Chicken Small Intestine Research Articles

Molecular Identification of Ascaridia galli in Chickens from Traditional Markets in Surabaya, Indonesia

Background: Ascaridia galli is pathogenic in chickens and causes substantially reduced growth rates, weight loss, low egg production and death in infected chickens. It is necessary to carry out research on the molecular identification of A. galli in chickens in traditional markets in Surabaya using the Polymerase Chain Reaction (PCR) method with the COX-1 mtDNA gene primer. Methods: This research was carried out from April to July 2023. The number of samples used in this research was 100 chicken small intestines taken from traditional markets in Surabaya, Indonesia. A. galli worms obtained from worm collections were identified according to the morphology of the A. galli worms. DNA extraction was carried out followed by PCR laboratory procedure. The specific primers utilized were designed to target the COX-1 gene and the amplified products were visualized in 1.5% agarose. Result: The A. galli worm has a long body posture. Male A. galli worms measure 30-50 mm long; while, adult female A. galli worms measure 65-80 mm long. The results of electrophoresis with a 2% agarose gel run for 30 minutes at 100 Volts and visualized under ultraviolet light using a UV Transilluminator (Geldoc) showed the presence of a single band of the COX-1 mtDNA gene in the 533 base pair. Infection with A. galli worms often causes reduced growth rates and decreased body weight, which is associated with increased worm weight.

Fecal microbiota transplantation provides insights into the consequences of transcriptome profiles and cell energy in response to circadian misalignment of chickens

The circadian misalignment (CM) disordered circadian rhythms exert adverse effects on animals. Poultry as one of animals suffers health and welfare problems due to long-term lighting photoperiods caused by CM. However, the roles of CM on organ development, cell growth, metabolism and immune are still unclear in chickens. In this study, a Chinese dual-purpose native breed, was used to explore the effects of CM on transcriptomic pattern of brain and cell energy biogenesis, and further fecal microbiota transplantation (FMT) was applied to investigate its "therapy" effect from CM suffering. Our results showed that the CM led to stunting in brain and small intestine of chicken. CM decreased of cell proliferation, and energy production, mtDNA copies and expression of genes related to cell cycle or mitochondrial biogenetics, while it upregulated the reactive oxygen species (ROS) level and the sensitivity to inflammation. Interestingly, FMT rescued the organ developmental defects and cell dysfunctions induced by CM. Circadian misalignment brought about abnormal tissue and cell developments, energy biogenesis, and immune response in birds. This study provided a comprehensive perspective on understanding the regulation of CM and FMT on bird development and welfare.

Fermented bamboo powder activates gut odorant receptors, and promotes intestinal health and growth performance of dwarf yellow-feathered broiler chickens

The present study investigated the effects of fermented bamboo powder (FPB) on gut odorant receptors (OR), intestinal health, and growth performance of dwarf yellow-feathered broiler chickens. Six hundred (600) healthy 1-day-old chicks were randomly assigned into 2 groups, with 10 replicates consisting of 30 chicks each. The control group was fed a basal diet. In contrast, the experimental group was fed the basal diet supplemented with 1.0, 2.0, 4.0, and 6.0 g/kg FBP for 4 different phases, namely phase I (1-22 d), phase II (23-45 d), phase III (46-60 d), and phase IV (61-77 d), respectively. The first 2 phases were considered pretreatment (0-45 d), and the remaining were experimental (46-77 d) periods. The tissue samples were collected from phase IV. The chickens in the FBP supplementation group exhibited a significant increment in body weight gain, evisceration yield, breast, thigh, and liver weight, while also experiencing a decrease in the FCR (P < 0.05). Furthermore, the villus height, crypt depth, and villus area exhibited significant increases in the FBP group (P < 0.01). Additionally, the secretion levels of gut hormones such as glucagon-like peptide-1, peptide YY, cholecystokinin, and 5-hydroxytryptamine were significantly elevated in the serum, duodenum, jejunum, and ileum tissues in the FBP group (P < 0.05). The results of qRT-PCR indicated that ORs had responsive expression in the gizzard, proventriculus, and small intestine of chickens when fed with the FBP diet (P < 0.05). Notably, the expression of the COR1, COR2, COR4, COR6, COR8, COR9, OR52R1, OR51M1, OR1F2P, OR5AP2, and OR14J1L112 genes was stronger in the small intestines compared to the gizzard and proventriculus. In conclusion, these results suggest that the FPB plays a crucial role in growth performance, activation of ORs, and gut health and development.

Peranan Probiotik Lactobacillus plantarum IIA-1A5 dalam Meningkatkan Ketahanan Tubuh, Performa, dan Kualitas Telur Ayam Komersial

Probiotics are microorganisms that are non-pathogenic and beneficial for health when used in certain doses through the mechanism of increasing the function of the small intestine in chickens. This study aims to analyze the effect of adding the probiotic Lactobacillus plantarum IIA-1A5 to feed to improve the body's immune system, production performance, and egg quality in laying hens aged 49‒52 weeks. The experimental design used was a Completely Randomized Design (CRD). The treatment for adding the probiotic Lactobacillus plantarum IIA-1A5 to feed consists of four treatment levels, namely P0 (without probiotics), P1 (feed + 8.1 x 106 cfu/g or 1 g/kg feed), P2 (feed + 2.43 x 107 cfu/g or 3 g/kg feed), and P3 (feed + 4.86 x 107 cfu/g or 6 g/kg feed). The results of the study showed that administering the probiotic Lactobacillus plantarum IIA-1A5 in feed could reduce Escherichia coli bacteria in the small intestine of laying hens. Giving the probiotic Lactobacillus plantarum also had a significant effect (P&lt;0.05) on feed consumption and egg yolk color. The addition of the probiotic Lactobacillus plantarum IIA-1A5 in feed can increase animal resistance, performance, and quality of chicken eggs. The use of probiotics with a treatment level of 1 g kg-1 feed (8.1 x 106 cfu g-1) showed the best results.&#x0D; &#x0D; Keywords: heat stress, laying hens, probiotic

Molecular and cellular characterization of immunity conferred by lactobacilli against necrotic enteritis in chickens.

Necrotic enteritis is an important enteric disease of poultry that can be controlled with in-feed antibiotics. However, with the concerns over antimicrobial resistance, there is an increased interest in the use of alternatives. Probiotics are one of the alternatives that have gained considerable attention due to their antimicrobial and immunomodulatory activities. Therefore, in the present study, we evaluated the effects of two different Lactobacillus species alone or as a cocktail on prevention of necrotic enteritis. Day-old male broiler chickens were divided into five groups and on days 1, 8, 15, and 22, birds in groups 2 and 3 received 1×108 colony forming units (CFU) of L. johnsonii and L. reuteri, respectively. Group 4 received probiotic cocktails containing both bacteria (108 CFU/bird) and the negative and positive control groups did not receive any lactobacilli. Starting on day 23 post-hatch, birds in all groups (except the negative control group) were orally challenged twice per day with 3×108 CFU of a pathogenic C. perfringens strain for 3 days. Tissue and cecal samples were collected before and after challenge to assess gene expression, lymphocyte subsets determination, and microbiome analysis. On day 26 of age, lesion scoring was performed. The results demonstrated that the group that received the lactobacilli cocktail had significantly reduced lesion scores compared to the positive control group. In addition, the expression of interleukin (IL)-12 in the jejunum and CXC motif chemokine ligand 8 (CXCL8), IL-13, and IL-17 in the ileum were downregulated in the group that received the lactobacilli cocktail when compared to the positive control. Treating chickens with the lactobacilli cocktail prior to challenge enhanced the percentage of CD3-CD8+ cells and Bu-1+IgY+ B cells in the ileum and increased the frequency of monocyte/macrophages, CD3-CD8+ cells, Bu-1+IgM+, and Bu-1+IgY+ B cells in the jejunum. Treatment with the lactobacilli cocktail reduced the relative expression of Gamma-Protobacteria and Firmicutes compared to the positive control group. In conclusion, the results presented here suggest that treatment with the lactobacilli cocktail containing L. johnsonii and L. reuteri reduced necrotic enteritis lesions in the small intestine of chickens, possibly through the modulation of immune responses.

The Impacts of Vegetables and Fruits by Products on Growth and Health of Broiler Chickens

Agro-industrial by-products, which are not intended for human consumption, can serve as substitutes for traditional animal feed ingredients in animal nutrition. This can result in the production of animal products without causing competition for land or exacerbating the food versus feed dilemma, ultimately promoting environmental and economic sustainability. Utilizing co-products as animal feed has the potential to reduce feeding costs while enhancing the productive parameters, quality, animal welfare and sustainability of animal products. Numerous studies have indicated that fruits and vegetables are considered as significant sources of bioactive compounds. The extensive process of industrialization leads to the creation of considerable amounts of by-products, giving rise to grave ecological concerns. Hence, such a scenario necessitates the formulation of innovative approaches for effectively utilizing the resultant wastes, ensuring the potential to fabricate novel products with enhanced value. The generated by-products, reveal similar or higher antioxidant activity. It is recognized that these secondary products comprise various bioactive substances and may have the ability to serve as nutraceuticals for poultry, promoting their health and overall wellness. This review aims to summarize the exploitation of fruit wastes, namely, apple, citrus, banana, mango, pineapple and grape as well as vegetable by-products which are derived from tomato and olive cultivation. These byproducts can be in supplementation or substitution format. Some of these byproducts presented the following results: The addition of 2% dried sweet orange pulp to the diet significantly increased feed intake and total weight gain in broilers and the inclusion of dried orange pulp in broiler diets was found to reduce serum triglycerides and cholesterol. Also, the including of 10% apple peel in the diet led to an increase in the weight of the gizzard and small intestine in chickens. Additionally, diets containing 5% and 10% apple peel waste resulted in higher levels of lipids and HDL (high-density lipoprotein) in the blood serum, while LDL (low-density lipoprotein) and malondialdehyde levels decreased. Moreover, the including of 10% banana peel in poultry feed led to improved feed efficiency, feed conversion and the quality of poultry eggs and meat. However, the inclusion of olive cake with phytase to broiler chickens’ diet presented an increase of growth parameters increased. The incorporation of 10% of OC with phytase also resulted a reduction in plasma cholesterol and triglycerides and an increase in plasma inorganic phosphorus.

Research Note: Junctional adhesion molecule A is expressed in epithelial cells of the crypt and villi whereas junctional adhesion molecule 2 is expressed in vascular cells

A functional intestinal barrier is essential for a healthy intestine. This barrier includes an apical tight junctional complex between adjacent intestinal epithelial cells. The tight junctions (TJ) are multiprotein junctional complexes that consist of a number of members of the occludin, claudin, zona occludens, and junctional adhesion molecule families. The mRNA expression of junctional adhesin molecule A (JAMA) and junctional adhesion molecule 2 (JAM2) are 2 TJ mRNAs that are often used to assess intestinal barrier integrity. The objective of this study was to use in situ hybridization to identify cells that express JAMA and JAM2 mRNA in the small intestine of chickens. In the jejunum of a 21 d old broiler, JAMA mRNA was highly expressed in the epithelial cells of the villi and crypt. By contrast, JAM2 mRNA was located in the vascular system in the center of the villi and in the lamina propria. These results demonstrate that JAMA and not JAM2 is the appropriate gene to use when assessing TJ between intestinal epithelial cells.

Lactobacillus fermentum 1.2133 display probiotic potential in vitro and protect against Salmonella pullorum in chicken of infection.

The efficacy of Lactobacillus as an antibiotic substitute has been investigated as one of the potential strategies to prevent Salmonella infection in poultry. The purpose of this study was to explore the antibacterial activity of Lactobacillus fermentum 1.2133 (Lact. fermentum 1.2133) against Salmonella pullorum CVCC533 (Salm. pullorum CVCC533) and its effect on chickens infected with Salm. pullorum CVCC533. Results showed that Lact. fermentans 1.2133 has antibacterial activity against Salm. pullorum CVCC533 and the cell-free fermentation supernatant of Lact. fermentum 1.2133 had a bactericidal effect on the bacteria in the Salm. pullorum CVCC533 biofilm by significantly reducing the number of Salmonella and aerobic bacteria in the chicken duodenum, ileum, and cecum, including Escherichia shigella (P<0.05), improved the species abundance of Lactobacilli (P<0.05). The damage to the chicken intestine by Salm. pullorum CVCC533 was reduced as the expression of avian beta-defensin 2 (AvBD2) mRNA in chicken small intestine was increased (P<0.05). The results showed that Lact. fermentum 1.2133 had the potential to be a probiotic for poultry due to its regulation of intestinal AvBD2 mRNA as well as its intestinal flora.

ОЦЕНКА УРОВНЯ ЭКСПРЕССИИ ГЕНА LCORL В КИШЕЧНИКЕ КУР ГЕНОФОНДНЫХ ПОРОД

Previous studies have been revealed LCORL gene influence on growth processes in man and in different animal species. It has determined the gene choice as candidate gene for studying its expression level in different breeds of chicken. This work task has been evaluation of LCORL gene transcription activity in chicken intestine depending on their genotype and breed variability. Analysis of this gene expression in chicken small intestine tissues has revealed the highest expression level in Pushkinskaya breed and the lowest level in Rod Ayland breed. The level of LCORL gene expression has been the largest in Pushkinskaya and Italian chicken breeds that are heterozygous in SNP (rs 15619223, A&gt;С).

Transcriptome-wide analysis reveals gluten-induced suppression of small intestine development in young chickens.

Wheat gluten is an increasingly common ingredient in poultry diets but its impact on the small intestine in chicken is not fully understood. This study aimed to identify effects of high-gluten diets on chicken small intestines and the variation of their associated transcriptional responses by age. A total of 120 broilers (Ross Strain) were used to perform two animal experiments consisting of two gluten inclusion levels (0% or 25%) by bird’s age (1 week or 4 weeks). Transcriptomics and histochemical techniques were employed to study the effect of gluten on their duodenal mucosa using randomly selected 12 broilers (3 chicks per group). A reduction in feed intake and body weight gain was found in the broilers fed a high-gluten containing diet at both ages. Histochemical photomicrographs showed a reduced villus height to crypt depth ratio in the duodenum of gluten-fed broilers at 1 week. We found mainly a significant effect on the gene expression of duodenal mucosa in gluten-fed broilers at 1 week (289 differentially expressed genes [DEGs]). Pathway analyses revealed that the significant DEGs were mainly involved in ribosome, oxidative phosphorylation, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. These pathways are involved in ribosome protein biogenesis, oxidative phosphorylation and fatty acid metabolism, respectively. Our results suggest a pattern of differential gene expression in these pathways that can be linked to chronic inflammation, suppression of cell proliferation, cell cycle arrest and apoptosis. And via such a mode of action, high-gluten inclusion levels in poultry diets could lead to the observed retardation of villi development in the duodenal mucosa of young broiler chicken.

Effect of berberine on copper and zinc levels in chickens infected with Eimeria tenella

Berberine, a traditional Chinese medicine, was found to exhibit anticoccidial activity. However, its mechanism is unclear. Trace metals such as copper and zinc are extremely low (less than 0.01% of the total weight of the body) but play a vital role in organisms. In the present study, we investigated the effect of berberine on copper and zinc levels in chickens infected with Eimeria tenella. Firstly, our data confirmed that infected chickens with E. tenella exhibited classic impairment on the 8th day of post infection, such as weight loss and increased feed conversion. Further study showed that E. tenella infection decreased the contents of copper and zinc in the liver and serum of chickens. Berberine was similar to amprolium and significantly improved the pathogenic conditions. Berberine could restore copper and zinc imbalance caused by E. tenella in chickens to a large extent. Studies on the development of cecum lesions demonstrated that the protective effect of berberine on the intestinal cecum was similar to that of the Cu/Zn mixture. Additionally, the mRNA expression of several metal transport related genes of the chick small intestine, including zinc transporter 1, copper transporter 1 and divalent metal ion transporter 1, was elevated by the treatment with berberine. Taken together, we speculate that the anticoccidial activity of berberine may be related to the maintenance of certain metals (Cu/Zn) homeostasis by affecting mRNA expression of their transport genes. However, the mode of action of BBR on these vital metals in the chicks infected with E. tenella still needs to be further studied.

Supplementation of Dietary Quercetin and Vitamin E Promotes the Intestinal Structure and Immune Barrier Integrity in Aged Breeder Hens.

In aged animals, the physiological functions of the gastrointestinal tract (GIT) are reduced. Dietary intervention is necessary to re-activate GIT functions. The objective of this study was to investigate the impacts of dietary combination of quercetin (Q) and vitamin E (VE) on the intestinal structure and barrier integrity in aged breeder chickens. A sum of 400 (65-wks-old) Tianfu breeder hens were randomly allotted into four (4) groups with four (4) replicates, and fed with basal diet; basal diet supplemented with 0.4g/kg of Q; basal diet supplemented with 0.2g/kg of VE; and basal diet supplemented with the combination of Q (0.4 g/kg) and VE (0.2 g/kg) for 14 weeks. At the end of the 14th week, serum and gut segments were collected from eight hens per group for analyses. The results showed that Q+VE exerted synergistic effects on intestinal morphology by promoting villi height and crypt depth (P < 0.05), as well as mitigated the intestinal inflammatory damage of the aged hens, but decreased the concentration of serum D-lactate and diamine oxidase; and increased the levels of secretory immunoglobulin A (sIgA) and Mucin-2 mRNA (P < 0.05). Furthermore, the mRNA expression of intestinal tight junction proteins including occludin, ZO1, and claudin-1 was increased by Q+VE (P < 0.05). Moreover, Q+VE decreased the mRNA expression of the pro-inflammatory genes (TNF-α, IL-6, and IL-1β), and increased the expression of anti-inflammatory genes (IL-10 and IL-4) (P < 0.05). These results were consistent with the mRNA expression of Bax and Bcl-2. In addition, Q+VE protected the small intestinal tract from oxidative damage by increasing the levels of superoxide dismutase, total antioxidant capacity, glutathione peroxidase, catalase (P < 0.05), and the mRNA expression of SOD1 and GPx-2. However, Q+VE decreased malondialdehyde levels in the intestine compared to the control (P < 0.05). These results indicated that dietary Q+VE improved intestinal function in aged breeder hens, by protecting the intestinal structure and integrity. Therefore, Q+VE could act as an anti-aging agent to elevate the physiological functions of the small intestine in chickens.

Comparative Microbial Conversion of Deoxynivalenol and Acetylated Deoxynivalenol in Different Parts of the Chicken Intestine as Detected In Vitro and Translated to the In Vivo Situation.

To assess potential differences in the intestinal microbial metabolism of deoxynivalenol (DON) and its acetylated forms 3-Ac-DON and 15-Ac-DON, in vitro anaerobic incubations with intestinal contents from chickens were conducted. Quantitative microbiota characterization was obtained by 16S rRNA sequencing. The data showed substantial differences in the level of different toxin conversions by the microbiota from the different intestinal segments. The transformation rate of DON to its metabolite DOM-1 decreased in the order of cecum > ileum > jejunum, and caecum contents could completely transform DON to DOM-1 within 24 h. However, no transformation appeared in the duodenum. For 3-Ac-DON, the deacetylation rate decreased as follows: duodenum > caecum > ileum > jejunum, and 100% deacetylation was observed in the duodenum within 24 h. The deacetylation of 15-Ac-DON decreased in the order of cecum > duodenum > ileum with no transformation in the jejunum. Some genera may contribute to the transformation of the toxins. Based on the in vitro kinetic parameters and their scaling to the in vivo situation, it was concluded that in the chicken small intestine, the deconjugation of both 3-Ac-DON and 15-Ac-DON will not likely be completed upon full transit. Whether this also holds for humans remains to be established.

Short-chain fatty acids promote jejunal barrier function and caecal muscle contractibility in laying hens ex vivo

ABSTRACT 1. Short-chain fatty acids (SCFA) exert beneficial actions in the gut; nevertheless, information about the effect of SCFA on physiological responses in the small intestine of chickens is rare. 2. The aim of this study was to assess the effect of 1) different molar acetate:butyrate ratios (Ac:But; Experiment 1; 78.5% acetate and 7.3% butyrate versus 71.4% acetate and 14.0% butyrate) and 2) SCFA concentrations (Experiment 2; final concentration in chambers: 70.5 versus 141 µmol SCFA/ml buffer) on the jejunal and caecal contractibility and jejunal barrier function in laying hens. The change in muscle contractibility due to the SCFA was measured in mid-jejunal and caecal segments (n = 4 each per hen) from four laying hens using the organ bath system after precontraction with acetylcholine for 15 min. Changes in short-circuit current (ISC) and transepithelial tissue conductivity (GT) as indicators for net ion flux and barrier function, respectively, were measured in mid-jejunal tissue (n = 3/hen and treatment), mounted into Ussing chambers. 3. In Experiment 1, the addition of SCFA, irrespective of the Ac:But ratio, decreased jejunal muscle tension (P < 0.05), jejunal GT as well as caused a less negative ISC (P < 0.05). In Experiment 2, the increasing SCFA concentrations increased the caecal muscle contraction and jejunal ISC by 75.6% while decreasing the GT by up to 19.6% (P < 0.05). 4. In conclusion, results demonstrate that increasing butyrate proportions and SCFA concentrations stimulate caecal muscle contraction, thereby increasing caecal mixing and emptying in vivo. Jejunal ISC and GT support a strong SCFA sensing capacity in the jejunum, as both, more butyrate and higher SCFA, increased mucosal ion uptake and barrier function.

Effects of Heat Stress on Expression of Heat Shock Proteins in the Small Intestine of Wenchang Chicks

ABSTRACT In this study, immunohistochemistry and real-time fluorescent-based quantitative PCR were used to evaluate the expression of heat shock protein (HSP) 60, HSP70, and HSP90 in the small intestine of Wenchang chicks. Compared with the control group (CK), the positive expression of HSP60 and HSP60 mRNA in the heat stress group (HS) were initially higher and subsequently lower in the duodenum (p<0.01). In the HS jejunum, the levels of HSP60 were higher (p<0.01) and the HSP60 mRNA was lower (p<0.05). Whereas the levels of HSP60 in the HS ileum were higher (p<0.05) and then lower (p<0.01), and the HSP60 mRNA was higher (p<0.01). The levels of HSP70 were higher (p<0.01) and the HSP70 mRNA was lower in the duodenum (p<0.05), while the expression of both HSP70 and HSP70 mRNA was higher in the jejunum (p<0.01) and the ileum (p<0.05) of the HS. In the HS duodenum the levels of HSP90 were lower and then higher (p<0.01), and the HSP90 mRNA was higher (p<0.01). The expression of both HSP90 and HSP90 mRNA was higher in the HS jejunum (p<0.05). The levels of HSP90 were lower while the HSP90 mRNA was higher in the HS ileum (p<0.01). These results indicate that heat stress disturbed the expression of HSP60, HSP70, and HSP90 in the small intestine of chicks.

Physiological Stress Mediated by Corticosterone Administration Alters Intestinal Bacterial Communities and Increases the Relative Abundance of Clostridium perfringens in the Small Intestine of Chickens.

A model of physiological stress mediated by the administration of corticosterone (CORT) was used to investigate the impact of stress on the intestinal microbiota of chickens. Birds were administered CORT in their drinking water at 0, 10 (low dose CORT; LDC), and 30 (high dose CORT; HDC) mg/L. Digesta from the small intestine and ceca were examined after 1, 5, and 12 days post-initiation of CORT administration by 16S rRNA gene sequencing. A decrease in phylogenetic diversity and altered composition of bacteria were observed for HDC in the small intestine. Analysis by ANOVA-Like Differential Expression 2 (ALDEx2) showed that densities of Clostridium sensu stricto 1 bacteria were increased in the small intestine for LDC and HDC. Quantitative PCR confirmed that CORT administration increased densities of Clostridium perfringens in the small intestine, but only HDC was associated with increased densities of the bacterium in ceca. Predictive functional analysis by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) showed pathways of carbohydrate metabolism to be enriched with CORT, and amino acid synthesis to be enriched in control birds in the small intestine. In conclusion, physiological stress mediated by CORT modulated bacterial communities in the small intestine and increased densities of C. perfringens. This implicates stress as an important mediator of this important enteric pathogen in poultry.

Pharmacokinetics, Activity, and Residue Elimination of R- and S-Diclazuril in Broiler Chickens

Diclazuril (DIC) is widely used as a racemic mixture to prevent and treat coccidiosis in farm animals, while the pharmacokinetics, bioactivity, and toxicity of DIC enantiomers are not known at all. This study first established a simple, sensitive, and reliable liquid chromatography tandem mass spectrometry method for separation of R-DIC and S-DIC and their analyses. Then, it was applied to investigate the stereoselective pharmacokinetics and residual elimination of individual enantiomers, and their anticoccidial activity was also evaluated in broiler chickens. The results indicated that the area under the concentration-time curve (AUC) and elimination half-life (t1/2β) were significantly different (p < 0.05) for two enantiomers in chicken plasma. The AUC and t1/2β of S-DIC were approximately 2 and 1.4 times those of R-DIC, respectively. The residual elimination of DIC enantiomers in chicken tissues was also stereoselective. The concentrations of S-DIC in chicken muscle and liver were greater than those of R-DIC, and it is the opposite in the kidney. There was no significant difference (p > 0.05) in the anticoccidial activity of racemate and enantiomers when a single enantiomer in feed was added above 0.5 mg kg-1. However, the anticoccidial activity of R-DIC (0.25 mg kg-1) was significantly higher (p < 0.05) than that of S-DIC (0.25 mg kg-1) in the diet. It should be mentioned that in chicken small intestine and cecum, the enantiomerization rate of each enantiomer in the infection group was faster than that in the uninfected group.

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.

Genome-wide analysis of differentially expressed profiles of mRNAs, lncRNAs and circRNAs in chickens during Eimeria necatrix infection

BackgroundEimeria necatrix, the most highly pathogenic coccidian in chicken small intestines, can cause high morbidity and mortality in susceptible birds and devastating economic losses in poultry production, but the underlying molecular mechanisms in interaction between chicken and E. necatrix are not entirely revealed. Accumulating evidence shows that the long-non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are key regulators in various infectious diseases. However, the expression profiles and roles of these two non-coding RNAs (ncRNAs) during E. necatrix infection are still unclear.MethodsThe expression profiles of mRNAs, lncRNAs and circRNAs in mid-segments of chicken small intestines at 108 h post-infection (pi) with E. necatrix were analyzed by using the RNA-seq technique.ResultsAfter strict filtering of raw data, we putatively identified 49,183 mRNAs, 818 lncRNAs and 4153 circRNAs. The obtained lncRNAs were classified into four types, including 228 (27.87%) intergenic, 67 (8.19%) intronic, 166 (20.29%) anti-sense and 357 (43.64%) sense-overlapping lncRNAs; of these, 571 were found to be novel. Five types were also predicted for putative circRNAs, including 180 exonic, 54 intronic, 113 antisense, 109 intergenic and 3697 sense-overlapping circRNAs. Eimeria necatrix infection significantly altered the expression of 1543 mRNAs (707 upregulated and 836 downregulated), 95 lncRNAs (49 upregulated and 46 downregulated) and 13 circRNAs (9 upregulated and 4 downregulated). Target predictions revealed that 38 aberrantly expressed lncRNAs would cis-regulate 73 mRNAs, and 1453 mRNAs could be trans-regulated by 87 differentially regulated lncRNAs. Additionally, 109 potential sponging miRNAs were also identified for 9 circRNAs. GO and KEGG enrichment analysis of target mRNAs for lncRNAs, and sponging miRNA targets and source genes for circRNAs identified associations of both lncRNAs and circRNAs with host immune defense and pathogenesis during E. necatrix infection.ConclusionsTo the best of our knowledge, the present study provides the first genome-wide analysis of mRNAs, lncRNAs and circRNAs in chicken small intestines infected with E. necatrix. The obtained data will offer novel clues for exploring the interaction mechanisms between chickens and Eimeria spp.

Micro-RNA expression profile of chicken small intestines during Eimeria necatrix infection

Eimeria necatrix is a high pathogenic pathogen second to Eimeria tenella causing chicken coccidiosis. However, the precise underlying molecular mechanisms of interaction between E. necatrix and chickens are not fully understood. Accumulating evidences suggest that micro-RNAs (miRNAs) play pivotal regulatory roles in various diseases, including parasitic diseases. In the present study, the expression profile of miRNAs in Hy-line variety white chicken small intestines infected with E. necatrix was studied by using deep sequencing. A total of 35 miRNAs (including 16 significantly upregulated and 19 significantly downregulated miRNAs) were significantly differentially expressed (DE) in infected tissues at 108 h post-infection (pi). Real-time polymerase chain of 10 miRNAs (including 5 upregulated and 5 downregulated) randomly selected successfully confirmed the effectiveness of deep sequencing. Target prediction showed that 4,568 mRNAs could be regulated by 21 (including 12 upregulated and 9 downregulated) of 35 differentially expressed miRNAs. Functional analysis indicated that target genes of these differentially expressed miRNAs would be involved in pathways related to infection of E. necatrix, including cell differentiation, adhesion, proliferation, and apoptosis (e.g., MAPK signaling pathway and PPAR signaling pathway). To our best knowledge, this is the first study on the miRNA expression profile of small intestines during E. necatrix infection, and the findings in the present study suggested that these DE miRNAs would play important regulatory role in the interaction between E. necatrix and chicken intestines.