expression in broiler Japanese quails (Coturnix japonica)

The current study was performed to determine the effect of dietary vitamin E, sesamin and thymoquinone bioactive lignans derived from sesame and black seed on immunological response, intestinal traits and Mucin2 gene expression in broiler quails. Three hundred and fifty (one days-old) quails were allotted to seven dietary treatments with five replicates as an experimental randomized design study. Treatments were basal diet as a control, control +100 and +200 mg of vitamin E, sesamin and thymoquinone per each kg of diet respectively. At 35 d of age, two quails from each pen were chosen, weighted, slaughtered, eviscerated and lymphoid organ relative weights were measured. Anti-body titers against Newcastle disease (ND), Sheep red blood cell (SRBC), and infectious bronchitis virus (IBV) and Avian influenza (AI) vaccination were determined. The serum activities of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and serum antioxidant activates such as superoxide dismutase (SOD),glutathione peroxidase(GPX), catalase (CAT) and total antioxidant capacity (TAC) were examined. The cell mediated immunity by dinitrochlorobenzene (DNCB) and phytohemagglutinin (PHA) challenges were assessed. The microflora populations of ileum, morphological traits of jejunum and mucin2 gene expression were analyzed. Data showed that the lymphoid organ (thymus, spleen and Bursa) relative weights and antibody titer against HI, AI, SRBC and IB vaccination were increased compared to the control (p ≤ 0.05). Serum activities of ALP, ALT and AST were decreased under influences of dietary treatments (p ≤ 0.05). The serum antioxidant activates of GPX,SOD,CAT and TAC were increased and Increasing in mean skin thickness after DNCB challenge and decrease wing web swelling response to PHA mitojen injection were observed (p ≤ 0.05). Salmonella enterica, E-coli and Coliforms colonies were decrease and Lactobacillus colonies increased instead (p ≤ 0.05). The villus height and surface, crypt depth and goblet cells density were increased compared to the control (p ≤ 0.05). The expression of MUC2 gene increased under influnces of vitamin E, sesamin and thymoquinone supplemented diets (p ≤ 0.05).

Optimising Growth, Immunity, and Gene Expression in Broiler Chickens Through Dietary Threonine Levels and Oil Inclusion

BACKGROUND

The inclusion of synthetic amino acids in poultry nutrition plays a crucial role in both enhancing the synthesis of immunoglobulins and elevating the overall comprehensiveness of the amino acid profile.

OBJECTIVES

This research examined the effects of consuming threonine (Thr) in various forms levels with low or high oil on broiler chickens' growth and immunity.

METHODS

We investigate the growth performance, feed efficiency, immune response, intestinal morphology, absorptive capacity, and expression of some genes related to the feed intake (Pro-opiomelanocortin [POMC]), fatty acid synthesis (Acetyl-CoA Carboxylase [ACC]), immunity (lipopolysaccharide-induced tumour necrosis like alpha factor [LITAF]), and heat shock protein 70 (HSP70). Eight groups of chicks were used, including four dietary Thr levels (100%, 115%, 130%, or 145%) with two oil levels (mixture of sunflower 50% and soybean oils 50%): (control) and high.

RESULTS

The higher dietary Thr level (145%) with high oil inclusion significantly increased ACC and POMC gene expression, resulting in the lowest feed intake, body weight gain (BWG), and liver fat content. Combining high oil with 115% Thr was the optimum for the broilers. The birds have significant (p ≤ .05) growth performance, immune parameters, and intestinal health, as well as the lowest expression of ACC, POMC, HSP70, and LITAF, which was reflected in better feed conversion ratio and lower incidence of fatty liver, thermo-resistance, and immune status of the birds.

CONCLUSIONS

The combination of high oil and 115% Thr levels optimises broiler health and productivity, enhancing growth, immune function, and gut health. This diet lowers the expression of genes associated with fatty liver and stress, leading to better feed efficiency, thermo-resistance, and overall well-being. Adopting these dietary adjustments can improve broiler performance and economic viability in poultry farming by enhancing essential productivity metrics.

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.

Supply organ development of young broilers in response to increased carbohydrates and amino acids in the starter period

The growth of broiler chickens is marked by high fluctuations, varying nutrient requirement, early growth is characterized by high allometric growth rates of supply organs, which if underdeveloped, can impede nutrient efficiency and growth of demand organs like muscle and skeleton. This study aimed to investigate the impact of carbohydrate- and amino-acid-rich diets on the development of supply organs in broiler chickens. Four dietary treatments were used in a 2 × 2 factorial arrangement of treatments with apparent metabolizable energy (AME) at 2 levels (low: 2,750 kcal/kg and high: 3,050 kcal/kg) and standardized ileal digestible (SID) lysine at 2 levels (low: 1.0% and high: 1.2%) in the starter diets. Feed intake (FI) and BW gain were measured weekly; dissections were conducted at d 4 and d 11 to determine supply organ weights. Allometric growth of the liver was higher (P < 0.001) in the high AME and low lysine group compared to the other groups. For the pancreas, the highest (P < 0.001) allometric growth rate was in the high lysine groups. The small intestines responded differently; the duodenum had the highest (P < 0.001) allometric growth rate in the high AME groups and the jejunum in the low lysine groups, whereas the ileum showed an effect of diet density. For performance, high AME from carbohydrates, via maize starch, had a negative effect (P < 0.001) on FI and BW gain. High lysine had a positive effect (P < 0.001) on BW gain and FI, and high lysine alleviated part of the detrimental effect of high AME from carbohydrates. This effect was visible from d 0 to d 11, and persisted till the end of the trial on d 35. In conclusion, feeding a diet with a high AME from carbohydrates has negative consequences for the development of the supply organs of broilers.

Integrating Multi-Omics Data to Identify Key Functional Variants Affecting Feed Efficiency in Large White Boars

Optimizing feed efficiency through the feed conversion ratio (FCR) is paramount for economic viability and sustainability. In this study, we integrated RNA-seq, ATAC-seq, and genome-wide association study (GWAS) data to investigate key functional variants associated with feed efficiency in pigs. Identification of differentially expressed genes in the duodenal and muscle tissues of low- and high-FCR pigs revealed that pathways related to digestion of dietary carbohydrate are responsible for differences in feed efficiency between individuals. Differential open chromatin regions identified by ATAC-seq were linked to genes involved in glycolytic and fatty acid processes. GWAS identified 211 significant single-nucleotide polymorphisms associated with feed efficiency traits, with candidate genes PPP1R14C, TH, and CTSD. Integration of duodenal ATAC-seq data and GWAS data identified six key functional variants, particularly in the 1500985-1509676 region on chromosome 2. In those regions, CTSD was found to be highly expressed in the duodenal tissues of pigs with a high feed conversion ratio, suggesting its role as a potential target gene. Overall, the integration of multi-omics data provided insights into the genetic basis of feed efficiency, offering valuable information for breeding more efficient pig breeds.

Methionine sources and genotype affect embryonic intestinal development, antioxidants, tight junctions, and growth-related gene expression in chickens

Methionine (Met) is an essential and first limiting amino acid in the poultry diet that plays a significant role in chicken embryonic development and growth. The present study examined the effect of in ovo injection of DL-Met and L-Met sources and genotypes on chicken embryonic-intestinal development and health. Fertilized eggs of the two genotypes, TETRA-SL layer hybrid (TSL) - commercial layer hybrid and Hungarian Partridge colored hen breed (HPC) - a native genotype, were randomly distributed into four treatments for each genotype. The treatment groups include the following: 1) control non-injected eggs (NoIn); 2) saline-injected (SaIn); 3) DL-Met injected (DLM); and 4) L-Met injected (LM). The in ovo injection was carried out on 17.5 d of embryonic development; after hatching, eight chicks per group were sacrificed, and the jejunum was extracted for analysis. The results showed that both DLM and LM groups had enhanced intestinal development as evidenced by increased villus width, villus height, and villus area (P < 0.05) compared to the control. The DLM group had significantly reduced crypt depth, glutathione content (GSH), glutathione S-transferase 3 alpha (GST3), occludin (OCLN) gene expression and increased villus height to crypt depth ratio in the TSL genotype than the LM group (P < 0.05). The HPC genotype has overexpressed insulin-like growth factor 1 (IGF1) gene, tricellulin (MD2), occludin (OCLN), superoxide dismutase 1 (SOD1), and GST3 genes than the TSL genotype (P < 0.05). In conclusion, these findings showed that in ovo injection of Met enhanced intestinal development, and function, with genotypes responding differently under normal conditions. Genotypes also influenced the expression of intestinal antioxidants, tight junction, and growth-related genes.

Histological and histochemical characteristics of the developing chicken (Gallus gallus domesticus) cecum

Avian ceca play an important role in liquid absorption, cellulose digestion, and defensive mechanism. This study aims to demonstrate histological and histochemical characteristics of developing chicken cecum. For this purpose, 10 embryos on the 18th day of incubation, 10 chicks on hatching day and 10 chicks on the seventh day post-hatching were used. The histological sections prepared from proximal, middle, and distal parts of cecum were stained with Crossmon's triple stain, periodic-acid Schiff, Alcian blue (pH 2.5), Masson-Fontana's argentaffin silver stain and Gordon and Sweets's silver stain. Alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACP-ase) were also demonstrated in the sections. In the proximal part, although the villi were rudimentary on the 18th day of incubation, well-developed villi were seen at seventh day post-hatching. In middle and distal parts, while it was seen that rudimentary folds appeared on the 18th day of incubation, mucosal folds were prominent and short villi were formed on the hatching day and seventh day post-hatching. Goblet cells and enteroendocrine cells were detected from the 18th day of incubation. The lymphoid follicles supported with reticular fibres were seen on the seventh day post-hatching in proximal cecum wall. While ACP-ase (+) lymphocytes were rarely observed, more ANAE (+) lymphocytes were in lymphoid follicles. As a result, development of cecum in chickens has been demonstrated by histological techniques in this study.

Influence of Different Light Spectra on Melatonin Synthesis by the Pineal Gland and Influence on the Immune System in Chickens

It is well known that the pineal gland in birds influences behavioural and physiological functions, including those of the immune system. The purpose of this research is to examine the endocrine-immune correlations between melatonin and immune system activity. Through a description of the immune-pineal axis, we formulated the objective to determine and describe: the development of the pineal gland; how light influences secretory activity; and how melatonin influences the activity of primary and secondary lymphoid organs. The pineal gland has the ability to turn light information into an endocrine signal suitable for the immune system via the membrane receptors Mel1a, Mel1b, and Mel1c, as well as the nuclear receptors RORα, RORβ, and RORγ. We can state the following findings: green monochromatic light (560 nm) increased serum melatonin levels and promoted a stronger humoral and cellular immune response by proliferating B and T lymphocytes; the combination of green and blue monochromatic light (560-480 nm) ameliorated the inflammatory response and protected lymphoid organs from oxidative stress; and red monochromatic light (660 nm) maintained the inflammatory response and promoted the growth of pathogenic bacteria. Melatonin can be considered a potent antioxidant and immunomodulator and is a critical element in the coordination between external light stimulation and the body's internal response.

Goloba kusi (Hornstedtia scottiana [F. Muell.] K. Schum.) fruit as a feed additive to improve the histological structures and growth performance of broiler

Background and Aim: The broiler farming industry in Indonesia has enormous potential, with chicken meat that can be optimized by providing adequate and high-quality feed. However, the main raw material for the feed still relies on imported products, which makes it necessary to produce alternative materials from native plants. Therefore, this study aimed to investigate the effect of giving Goloba kusi fruit (GF) (Hornstedtia scottiana [F. Muell.] K. Schum.) on the growth of the small intestine, pectoralis major, and gastrocnemius muscle, as well as the development of broiler chickens. Materials and Methods: This study used a completely randomized design, in which 300 day-old Chicks were divided into five groups, consisting of 12 chickens in each group with five replications. The GF treatments, namely, 0% (control [CON]), 0.625% (GF1), 1.25% (GF2), 2.5% (GF3), and 5% (GF4) were administered through per kg basal feed. Subsequently, three chickens from each replication were taken, decapitated on the neck, subjected to surgery for histological preparations, and stained with Hematoxylin-Eosin and Periodic acid-Schiff-alcian blue. The variables observed included small intestine morphology, muscle morphology, and chicken growth performance. Results: The results showed that the small intestine morphology, muscle morphology, and chicken growth performance of the GF4 (5%) group increased significantly compared to the CON group. Conclusion: The administration of GF with an optimum concentration of 5% through basal feed improves small intestine morphology, muscle morphology, and chicken growth performance.

Effect of the Addition of Humic Substances on Morphometric Analysis and Number of Goblet Cells in the Intestinal Mucosa of Broiler Chickens

The mechanisms of action of humic substances (HS) as growth promoters in poultry are unknown. In this study, the productive performance, histology, and number of goblet cells (GC) in the intestinal villi of broilers under steady-state digestive conditions and under abrupt changes in diet with the addition of HS was evaluated. Broilers housed individually were offered three treatments from 14−28 days: 1 = diet with white corn/soybean meal, without growth promoter antibiotics (nonGPA); 2 = with GPA (GPA); and 3 = with 0.3% HS. At day 28, two diets were suddenly introduced: (A) white corn/soybean meal plus dried distillers’ grains with solubles (DDGS); and (B) white/blue corn/soybean meal/DDGS, keeping the three original treatments. Diets A and B were also exchanged on day 37. FCR was lower with GPA and HS compared to nonGPA from 14−38 days (p < 0.05); at day 28, under steady-state digestive conditions, HS had a similar effect to GPA on the histology and GC number in the jejunum villi. The number of GC in the jejunum of HS-fed broilers on days 29 and 38, after diet changes, behaves similarly to that of AGP-fed broilers (p > 0.05). HS appears to strengthen the mucosal protection of the epithelium of the intestine.

Anatomical, histochemical, and immunohistochemical observations on the gastrointestinal tract of Gallinula chloropus (Aves: Rallidae)

Background

Gallinula chloropus (Linnaeus, 1758) is a wild aquatic omnivorous bird characterized by a marked resistance to harsh environmental conditions and a worldwide distribution. In this study, anatomical, morphometrical, histochemical, and immunohistochemical techniques were employed to study the structure of the gastrointestinal tract of Gallinula chloropus.

Results

The esophagus appeared tubular with no distinct crop. Both superficial (SPG) and deep (DPG) proventricular glands were present. The DPG filled about two-thirds of the total wall thickness. Histochemically, the mucosubstances revealed mixed alcian blue-PAS positive reactions. They were mainly localized in the acini of the esophageal glands and SPG, gastric surface epithelium, duct system of DPG, and intestinal goblet cells. The highest number of goblet cells per every 1 mm2 of the intestinal mucosa was seen within the ileum and rectum, 2555 ± 468 and 2607 ± 653 respectively. Notably, glucagon immunoreactive (IR) cells were abundant in the mucosa of the small and large intestines and the proventriculus, while somatostatin IR cells were concentrated within the acini of the DPG. IR cells for the mitosis marker phospho-histone H3 (PHH3) were highest within the entire intestinal crypts and mucosa-associated lymphoid tissues (MALT). In contrast, cells IR for the apoptosis marker C.CASP3 were remarkable in epithelial cells at the tips of intestinal villi and in MALT, reflecting the dynamic nature of the latter mentioned structures.

Conclusions

The findings of the present study advance our knowledge of the gross and microscopic anatomy of the gastrointestinal tract in wild birds and could help to enhance the productivity of Aves via improving gut health.

Low inclusion levels of Tenebrio molitor larvae meal in laying Japanese quail (Coturnix japonica, Gould, 1837) diet improve the intestinal morphometry, enzymatic activity and caecal short chain fatty acids profile

One hundred twenty, 12 weeks old laying Japanese quails (JQ) were equally divided into 4 groups (6 replicates of 5 birds/group). The control group (CON) fed a corn-soybean diet; TML1.4, TML2.8, and TML5.6 groups fed a diet where a Tenebrio molitor larvae meal (TML) was included at 1.4, 2.8, and 5.6%, respectively. The trial lasted 54 days. The villi height (VH) and the crypt depth (CD) linearly decreased from the control to the TML5.6 group (P < 0.01) in the duodenum, while an opposite trend was observed for the Ab+ mucous cells count (P < 0.01). The highest VH/CD ratio was found in the TML1.4 group (P < 0.01). In the jejunum a lower VH was observed in the TML1.4 compared to the CON group; the Ab+ mucous cells increased (P < 0.01) according to the increase of the TM inclusion in the diet, while the highest VH/CD ratio (P < 0.01) was recorded in the TML2.8 group. In the duodenum only the L-ANP has been affected by TML (P < 0.001), with a quadratic and linear effect. The L-ANP is affected by the dietary treatment in the jejunum (P < 0.05), where showed a quadratic effect with the highest value in TML2.8. The % of butyric acid is maximized (P < 0.05) with the TML1.4 diet and that of the isobutyrate and valeric acids increased (P < 0.01) from TML1.4 to TML5.6. The use of TML at 1.4% in laying quail diets can be considered as a way to improve the intestinal health of the birds.

Performance and gut health status of broilers fed diets supplemented with two graded levels of a monoglyceride blend

The present study was undertaken to evaluate the efficacy of 2 graded levels (0.03 and 0.05% of diet) of a monoglyceride blend containing butyric, caprylic, and capric acids in broilers' diet for optimizing gut structure and animal growth performance. For this purpose, a total of 210, one-day-old male Ross 308 broiler chicks were randomly allocated to 3 experimental treatments using 7 replicates each and 10 birds/replicate. The treatment groups involved supplementation of blend of short and medium chain fatty acids at the level of 0, 0.03, and 0.05% of the diet for 42 d. The incorporation of mixes of monoglycerides into broilers' diet linearly improved BWG between d 0 and 21 (P = 0.034). At the end of trial, however, no significant changes were observed in performance indexes (BWG, FI, FCR). Jejunal morphometric parameters (villus height, crypt depth, and their ratio) remained unaltered with the monoglyceride supplementation on d 21. The results further showed that monoglycerides supplementation increased the goblet cell counts along the jejunal villi (P = 0.034) and crypt regions (P = 0.022), as well as it effectively modulated the mRNA abundances of tight junction protein (ZO-1, P = 0.033) and nutrient transporters (SGLT, PePT1; P = 0.005, 0.023, respectively) in the jejunum. Moreover, the downregulation in mRNA abundance of TNFα (P = 0.030) was observed with the monoglyceride supplementation. The SCFAs analysis of cecal contents showed no notable differences with monoglyceride blend supplementation when compared to the unsupplemented group. Collectively, high goblet cell numbers in the jejunum along with downregulation of the mRNA abundances of pro-inflammatory cytokines, upregulation of tight junction proteins, and nutrient transporters showed favorable responses of low doses of monoglycerides blend in broiler feeding. Further studies should be conducted in different rearing conditions to examine the effectiveness of such low levels of a monoglyceride blend in the modulation of gut structure, its functionality and animal performance.

Development of small intestine and sugar absorptive capacity in goslings during pre- and post-hatching periods

This study was conducted to investigate the development patterns of small intestine, intestinal morphology, disaccharidase activities, and sugar transporter gene expression in goslings during pre- and post-hatching periods. Small intestine was sampled on embryonic d 23 and 27, day of hatch, and d 1, 4, and 7 post-hatching. A total of 18 eggs with the breed of Jilin White geese were selected at each sampling timepoint for measuring relevant parameters. Three eggs were considered as a group, with 6 groups in each sampling timepoint. Rapid development of small intestine was observed around the hatching, of which jejunum and ileum had relatively higher development rates. Villus surface area from three intestinal segments started to increase on embryonic d 27, and kept relatively stable during day of hatch to d 1 post-hatching, and following increased till d 7 post-hatching. A high priority of villi enrichment was observed in duodenum and jejunum. The activity of disaccharidase increased before hatching and kept relatively high-level post-hatching, of which the activity of disaccharidase was highest in jejunum. The expression of sugar transporter gene increased prior to hatching and then decreased post-hatching, of which jejunum and duodenum were sites with high sugar transporter gene expression. Rapid development in intestinal morphology, disaccharidase activities, and sugar transporter gene expression around the hatching indicated that goslings have high potential to digest and/or assimilate carbohydrates during its early-life, which provided a preparation for further digestion of exogenous feed. This study provided a profile of development patterns for intestinal morphology, disaccharidase activities, and sugar transporter gene expression in goslings, which was beneficial to understanding the characteristics of nutrient absorption during the early-life of goslings.

Influence of coliform bacteria infection on intestinal goblet cells secretory activity of germ-free piglets

Recently, influence of bacteria colonization on development and maturation of gut wall is getting more into the focus of gastrointestinal research. For years, the main interest and research were aimed to the development and maturation of gut wall and its functional properties in normal conditions, less attention has been paid on the germ-free animals. Germ-free (GF) piglets have clear microbiological background and are reared in sterile environment. GF piglets are regarded as clinically relevant models for studying of human diseases, as these piglets’ manifest similar clinical symptoms to humans. In this study we briefly summarised the main characteristics in the distribution of goblet cells in the wall of jejunum and colon of GF piglets as healthy control (HC) group and piglets, which were experimentally infected by E. coli O149:K88 as ECK group. Neutral mucins were stained with periodic acid-Shiff (PAS) whereas acidic mucins are stained with Alcian blue. Numbers of goblet cells containing total acidic mucins in both, the jejunum and colon, differed significantly between HC and ECK piglets and in the colon, a similar trend was also observed. In the ECK piglets, jejunal goblet cells exhibited decrease in neutral mucins. This change in mucin profile in response to bacterial colonization suggests a potential role as a protective mechanism against pathogenic invasion of the intestinal mucosa during of gut mucosa development in piglets.

Tracking the developmental events in the duodenum of the quail embryo: Using light and electron microscope

The present study described the full morphology of the duodenum of the Japanese quail during the embryonic stage from 3rd day of incubation till hatching using the light and electron (scanning and transmission) microscope. The specimens were collected, analyzed and described anatomically, morphometrically and microscopically. The first recognition of the prospective duodenum was at the 4th day of incubation and developed continuously by age progression. The prospective duodenum consisted of a flat pseudostratified epithelium, mesenchyme and covering mesothelium. On day 8th of incubation, the epithelium developed three evaginations lead to formation three previllous ridges protruding inside the duodenal lumen, which later at the 9th day differentiated into numbers of projections; villi. On the 9th day, the epithelium lined the villi transformed into a simple columnar type, the duodenal villi appeared as pyramidal-shaped projections, had wide base and narrow apex and by age progression, the duodenal villi went through changes in number, size and shape. On hatching day, the duodenal epithelium consisted of enterocytes interspersed with secretory goblet cells, which stained positive for both Periodic Acid Schiff (PAS) and Alcian blue AB and represented filled with metachromatic granules. The muscular wall started as mesenchymal condensation on the 6th day then differentiated into the circular smooth muscle layer on the 9th day of incubation. Giving detailed information about the morphological development of the duodenum during the incubation period of quail embryo helps in reaching a satisfactory explanation about how the duodenum plays a vital role in digestion, absorption and immunity.

Nutritional stimulation by in-ovo feeding modulates cellular proliferation and differentiation in the small intestinal epithelium of chicks

Nutritional stimulation of the developing small intestine of chick embryos can be conducted by in-ovo feeding (IOF). We hypothesized that IOF of glutamine and leucine can enhance small intestinal development by promoting proliferation and differentiation of multipotent small intestinal epithelial cells. Broiler embryos (n = 128) were subject to IOF of glutamine (IOF-Gln), leucine (IOF-Leu), NaCl (IOF-NaCl) or no injection (control) at embryonic d 17 (E 17). Multipotent, progenitor and differentiated cells were located and quantified in the small intestinal epithelium between E 17 and d 7 after hatch (D 7) in all treatment groups by immunofluorescence of SRY-box transcription factor 9 (Sox9) and proliferating cell nuclear antigen (PCNA), in-situ hybridization of leucine-rich repeat containing G-protein coupled receptor 5 (Lgr5) and peptide transporter 1 (PepT1) and histochemical goblet cell staining. The effects of IOF treatments at E 19 (48 h post-IOF), in comparison to control embryos, were as follows: total cell counts increased by 40%, 33% and 19%, and multipotent cell counts increased by 52%, 50% and 38%, in IOF-Gln, IOF-Leu and IOF-NaCl embryos, respectively. Only IOF-Gln embryos exhibited a significance, 36% increase in progenitor cell counts. All IOF treatments shifted Lgr5+ stem cell localizations to villus bottoms. The differentiated, PepT1+ region of the villi was 1.9 and 1.3-fold longer in IOF-Gln and IOF-Leu embryos, respectively, while goblet cell densities decreased by 20% in IOF-Gln embryos. Post–hatch, crypt and villi epithelial cell counts were significantly higher IOF-Gln chicks, compared to control chicks (P < 0.05). We conclude IOF of glutamine stimulates small intestinal maturation and functionality during the peri-hatch period by promoting multipotent cell proliferation and differentiation, resulting in enhanced compartmentalization of multipotent and differentiated cell niches and expansions of the absorptive surface area.

Phytogenic Compounds for Enhancing Intestinal Barrier Function in Poultry-A Review

After the European Union ban of antibiotic growth promoters, works on different methods of improving gut health have intensified. The poultry industry is struggling with problems that were previously controlled by antibiotic growth promoters, therefore the search for optimal solutions continues. Simultaneously, there is also increasing social pressure to minimize the use of antibiotics and replace them with alternative feed additives. A variety of available alternatives is considered safe by consumers, among which phytogenics play a significant role. However, there are still some limitations that need to be considered. The most questionable are the issues related to bioavailability, metabolism of plant derivatives in birds, and the difficulty of standardizing commercial products. There is still a need for more evidence-based recommendations for the use of phytogenics in livestock. On the other hand, a positive influence of phytogenic compounds on the health of poultry has been previously described by many researchers and practical application of these compounds has auspicious perspectives in poultry production. Supplementation with phytogenic feed additives has been shown to protect birds from various environmental threats leading to impaired intestinal barrier function. Phytogenic feed additives have the potential to improve the overall structure of intestinal mucosa as well as gut barrier function on a molecular level. Recognition of the phytogenics' effect on the components of the intestinal barrier may enable the selection of the most suitable ones to alleviate negative effects of different agents. This review aims to summarize current knowledge of the influence of various phytogenic constituents on the intestinal barrier and health of poultry.

Light and transmission electron microscopic evaluation of the lamina epithelialis mucosae in the ileum of pre- and post-hatch broiler chicken

Morphological development of the lamina epithelialis mucosae (LEM) of the ileum of broiler chicken was evaluated using light and transmission electron microscopic techniques. Ileal sections were collected on embryonic days (ED) 14, 17 and 19, as well as post-hatch days (PD) 1, 3, 5, 7, 14, 21, 28, 35, 42 and 56. The result showed that the ileal LEM, which were poorly defined at embryonic days 14 and 17, consisted of enterocytes and some atypically shaped goblet cells. Apico-lateral tight junctions and irregularly shaped microvilli were associated with the enterocytes at ED 14 and 17. The enterocyte microvilli were more uniform in shape and distribution at ED 19. The embryonic goblet cells were varied in shape and possessed basally displaced, star-shaped nuclei and small apical cytoplasmic vacuoles. During the post-hatch ages, the LEM was a typical epithelium with a single layer of columnar-shaped enterocytes that became highly elongated at post-hatch day (PD) 7. The goblet cells were characteristically 'wine-glass' shaped. Follicle-associated epithelium (FAE) showing numerous lymphocytes among the enterocytes occurred in the post-hatch LEM. The intra-epithelial lymphocytes (IEL) were first encountered at PD 1, but increased several folds within the first two weeks post-hatch. Entero-endocrine cells were observed in the epithelium from PD 21. Finally, from this study, it is obvious that enterocytes and small atypically shaped goblet cells occur in the ileal LEM during the pre-hatch period, but these cells assume adult morphological characteristics after hatch. Thus, the cells of the ileal LEM play strategic absorptive, secretory and protective roles in the gut.

Managing Gut Microbiota through In Ovo Nutrition Influences Early-Life Programming in Broiler Chickens

The chicken gut is the habitat to trillions of microorganisms that affect physiological functions and immune status through metabolic activities and host interaction. Gut microbiota research previously focused on inflammation; however, it is now clear that these microbial communities play an essential role in maintaining normal homeostatic conditions by regulating the immune system. In addition, the microbiota helps reduce and prevent pathogen colonization of the gut via the mechanism of competitive exclusion and the synthesis of bactericidal molecules. Under commercial conditions, newly hatched chicks have access to feed after 36-72 h of hatching due to the hatch window and routine hatchery practices. This delay adversely affects the potential inoculation of the healthy microbiota and impairs the development and maturation of muscle, the immune system, and the gastrointestinal tract (GIT). Modulating the gut microbiota has been proposed as a potential strategy for improving host health and productivity and avoiding undesirable effects on gut health and the immune system. Using early-life programming via in ovo stimulation with probiotics and prebiotics, it may be possible to avoid selected metabolic disorders, poor immunity, and pathogen resistance, which the broiler industry now faces due to commercial hatching and selection pressures imposed by an increasingly demanding market.

The Interplay between Salmonella and Intestinal Innate Immune Cells in Chickens

Salmonellosis is a common infection in poultry, which results in huge economic losses in the poultry industry. At the same time, Salmonella infections are a threat to public health, since contaminated poultry products can lead to zoonotic infections. Antibiotics as feed additives have proven to be an effective prophylactic option to control Salmonella infections, but due to resistance issues in humans and animals, the use of antimicrobials in food animals has been banned in Europe. Hence, there is an urgent need to look for alternative strategies that can protect poultry against Salmonella infections. One such alternative could be to strengthen the innate immune system in young chickens in order to prevent early life infections. This can be achieved by administration of immune modulating molecules that target innate immune cells, for example via feed, or by in-ovo applications. We aimed to review the innate immune system in the chicken intestine; the main site of Salmonella entrance, and its responsiveness to Salmonella infection. Identifying the most important players in the innate immune response in the intestine is a first step in designing targeted approaches for immune modulation.

Evaluating the effects of a dietary synbiotic or synbiotic plus enhanced organic acid on broiler performance and cecal and carcass Salmonella load

Several feed additives such as synbiotics and organic acids may be viable options for controlling Salmonella in poultry. This experiment was conducted to study the effects of synbiotic product or synbiotic plus enhanced organic acid program on broiler performance, intestinal histomorphology, and cecal and carcass Salmonella load. A total of 648 day-of-hatch Cobb 700 male broiler chicks were randomly allocated to one of 4 dietary treatments: basal control diet (CON), CON diet supplemented with a synbiotic (PoultryStar; 500 g/MT; PS), CON diet supplemented with PS in the starter phase and enhanced organic acid (Biotronic PX Top3 US; 500g/MT; BPX) in the grower and finisher phase (PS1+BPX2), and the CON diet supplemented with PS in the starter and grower phase and BPX in the finisher phase (PS2+BPX1). No differences in overall BW or BWG (P > 0.05) were observed among PS, PS1+BPX2, and PS2+BPX1; however, BW was consistently greater (P < 0.05) in PS, PS1+BPX2, and PS2+BPX1 compared with CON on d 14 28, 35, and 42. On d 1 to 14 and d 1 to 28, PS and PS2+BPX1 improved FCR compared to CON (P < 0.05); PS1+BPX2 had intermediate results. No differences (P > 0.05) in overall FI were observed among dietary treatments, although PS1+BP2 and PS2+BPX1 increased FI numerically compared to CON and PS. Both PS1+BPX2 and PS2+BPX1 had reduced carcass Salmonella load by 1.6 and 1.4 log units, respectively, compared with CON (P < 0.05); PS had intermediate results. Birds fed PS1+BPX2 and PS2+BPX1 reduced the percentage of postchilled carcasses that tested positive for Salmonella by 72% and 57%, respectively, compared to CON, while PS had intermediate results with a 43% reduction. This experiment demonstrated that dietary supplementation with synbiotic or synbiotic plus organic acid can be used as a potential tool to improve growth performance and reduce carcass Salmonella in broilers.

Development and Functional Properties of Intestinal Mucus Layer in Poultry

Intestinal mucus plays important roles in protecting the epithelial surfaces against pathogens, supporting the colonization with commensal bacteria, maintaining an appropriate environment for digestion, as well as facilitating nutrient transport from the lumen to the underlying epithelium. The mucus layer in the poultry gut is produced and preserved by mucin-secreting goblet cells that rapidly develop and mature after hatch as a response to external stimuli including environmental factors, intestinal microbiota as well as dietary factors. The ontogenetic development of goblet cells affects the mucin composition and secretion, causing an alteration in the physicochemical properties of the mucus layer. The intestinal mucus prevents the invasion of pathogens to the epithelium by its antibacterial properties (e.g. β-defensin, lysozyme, avidin and IgA) and creates a physical barrier with the ability to protect the epithelium from pathogens. Mucosal barrier is the first line of innate defense in the gastrointestinal tract. This barrier has a selective permeability that allows small particles and nutrients passing through. The structural components and functional properties of mucins have been reviewed extensively in humans and rodents, but it seems to be neglected in poultry. This review discusses the impact of age on development of goblet cells and their mucus production with relevance for the functional characteristics of mucus layer and its protective mechanism in the chicken’s intestine. Dietary factors directly and indirectly (through modification of the gut bacteria and their metabolic activities) affect goblet cell proliferation and differentiation and can be used to manipulate mucosal integrity and dynamic. However, the mode of action and mechanisms behind these effects need to be studied further. As mucins resist to digestion processes, the sloughed mucins can be utilized by bacteria in the lower part of the gut and are considered as endogenous loss of protein and energy to animal. Hydrothermal processing of poultry feed may reduce this loss by reduction in mucus shedding into the lumen. Given the significance of this loss and the lack of precise data, this matter needs to be carefully investigated in the future and the nutritional strategies reducing this loss have to be defined better.

Histological alterations of small intestine and growth performance of broiler chicks after in ovo copper injection at 10 days of embryogenesis period

This study aimed to assess impacts of early in ovo injection (at 10 days of incubation) of copper (sulfate, acetate, or nanoparticles) on histomorphometric parameters of small intestine and growth performance of post-hatched chicks. Fertile eggs (n = 462) were distributed to seven groups (3 replicates, 22 eggs in each). The first group as a control, the 2nd, 3rd and 4th groups injected with 100 µL deionized water containing 8 μg/egg of Cu (sulfate, acetate and nanoparticles, respectively), and the 5th, 6th and 7th groups injected with 100 µL deionized water containing 16 μg/egg of the same Cu sources above. Results illustrated that in ovo administration of Cu sulfate and Cu acetate significantly improved histological parameters of small intestine parts of newly hatched chicks compared with the control. Cu sulfate and nano-Cu significantly augmented body weight gain compared with the control. In ovo Cu injection showed a nonsignificant improvement in feed conversion ratio. The highest level (16 μg/egg) of different sources was better than the lowest level (8 μg/egg) in most results. In conclusion, it is recommended that in ovo injection of Cu (16 μg/egg) can improve the growth performance (Cu sulfate and nano-Cu) and the small intestine histomorphometry parameters (Cu sulfate and Cu acetate) of broiler chicks.

Histology of the small intestine in the common pheasant (Phasianus colchicus): A scanning electron microscopy, histochemical, immunohistochemical, and stereological study

The present investigation was conducted to investigate the histology, immunohistochemistry, stereology, and ultrastructure of the small intestine in the common pheasant (Phasianus colchicus) using light and scanning electron microscopy (SEM). Ten birds were included in the study. The obtained findings revealed that three parts in the small intestine namely duodenum, jejunum, and ilium constituted of four layers from innermost to outermost including tunica mucosa, tunica submucosa, tunica muscularis, and tunica serosa. All parts of the small intestine had simple columnar epithelium with goblet cells reacted with Periodic Acid-Schiff and Alcian Blue stains especially in the jejunum and ileum. The cells on the tip of the duodenal villi showed immuno-positive staining for Sox9 protein, while the jejunum and ileum were negative. The jejunum had longest villi; however the duodenum had deepest crypt (p < .05). The villus surface of jejunum was significantly higher than duodenum and ileum (p < .05). SEM images revealed that the duodenum had cauliflower and leaf-like villi with plicas and recess between them. Jejunum had finger-like villi with a velvety view. The shape of the ileal villi was like that observed in the jejunum with slight differences. In conclusion, the jejunum was the most prominent region in the small intestine in terms of morphologic and morphometric features, which could be attributed to the absorption of more nutrients in this area. These obtained findings would be useful to improve the knowledge in the field of histophysiology properties of the bird's digestive system.

The effect of delayed feeding post-hatch on caeca development in broiler chickens

1. Broiler chicks are frequently deprived of food up to 72 h due to uneven hatching rates, management procedures and transportation to farms. Little is known about the effect of delayed feeding due to extended hatching times on the early neonatal development of the caeca. Therefore, the objective of this study was to investigate the developmental changes and effects of a 48-h delay in feed access immediately post-hatch (PH) on the caeca.2. After hatch, birds (Ross 708) were randomly divided into two treatment groups (n = 6 battery pen/treatment). One group (early fed; EF) received feed and water immediately after hatch, while the second group (late fed; LF) had access to water but had delayed access to feed for 48 h. Contents averaging across all regions of the caeca were collected for mRNA expression as well as for histological analysis at -48, 0, 4 h PH and then at 1, 2, 3, 4, 6, 8, 10, 12 and 14 days PH.3. Expression of MCT-1 (a nutrient transporter), Cox7A2 (related to mitochondrial function) IgA, pIgR, and ChIL-8 (immune function) genes was affected by delayed access to feed that was dependent by the time PH. Expression of immune and gut barrier function-related genes (LEAP2 and MUC2, respectively) was increased in LF group. There was no effect of feed delay on expression of genes related to mitochondrial functions in the caeca, although developmental changes were observed (ATP5F1B, Cox4|1). Caecal mucus and muscle thickness were affected by delayed access to feed during caeca development.4. The data suggested a limited effect of delayed feed access PH on the developmental changes in caecal functions. However, the caeca seemed to be relatively resistant to delayed access to feed early PH, with only a few genes affected.

Effect of vitamin E and alpha lipoic acid on intestinal development associated with wooden breast myopathy in broilers

Intestinal development is closely associated with inflammatory wooden breast (WB) myopathy. Vitamin E (VE) and alpha lipoic acid (ALA) with antioxidant and anti-inflammatory effects were used independently and in combination to evaluate their effects on intestinal developmental changes in ileal morphology and expression of genes related with gut nutrient transport, structure, and inflammation in broilers during the first 3 wk posthatch. A total of 160 newly hatched Ross 708 broiler chicks were randomly assigned into a control and 3 dietary treatments with 10 replicates of 4 birds each. Supplementation of VE (160 mg/kg) and ALA (500 mg/kg) independently and in combination were fed during the first 3 wk. At 1, 2, and 3 wk of age, one chick from each pen was harvested. Plasma VE concentration and ileal morphology were determined. Gene expression was measured by real-time quantitative PCR. Broilers in VE and combination of ALA and VE group had higher plasma VE concentration than the control and ALA group at 1, 2, and 3 wk of age (P < 0.01). All dietary treatments increased ileal villus height at 1 wk of age (P < 0.01) and decreased intraepithelial lymphocytes at 3 wk of age compared to the control (P ≤ 0.05). Combination of VE and ALA increased collagen type IV alpha 1 chain expression (P ≤ 0.05) and improved basement membrane structure indicating increased gut basement membrane integrity at 2 and 3 wk of age compared to the control. Expression of lipopolysaccharide-induced tumor necrosis factor-alpha factor associated with inflammation was decreased in all dietary treatments at 3 wk of age compared to the control (P < 0.01). Ileal morphology and gene expression were closely correlated with breast muscle morphology and gene expression. These results suggest that VE and ALA especially when they were combined in the diet had positive effects on mitigating intestinal inflammation and improving nutrient transport beginning at 1 wk of age, which is likely critical in reducing the severity of WB.

Age-related histochemical investigations of small intestinal goblet cells in bronze turkeys (Meleagris gallopavo gallopavo)

The aim of the study was to investigate the goblet cell types and their density in the small intestine of bronze turkey (Meleagris meleagris gallopovo), by means of Alcian blue-PAS staining. Sixty birds from 10 age groups were used. In the duodenum and jejunum, goblet cells produced acid, neutral and mixed mucins, while in the jejunum - acid mucins. A negative relationship was observed between cell density and either duodenum or jejunum lengths; such a correlation was not established in the ileum.

Supplementation of vitamin E and omega-3 fatty acids during the early posthatch period on intestinal morphology and gene expression differentiation in broilers

Early posthatch nutrition is important for gut health. Vitamin E (VE) and omega-3 (n-3) fatty acids can improve gut health through antioxidative and anti-inflammatory effects. The objective of this study was to identify the effects of VE, n-3 fatty acids, and combination of both during the starter phase (0–10 d) or grower phase (11–24 d) on intestinal morphology and expression of genes associated with gut health. A total of 210 Ross 708 broilers were randomly assigned into 7 treatments with 10 replicates of 3 birds each. The control group was fed a corn–soybean meal–basal diet during the entire study (0–58 d). Supplementation of VE (200 IU/kg), n-3 fatty acids (n-6/n-3 ratio of 3.2:1), and combination of both were fed during the starter phase (0–10 d) or grower phase (11–24 d). All of the broilers were harvested at 58 d of age. Villus height, crypt depth, villus width, distance between villi, and number of intraepithelial lymphocytes were obtained. Expression of 21 genes was measured using NanoString analysis. Expression of solute carrier family 15 member 1 (P = 0.01) associated with peptide transport and mucin 2 (P = 0.03) related with intestinal mucus barrier was increased in the broilers supplemented with n-3 fatty acids in the grower diet compared with the control. Expression of solute carrier family 7 member 1 associated with amino acid transport was decreased in the group supplemented with n-3 fatty acids during the starter phase compared with the group supplemented with n-3 fatty acids (P = 0.01) or VE and n-3 fatty acids during the grower phase (P = 0.03). These data suggest that VE and n-3 fatty acids supplemented during the grower phase have a positive effect on improving nutrient transport with n-3 fatty acids supplementation in the grower diet showing the most beneficial effect. These findings can be used in the development of nutritional management strategies to improve broiler growth performance and meat quality.

It's All About Timing: Early Feeding Promotes Intestinal Maturation by Shifting the Ratios of Specialized Epithelial Cells in Chicks

The small intestine (SI) of chicks (Gallus gallus) matures rapidly during the initial post-hatch period and acquires digestive, absorptive, and secretive capabilities. The effects of the timing of first feeding on the quantities and distribution of specialized epithelial cells, which generate and maintain SI morphology and functionality, have not yet been examined. In this study, we identified specialized SI epithelial cell sub-types, including stem, progenitor, proliferating, and differentiated cells within crypts and villi of chicks during the first 10 days post-hatch, by in situ hybridization (ISH), immunofluorescence (IF), and histochemical staining. We then examined their quantities and ratios between day of hatch and d10 in chicks that were fed upon hatch [early feeding (EF)], compared to chicks that were fed 24 h post-hatch [delayed feeding (DF)]. Results showed that EF increased total cell quantities in the crypts and villi at days 1, 3, 7, and 10, compared to DF (p < 0.0001). At d3, EF, in comparison to DF, decreased crypt stem cell proportions (p < 0.0001), increased crypt proliferating (p < 0.01) and differentiated (p < 0.05) cell proportions, and increased villus enterocyte proportions (p < 0.01). By d10, EF increased both the quantities and proportions of villus enterocytes and goblet cells, compared to DF. We conclude that feeding upon hatch, compared to 24 h-delayed feeding, enhanced SI maturation and functionality by increasing the quantities and proportions of proliferating and differentiated cells, thus expanding the digestive, absorptive, and secretive cell populations throughout the initial post-hatch period.

Early Life Inoculation With Adult-Derived Microbiota Accelerates Maturation of Intestinal Microbiota and Enhances NK Cell Activation in Broiler Chickens

Studies in mammals, including chickens, have shown that the development of the immune system is affected by interactions with intestinal microbiota. Early life microbial colonization may affect the development of innate and adaptive immunity and may contribute to lasting effects on health and resilience of broiler chickens. We inoculated broiler chickens with adult-derived-microbiota (AM) to investigate their effects on intestinal microbiota composition and natural killer (NK) cells, amongst other immune cells. We hypothesized that AM inoculation directly upon hatch (day 0) would induce an alteration in microbiota composition shortly after hatch, and subsequently affect (subsets of) intestinal NK cells and their activation. Microbiota composition of caecal and ileal content of chickens of 1, 3, 7, 14, 21, and 35 days of age was assessed by sequencing of 16S ribosomal RNA gene amplicons. In parallel, subsets and activation of intestinal NK cells were analyzed by flow cytometry. In caecal content of 1- and 3-day-old AM chickens, a higher alpha-diversity (Faith's phylogenetic diversity) was observed compared to control chickens, whereas ileal microbiota were unaffected. Regarding beta-diversity, caecal microbiota profiles could be clustered into three distinct community types. Cluster A represented caecal microbiota of 1-day-old AM chickens and 1- and 3-day-old control chickens. Cluster B included microbiota of seven of eight 3- and 7-day-old AM and 7-day-old control chickens, and cluster C comprised microbiota of all chickens of 14-days and older, independent of inoculation. In 3-day-old AM chickens an increase in the percentages of intestinal IL-2Rα+NK cells and activated NK cells was observed compared to control chickens of the same age. In addition, an increase in relative numbers of intestinal cytotoxic CD8αα+T cells was observed in 14- and 21-day-old AM chickens. Taken together, these results indicate that early exposure to AM shapes and accelerates the maturation of caecal microbiota, which is paralleled by an increase in IL-2Rα+NK cells and enhanced NK cell activation. The observed association between early life development of intestinal microbiota and immune system indicates possibilities to apply microbiota-targeted strategies that can accelerate maturation of intestinal microbiota and strengthen the immune system, thereby improving the health and resilience of broiler chickens.

Bacillus subtilis RZ001 improves intestinal integrity and alleviates colitis by inhibiting the Notch signalling pathway and activating ATOH-1

Intestinal mucosal barriers help the body resist many intestinal inflammatory diseases, such as inflammatory bowel disease (IBD). In this study, we identified a novel bacterium promoting the repair of intestinal mucosa and investigated the potential mechanisms underlying its activity. Culture supernatant of Bacillus subtilis RZ001 upregulated the expression of mucin 2 (MUC2) and tight junction (TJ) proteins in HT-29 cells in vitro. Oral administration of B. subtilis RZ001 may have significantly reduced symptoms such as the dextran sulfate sodium (DSS)-induced decrease in body weight, shortening of colon length and overproduction of proinflammatory factors. The number of goblet cells and levels of MUC2 and TJ proteins were significantly increased in adult mice fed with B. subtilis RZ001. B. subtilis RZ001 cells upregulated the levels of MUC2 in the intestinal organoids. Furthermore, culture supernatant of B. subtilis RZ001 could suppress the Notch signalling pathway and activate the expression of atonal homolog 1 (Atoh1). The transcription factor Atoh1 is required for intestinal secretory cell differentiation and activates transcription of MUC2 via binding to E-boxes on the MUC2 promoter. Taken together, B. subtilis strain RZ001 has the potential for treating IBD. The present study is helpful to elucidate the mechanisms of B. subtilis action.

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.

Effect of delayed feeding post-hatch on expression of tight junction- and gut barrier-related genes in the small intestine of broiler chickens during neonatal development

The gut not only plays a key role in digestion and absorption of nutrients but also forms a physical barrier and first line of defense between the host and the luminal environment. A functional gut barrier (mucus and epithelial cells with tight junctions [TJ]) is essential for optimal health and efficient production in poultry. In current broiler system, chicks are deprived of food and water up to 72 h due to uneven hatching, hatchery procedures, and transportation. Post-hatch feed delay results in lower BW, higher FCR and mortality, and delayed post-hatch gut development. Little is known about the effects of early neonatal development and delayed feeding immediately post-hatch on gut barrier function in chickens. Therefore, the aim of the present study was to characterize the expression pattern of gut barrier-related and TJ-related genes in the small intestine of broiler chickens during early development and delay in access to feed. Newly hatched chicks received feed and water immediately after hatch or were subjected to 48 h delayed access to feed to mimic commercial hatchery setting and operations. Birds were sampled (n = 6) at -48, 0, 4, 24, 48, 72, 96, 144, 192, 240, 288, and 336 h post-hatch. Jejunum and ileum were collected, cleaned of digesta, and snap-frozen in liquid nitrogen or fixed in paraformaldehyde. The relative mRNA levels of gut barrier- and TJ-related protein genes were measured by quantitative PCR and analyzed by 2-way ANOVA. In both tissues, changes (P < 0.05) in gene expression pattern of gut barrier-related and TJ-related genes were detected due to delayed access to feed post-hatch and/or development. In general, expression of TJ-related genes was downregulated while mRNA levels of gut barrier-related genes were upregulated during development. Histological differences and changes in mucin staining due to age and treatment were observed. These results suggest that delayed access to feed post-hatch may affect TJ structure and/or function and therefore gut barrier function and overall health of the chicken small intestine.

Effects of putrescine injection in broiler breeder eggs

The aim of this study was to evaluate the effects of increasing doses of putrescine injected in ovo on hatchability, intestinal morphology and pre-starter performance of broilers. For this purpose, 720 eggs from broiler breeders were separated into a negative control (no injection) and injection treatments with increasing doses of putrescine (0.05; 0.1; 0.15 and 0.2%), totalling five treatments of 144 eggs each. Eggs were distributed in a completely randomized design inside the setter and the injection of solutions occurred at 17 days of incubation. After hatch, 330 birds were housed in mixed lots following the original treatments, totalling 5 treatments of 6 replicates with 11 birds each. Six birds per treatment were weighed and euthanized by cervical dislocation to collect the liver, intestine and breast 24 hr after injection, at hatch and 24 hr after hatch. At 2 days of age, intestines were collected from 4 animals per treatment to analyse histomorphology. The effects of putrescine levels were evaluated by polynomial regression models, ANOVA and Tukey test at 5% probability. The hatchability decreased linearly in response to increased doses of putrescine. The percentage of residual yolk was lower in animals that received putrescine compared to the control. After injection, the percentage of breast increased linearly, and the percentage of intestine had a quadratic response to increased doses of putrescine. However, 24 hr after hatch, the percentage of intestine linearly decreased, and the percentage of liver linearly increased in response to increased doses of putrescine. Villus height increased quadratically, crypt depth decreased linearly, and goblet cells increased linearly in response to the putrescine dose. FI and BWG were not affected in the pre-starter phase; however, FCR increased in response to increased levels of putrescine. Due to putrescine effects on embryos, it is recommended that the doses injected in ovo not exceed 0.1%.

Intestinal epithelium integrity after delayed onset of nutrition in broiler chickens

Fasting older broiler chickens (>7 d of age) enlarges the intestinal tight junction (TJ) pore size, resulting in high paracellular intestinal permeability. Broiler chickens often do not receive feed and water (nutrition) directly after hatch, which may result in fasting up to 72 h of age. Whether perinatal fasting affects intestinal permeability is minimally studied. We therefore investigated whether delayed access to nutrition after hatch increases intestinal permeability, compared with broilers receiving early access to nutrition. Therefore, 432 hatched broilers received nutrition 72 h after hatch (delayed nutrition [DN]) or directly after hatch (early nutrition [EN]) and were reared under similar conditions until 14 d of age. Two hours after application of an oral pulse dose (3.85 mg) of fluorescein isothiocyanate-dextran (4000 Da) at 4, 10, and 14 d of age, blood plasma concentrations of the marker were measured in 24 to 36 broilers per treatment and time point. Marker concentration in plasma did not differ between DN and EN broilers at any age. The villus width measured in at least 8 broilers per treatment was smaller in DN than in EN broilers at 4 d for both the ileum (92 ± 3 μm vs. 121 ± 4; P < 0.001) and colon (100 ± 3 vs. 120 ± 4; P < 0.01). Real-time quantitative PCR revealed that the expression of TJ protein claudin 3 in the ceca was elevated in DN, compared with EN broilers at 4 d of age, whereas that of zonula occludens 1 in the ileum was reduced. Expression of host defense-related genes was reduced in DN, compared with EN broilers, in the ileum (cyclo-oxygenase 2, mucin 2) and ceca (interleukin 1β, cyclo-oxygenase 2). We conclude that 72-hour DN reduced the BW up to 14 d of age, coinciding with transient effects on the villus width in the ileum and colon, and divergent expression of genes involved in TJ formation and host defense. These effects likely reflect the delayed onset of intestinal and immune development in DN, compared with EN broilers, while DN does not fundamentally alter intestinal permeability.

Delayed access to feed affects broiler small intestinal morphology and goblet cell ontogeny

Broilers are often deprived of feed and water for up to 48 h after hatch. This delayed access to feed (DAF) can inhibit small intestine development. The objective of this study was to determine the effects of DAF on small intestinal morphology, mRNA abundance of the goblet cell marker Muc2 and absorptive cell marker PepT1, and the distribution of goblet cells in young broilers. Cobb 500 chicks, hatching within a 12-h window, were randomly allocated into 3 groups: control with no feed delay (ND), 24-h feed delay (DAF24), and 36-h feed delay (DAF36). Morphology, gene expression, and in situ hybridization analyses were conducted on the duodenum, jejunum, and ileum at 0, 24, 36, 72, 120, and 168 h after hatch. Statistical analysis was performed using a t test for ND and DAF24 at 24 h. A 2-way ANOVA and Tukey's HSD test (P < 0.05) were used for ND, DAF24, and DAF36 from 36 h. At 24 to 36 h, DAF decreased the ratio of villus height/crypt depth (VH/CD) in the duodenum but increased VH/CD in the ileum due to changes in CD, whereas at 72 h, DAF decreased VH/CD due to a decrease in VH. The mRNA abundance of PepT1 was upregulated, while Muc2 mRNA was downregulated in DAF chicks. Cells expressing Muc2 mRNA were present along the villi and in the crypts. The ratio of the number of goblet cells found in the upper half to the lower half of the villus was greater in DAF chicks than in ND chicks, suggesting that DAF affected the appearance of new goblet cells. The number of Muc2 mRNA-expressing cells in the crypt, however, was generally not affected by DAF. In conclusion, DAF transiently affected small intestinal morphology, upregulated PepT1 mRNA, downregulated Muc2 mRNA, and changed the distribution of goblet cells in the villi. By 168 h, however, these parameters were not different between ND, DAF24, and DAF36 chicks.

Duodenal Histomorphological Changes in Broilers Administered poly d, l-lactic-coglycolic acid (PLGA ) Nanoparticles Encapsulated with Peptide

This research was carried out to evaluate the effect of poly d, l-lactic-coglycolic acid(PLGA) nanoparticles loaded with peptide (as vaccine) on histomorphological in duodenum of broiler chick. A total of ninety eight, one day old ,unsexed broiler( Rose) chicks were divided randomly into seven groups( 2 replicate in each group) as follows:G1-control,G2 - chicks received traditional vaccine of infectious bursal disease(Volvac@ IBD MLV) ,G3 – Chicks Received PLGA nanoparticles only, G4,G5,G6 and G7 – chicks were received prepared vaccine at 160, 80, 40,and 20 μg of peptide loaded PLGA respectively. At the end of the experiment histopathological examination of duodenum section and histomorphological changes were examined. The histopathological examination of duodenal sections shows an elongation and infiltration of lamina propria (LP) with increase villi height and crypt depth in groups that received PLGA alone and those received peptide loaded PLGA. At the same time these groups reveal an increase in mucosal thickness and in length and width of villi. The histomorphological examination in this study show thicker mucosal layer with deeper crypt in duodenum of broilers that subjected to PLGA administration alone or to different concentration of peptide loaded PLGA compared to G1 and G2. These findings are accompanied by a high density of goblet cells and lower villus hight/crypt depth (V/CD) ratio. All groups show mononuclear cells (MNCs) infiltration in submucosa ofduodenum. In-conclusion, the administration of PLGA nanoparticles is strongly linked to the improvement of the physiological and immunological features of the birds.

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens

The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1-14, 14-28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.

Identification, tissue characterization, and innate immune role of Angiogenin-4 expression in young broiler chickens

Intestinal epithelial cells are major producers of antimicrobial proteins, which play an important role in innate immunity. In addition to defensins, the Ribonuclease A superfamily includes important antimicrobial proteins involved in host-defense mechanisms in vertebrates. Angiogenin-4 (Ang4), a member of this RNase superfamily, has been demonstrated to be secreted by Paneth cells in mice. We have successfully cloned and characterized a new chicken gene (chAng4), found for the first time in a nonmammalian species, from intestinal epithelial and lymphoid cells. Characterization of chAng4 revealed 99% nucleotide and 97% amino acid sequence homology to mouse Ang4. Similar functional regions were identified, suggesting a role in innate immunity and regulation of gut microbiota. Furthermore, the mRNA expression pattern of chAng4 was studied in broilers in the presence or absence of beneficial bacteria (probiotics) and organic acids. The results showed that one-day-old chickens expressed low levels of Ang4 in almost all the evaluated tissues (crop, proventriculus, duodenum, jejunum, ileum, and cecal tonsils), except in the bursa of Fabricius that presented the highest expression level. The addition of probiotics and organic acids for either 7 or 14 consecutive days demonstrated a direct effect of probiotics and organic acids on chAng4 expression; moreover, broilers receiving probiotics and organic acids for only 7 D showed higher levels of chAng4 expression compared with those treated for 14 D. Broilers without treatment had a constant high level of expression in cecal tonsils and bursa. In conclusion, we were able to identify and characterize a new antimicrobial gene in chickens (chAng4) throughout the gastrointestinal tract. chAng4 mRNA gene expression was associated with the presence of naturally occurring and supplemented (probiotic) bacteria. The encoded protein might have a potential bactericidal effect against intestinal nonpathogenic and pathogenic microbes, modulating the intestinal microbiota and the innate immunity, and thereby may help minimize the use of antibiotics in poultry feed.

Changes with age in density of goblet cells in the small intestine of broiler chicks

Goblet cells secrete mucin 2 (Muc2), which is a major component of the mucus that lines the intestinal tract and creates a protective barrier between pathogens and the intestinal epithelial cells and thus are important for chick health. The objectives of this study were to determine the age-specific and intestinal segment-specific expression of Muc2 mRNA and changes in the number of goblet cells from late embryogenesis to early after hatch. Small intestinal samples from the duodenum, jejunum, and ileum were collected from Cobb 500 broilers at embryonic day 19 (e19), day of hatch (doh), and day 2 and 4 after hatch. Cells expressing Muc2 mRNA and mucin glycoprotein were detected by in situ hybridization or alcian blue and periodic acid-Schiff staining, respectively. Along the villi, there were many more cells expressing Muc2 mRNA than those stained for mucin glycoprotein. In the crypt, cells expressing Muc2 mRNA did not stain for mucin glycoprotein. There was an increase in the density of goblet cells in the villi and Muc2 mRNA expressing cells in the crypts of the jejunum and ileum from e19 to doh and day 2 to day 4, with no change between doh and day 2. In contrast, in the duodenum, the density of goblet cells in the villi and Muc2 mRNA expressing cells in the crypts remained constant from e19 to day 4. At day 4, the villi in the ileum had a greater density of goblet cells than the duodenum. In the crypt, the ileum had a greater density of Muc2 mRNA expressing cells than the duodenum at doh, and the ileum and jejunum both had greater densities of Muc2 mRNA expressing cells than the duodenum at day 4. These results indicate that the population of goblet cells has reached a steady state by doh in the duodenum, whereas in the jejunum and ileum, a steady-state population was not reached until after hatch.

Black soldier fly and gut health in broiler chickens: insights into the relationship between cecal microbiota and intestinal mucin composition

Background

The relationship between diet and intestinal microbiota and mucin composition appears to be fundamental for poultry gut health. The effects of insect meal (whose role as alternative feed ingredient is now well recognized) on gut microbiota and mucin composition have recently been reported in Tenebrio molitor-fed free-range and broiler chickens, but no data are currently available for Hermetia illucens (HI)-fed broilers. The present study evaluated the effects of dietary HI meal inclusion on cecal microbiota and intestinal mucin composition of broiler chickens.

Results

A total of 256 male broiler chickens were allotted to 4 dietary treatments (control diet [C] and 5%, 10% and 15% HI meal inclusion, with 8 replicate pens/treatment and 8 birds/pen) and slaughtered at 35 d of age (2 animals/pen, 16 birds/diet). The cecal microbiota assessment by 16S rRNA amplicon based sequencing showed lower alpha diversity in HI15 chickens (Shannon, P < 0.05) and higher beta diversity (Adonis and ANOSIM, P < 0.001) in birds fed HI diets than C. Furthermore, HI15 birds displayed significant increase of the relative abundance of Proteobacteria phylum (False Discovery Rate [FDR] <  0.05) when compared to HI10. L-Ruminococcus (Ruminococcus from Lachnospiraceae family), Faecalibacterium, Blautia and Clostridium genera were found to be characteristic of HI5 cecal microbiota (FDR < 0.05), while broiler chickens fed HI10 and HI15 diets were characterized (FDR < 0.05) by Lactobacillus and Ruminococcus (HI10) and Bacteroides, Roseburia and Helicobacter genera (HI15). Periodic-acid Schiff, Alcian Blue pH 2.5 and high iron diamine staining on small and large intestine also demonstrated lower mucin staining intensity in the intestinal villi of HI10 and HI15 birds than C (P < 0.05).

Conclusions

Dietary HI meal utilization at low inclusion levels (i.e., 5%) positively influenced either the cecal microbiota or the gut mucin dynamics in terms of selection of potentially beneficial bacteria and increase in villi mucins. However, high inclusion levels (in particular the 15%) may have a negative influence in terms of partial reduction of microbial complexity, reduction of potentially beneficial bacteria, selection of bacteria with mucolytic activity and decrease in villi mucins.

Effect of a "diluted" diet containing 10% lignocellulose on the gastrointestinal tract, intestinal microbiota, and excreta characteristics of dual purpose laying hens

Low performing dual purpose hens have different nutritional requirements compared to conventional hybrid hens. Lignocellulose is a low fermentable polymer, acting as a diet diluent and may influence physiological and digestive processes. This study investigated the effect of a 10% dietary lignocellulose dilution on the development of gastrointestinal organs, intestinal morphology, intestinal microbiota, and excreta characteristics of dual purpose hens. One-day-old female Lohmann Dual chicks were allocated to 12 pens and fed two different diets: A standard control diet (CON) and a treatment diet (LC), based on CON but diluted with 10% lignocellulose (ARBOCEL®). At 52 wk of age, gastrointestinal organs were extracted and weights determined. Colorectal tissue samples were chemically fixed and stained for histomorphological examinations. Cecal digesta samples were analyzed for bacterial metabolites and composition using gas chromatography, HPLC, photometry, and PCR. Excreta dry matter and viscosity was consistently assessed during the trial. LC-fed hens showed increased weights of the gizzard (P = 0.003), small (P < 0.001), and large intestine (P = 0.048) compared to hens fed CON. LC-fed hens had a larger colorectal villus area (P = 0.049), a higher mucosal enlargement factor of villi (P = 0.016) and crypts (P = 0.030) than CON-fed hens. The concentration of short-chain fatty acids (SCFAs) (P = 0.017) and ammonia (P = 0.013) was higher in CON-fed hens compared to LC-fed hens. Bacterial composition and activity was generally not affected by feeding the different diets. LC-fed hens had a higher excreta dry matter content than hens fed CON at 10 (P < 0.001), 17 (P < 0.001), and 22 (P = 0.002) wk of age. Correlation analyses revealed a negative relationship between the concentration of SCFAs in the cecum and the colorectal villus surface area (P < 0.01). In conclusion, the feeding of high levels of lignocellulose increased gastrointestinal organ weights and colorectal surface area in dual purpose laying hens. A higher intestinal surface area in combination with lower concentrations of SCFAs might indicate a compensatory reaction of hens fed LC enhancing the absorption of bacterial metabolites by increasing the intestinal mucosal surface.

Effect of in ovo feeding of amino acids and dextrose solutions on hatchability, body weight, intestinal development and liver glycogen reserves in newborn chicks

Early development of the digestive tract is crucial for achieving maximal growth and development of chickens. This study examined the effects of in ovo (IO) feeding of 0.70 mL of dextrose (10.00% and 20.00%) or amino acids solutions into the yolk sac at day 14 of incubation on small intestine histomorphometry and histomorphology, intestinal development, hatchability, body weight, and liver glycogen reserves in newborn chicks. Results showed body weight in amino acid fed hatchlings was higher than control and dextrose groups non-significantly, but hatchability was lower in amino acid group than others. Also, diameter of glycogen vacuoles in all IO treatment groups was more than control. Administration of exogenous dextrose and amino acids solutions into the yolk sac enhanced intestinal development by increasing the size and surface area of the villi and changed villi shape as well. It seems that dextrose or amino acids solutions could improve the intestinal villi development, while they did not affect finger-like villi in jejunum.

Growth performance, carcass traits and digestive function of broiler chickens fed diets with graded levels of corn resistant starch

1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens.