Small Intestine Of Broiler Chickens Research Articles

Antimicrobial resistance patterns and genes of Campylobacter jejuni isolated from chickens in Pasuruan, Indonesia.

Poultry is one of the most prominent sources of Campylobacter jejuni, which is also a major means of transmission to people. Campylobacter jejuni contamination in chicken meat comes from chicken feces because it naturally exists in the intestines of chickens. The purpose of this study is to identify the antibiotic resistance patterns and genes of C. jejuni, which was found in chickens in Pasuruan, Indonesia. The samples used in this study were 200 contents of the small intestine of broiler chickens from 40 farms in Pasuruan Regency. The enriched sample was streaked on the selective media of modified charcoal cefoperazone deoxycholate agar containing the CCDA selective supplement. Antimicrobial susceptibility test utilizing the Kirby-Bauer diffusion test method in accordance with Clinical and Laboratory Standards Institute standards. The polymerase chain reaction (PCR) method was used to detect the (hipO), which encodes the C. jejuni strain, fluoroquinolone resistance (gyrA), beta-lactam resistance (blaOXA-61), and tetracycline resistance (tetO) genes. The findings revealed a 14% (28/200) prevalence of C. jejuni in the small intestine of broiler chickens. These isolates showed high resistance to enrofloxacin (92.9%). All isolates (100%) were susceptible to amoxicillin-clavulanate. The PCR results showed all C. jejuni isolates (100%) detected the gyrA gene, 96.4% detected the blaOXA-61 gene, and 50% detected the tetO gene. The findings of antimicrobial resistance at a high level from the small intestine of broiler chickens illustrate the potential threat to human health. To lessen the effects now and in the future, coordinated and suitable action is needed, as well as steps to guarantee the poultry industry's economic survival and public health insurance.

Effects of Different Feeding Frequencies on Broiler Chickens’ Growth Performance and Intestinal Villus Development

This experiment was conducted to determine the effects of feeding frequency on growth performance and development of small intestine in broiler chickens from 1 to 14 days of age. Forty Aber acres broiler chicks at 1 day old were randomly assigned to 4 treatments as follows - T1: feeding once daily (100 % diet at 6:30), T2: feeding twice daily (50 % diet at 6:30 and 18:30), T3: feeding 4 times per day (25 % diet at 6:30, 11:30, 16:30 and 21:30) and T4: feeding 6 times per day (16.67 % diet at 6:30, 9:30, 12:30, 15:30, 18:30 and 21:30). Chickens were fed with commercial broiler rations for 14 days. Growth performance parameters including BW, BW gain, FI and FCR were determined. Changes in intestinal villus morphology were examined by hematoxylin and eosin (H&E) dye staining. Results showed that chickens fed 4 and 6 times per day had lower (p < 0.05) BW, BW gain and FI when compared with chickens fed once daily, from 1 to 7 days of age. However, at 14 days of age, there were no significant differences in all parameters of growth performance. There were no changes in gross anatomy of the small intestine. Fixed feeding 4 and 6 times per day resulted in the villus height of the jejunum and ileum being higher (p < 0.05) than when feeding once a day. Feeding 6 times per day resulted in the highest villus density in jejunum among feed regimes. The results suggested that both once and multiple daily feedings were suitable approaches to achieve optimum growth performance for broiler chickens from 1 to 14 days of age. Fixed feeding 6 times per day being the most beneficial for improving intestinal villus development. HIGHLIGHTS Feeding frequency is one of feed restriction method in broilers management From 1 to 7 days of age feeding fed 4 and 6 times per day show lower growth performance than feeding once daily, but not for 14 days of age Fixed feeding 4 and 6 times per day present the villus height at jejunum and ileum higher than feeding once daily Fixed feeding 6 times per day is the most effective solution for enhancing intestinal villus development Here, the experiment demonstrates for the first time that the compensatory growth effects by frequently feeding is at least mediated through adaptation of villus morphology in the small intestine along with improved feed consumption GRAPHICAL ABSTRACT

Influence of Citrus sinensis seed powder on growth performance, morphological and histological development of the small intestine of broiler chickens

Citrus sinensis (sweet orange) seeds are sources of significant quantities of bioactive compounds and dietary fiber which have shown a range of biological activities in humans but are essentially discarded with abundant waste production. The aim of this study was to evaluate the impact of C. sinensis seed powder on the morphological and histological development of the small intestine of broiler chickens. Four hundred and eighty (480) day-old Cobb 500 broilers chicks were divided into four groups with six replicates and 20 chicks per pen, namely control (T): fed only standard diet; CSS-0.25: standard diet + 0.25% C. sinensis seed powder; CSS-0.50: standard diet + 0.5% C. sinensis seed powder; CSS-0.75: standard diet + 0.75% C. sinensis seed powder over 42 days in a completely randomized design. The results indicated that a diet containing 0.75% of C. sinensis seed powder significantly (p < 0.05) increased the weight and length of the small intestine and its three segments. Furthermore, villi height, villi/crypt ratio, and crypt depth in the jejunal and ileal sections of the intestine increased significantly (p < 0.05) with 0.5% and 0.75% C. sinensis seed powder supplementation. In addition, weight gain and feed conversion ratio were significantly affected in the 0.5 and 0.75% groups on days 21 and 42. In conclusion, supplementation with 0.5% and 0.75% C. sinensis seed powder improves intestinal development and intestinal health in chickens.

Profiling intestinal stem and proliferative cells in the small intestine of broiler chickens via in situ hybridization during the peri-hatch period

Mature small intestines have crypts populated by stem cells which produce replacement cells to maintain the absorptive villus surface area. The embryonic crypt is rudimentary and cells along the villi are capable of proliferation. By 7 d post-hatch the crypts are developed and are the primary sites of proliferation. Research characterizing the proliferative expansion of the small intestine during the peri-hatch period is lacking. The objective of this study was to profile the changes of genes that are markers of stem cells and proliferation: Olfactomedin 4 (Olfm4), Leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5), and marker of proliferation Ki67 from embryonic day 17 to 7 d post-hatch using quantitative PCR and in situ hybridization (ISH). The expression of the stem cell marker genes differed. Olfm4 mRNA increased while Lgr5 mRNA decreased post-hatch. Ki67 mRNA decreased post-hatch in the duodenum and was generally the greatest in the ileum. The ISH was consistent with the quantitative PCR results. Olfm4 mRNA was only seen in the crypts and increased with morphological development of the crypts. In contrast Lgr5 mRNA was expressed in the crypt and the villi in the embryonic periods but became restricted to the intestinal crypt during the post-hatch period. Ki67 mRNA was expressed throughout the intestine pre-hatch, but then expression became restricted to the crypt and the center of the villi. The ontogeny of Olfm4, Lgr5, and Ki67 expressing cells show that proliferation in the peri-hatch intestine changes from along the entire villi to being restricted within the crypts.

Study of the monoglycerides features as a promising alternative to antibiotics in feeding broiler chickens

The spreading of antibiotic resistance in the modern world results from the application of uncontrolled and excessively intensive antibiotics for treating human infectious diseases and their use as growth stimulants in animal farming. In some economically developed countries, restrictions on the use of antibiotics are already applied in order to prevent the generation of resistant strains of microorganisms. An essential component of such means is antibiotic-free strategies in animal farming. Recently, strategies based on the alternative to both antimicrobials and growth promoters have been proposed, including probiotics, prebiotics, synbiotics, enzymes, and organic acids. Short-chain fatty acids and monoglycerides based on them are considered a promising alternatives to antimicrobial agents for poultry farming. However, the effects of these compounds on innate immunity and cytokine production in the intestinal system remain undiscovered. The experiment was carried out using two groups of Cobb 500 cross broilers in the conditions of an industrial poultry farm. The broiler chickens of the research group were exposed to a monoglyceride mixture with С3, С4, С8–С10 fatty acids from 1 to 7 days of life and 16 to 22 days of life at a dose of 0.5 l of the mixture per ton of water. On the 31-st day of life, productive parameters were evaluated, and five birds were selected from each group. The fragments of the duodenum, caecum, and rectum with contents were taken from the bird. In the presented study, the content of interferon-α in the tissue of the small intestine of broiler chickens under the conditions of drinking monoglyceride was studied. To evaluate the beneficial effect of monoglyceride, the state of the microbiome and productive indicators were determined. The study showed that the monoglyceride induces a statistically significant increase in the content of enterococcus in the duodenum, suppresses the growth of staphylococcus, and increases the production of interferon-α. Moreover, average daily weight gain relative to controls was almost 2% greater in monoglyceride-treated chicks. Thus, preservation of the state of microbiota and moderate stimulation of interferon-α production can be essential components of the multidirectional protective effect of monoglycerides and fatty acids.

Histological structure of Pectoralis thoracicus, small intestine, and growth performance of broiler chicken after supplementation of peanut hulls (Arachis hypogaea L.)

The main factor that must be considered in achieving the success of the broiler industry is feed. Processed peanuts from home industries produce waste material in the form of peanut hulls. This study aims to determine the effect of peanut hulls supplementation (PHS) on feed on the histological structure of the Pectoralis thoracicus (PT) muscle, small intestine, and the growth performance of broiler chickens. This study used 360 chickens then divided into 4 treatment groups with each group amounting to 90 with 3 replications. The control group (K) was given basal feed, perlakuan 1 (P1) group with PHS 0.25% /kg basal feed, group P2 with PHS 0.5%/kg basal feed, and group P3 with PHS 1%/kg basal feed. The treatment was carried out until the chicken was 18 days old. The parameters observed were chicken body weight at post-hatch age, 3, 6, 9, 12, 15, and 18 days, feed conversion ratio (FCR), histological structure of pectoralis muscle, and small intestine. Data were analyzed using One-way ANOVA, significance (P≤0.05). The results showed that body weight and FCR values of groups P1, P2, P3 were significant towards the control. The results of the pectoralis muscle treatment group were increased significantly compared to the control. The morphological results of duodenum and jejunum groups P1, P2, P3 were significantly increased towards the control. The conclusions of this study indicate that PHS in feed shows improved body weight, the FCR value, muscle performance of PT, and structure of small intestine of broiler chickens with the addition of the most optimal supplement of peanut hulls, which is 0.5%/kg basal diet.

1,25-Dihydroxycholecalciferol Improved the Growth Performance and Upregulated the Calcium Transporter Gene Expression Levels in the Small Intestine of Broiler Chickens.

1,25-Dihydroxycholecalciferol (1,25-(OH)2-D3) is the final active product of vitamin D. This study aimed to investigate the effects of 1,25-(OH)2-D3 on growth performance, bone development, and calcium (Ca) transporter gene expression levels in the small intestine of broiler chickens. On the day of hatching, 140 female Ross 308 broilers were randomly allotted into two treatments with five replicates (14 birds per replicate). Two levels of 1,25-(OH)2-D3 (0 and 1.25 µg/kg) were added to the basal diet without vitamin D. Results showed that the addition of 1.25 µg/kg 1,25-(OH)2-D3 increased the average daily feed intake and the average daily gain and decreased the feed conversion ratio and mortality in 1- to 19-day-old broiler chickens compared with the basal diet without vitamin D (P<0.05). 1,25-(OH)2-D3 also enhanced the length, weight, ash weight, and the percentage contents of ash, Ca, and P in the tibia and femur of broilers (P<0.05). The mRNA expression levels of the Ca-binding protein (CaBP-D28k) in the duodenum, jejunum, and ileum of 19-day-old broilers increased to 88.1-, 109.1-, and 2.7-fold, respectively, after adding 1,25-(OH)2-D3 (P<0.05). The mRNA expression levels of the plasma membrane Ca ATPase 1b (PMCAlb) in the duodenum and the sodium (Na)/ Ca exchanger 1 (NCX1) in the duodenum and the jejunum were also enhanced to 1.57-2.86 times with the addition of 1,25-(OH)2-D3 (P<0.05). In contrast, the mRNA expression levels of PMCA1b and NCX1 in the ileum and that of vitamin D receptor (VDR) in the small intestine were not affected by 1,25-(OH)2-D3 (P>0.05). These data indicate that 1,25-(OH)2-D3 upregulated Ca transporter gene transcription and promoted Ca2+ absorption in the small intestine, especially in the proximal intestine (duodenum and jejunum), thereby improving growth performance and bone mineralization in broiler chickens.

Clostridium perfringens-Induced Host-Pathogen Transcriptional Changes in the Small Intestine of Broiler Chickens.

Clostridium perfringens is an important opportunistic pathogen that may result in toxin-mediated diseases involving food poisoning/tissue gangrene in humans and various enterotoxaemia in animal species. It is a main etiological agent for necrotic enteritis (NE), the most financially devastating bacterial disease in broiler chickens, especially if raised under antibiotic-free conditions. Importantly, NE is responsible for losses of six billion US dollars annually in the global poultry industry. To investigate the molecular mechanisms of C. perfringens-induced pathogenesis in the gut and its microbiome mRNA levels in C. perfringens-infected and non-infected hosts, we used RNA sequencing technology to perform transcriptional analysis of both host intestine and microbiome using our NE model. The growth rate was significantly impaired in chickens infected by C. perfringens. In total, 13,473 annotated chicken genes were differentially expressed between these two groups, with ninety-six genes showing statistical significance (|absolute fold changes| > 2.0, adjusted p value < 0.05). Genes involved in energy production, MHC Class I antigen, translation, ribosomal structures, and amino acid, nucleotide and carbohydrate metabolism from infected gut tissues were significantly down-regulated. The upregulated genes were mainly engaged in innate and adaptive immunity, cellular processes, genetic information processing, and organismal systems. Additionally, the transcriptional levels of four crucial foodborne pathogens were significantly elevated in a synergic relationship with pathogenic C. perfringens infection. This study presents the profiling data that would likely be a relevant reference for NE pathogenesis and may provide new insights into the mechanism of host-pathogen interaction in C. perfringens-induced NE infection in broiler chickens.

Dietary calcium levels regulate calcium transporter gene expression levels in the small intestine of broiler chickens

ABSTRACT 1. This study investigated the effect of dietary calcium (Ca) levels on growth performance, bone development and Ca transporter gene expression levels in the small intestine of broiler chickens. 2. On the day of hatch, 350, Ross 308 male broilers were randomly allotted to one of five treatments with five replicate pens each and 14 birds per pen. Dietary Ca levels in feed were 5.0, 7.0, 9.0, 11.0 and 13.0 g/kg, in which 9.0 g/kg was in the control diet. All diets contained 4.5 g/kg non-phytate phosphorus (NPP). 3. The increase in dietary Ca levels from 5.0 to 13.0 g/kg did not affect the growth performance of 1- to 18-day-old broilers (P > 0.05). 4. Increasing the Ca levels linearly increased the ash weight and the contents of ash, Ca and phosphorus (P) in the tibia of broilers at 18 days of age (P < 0.05). The contents of ash, Ca and P in broilers fed with 9.0 g/kg Ca were higher than those in birds fed with 5.0 g/kg Ca (P < 0.05). 5. Increasing the Ca levels linearly decreased mRNA expression levels of the Ca-binding protein 28-kDa (CaBP-D28k), plasma membrane Ca-transporting ATPase 1b (PMCAlb), sodium (Na)/Ca exchanger 1 (NCX1), nuclear vitamin D receptor (nVDR) and membrane vitamin D receptor (mVDR) in the duodenum of broilers at 18 d of age (P < 0.05). Similar results were seen in the jejunum and ileum. Broilers fed 9.0–13.0 g/kg Ca in feed had lower mRNA expression levels of CaBP-D28k and PMCAlb in the small intestine than birds fed 5.0 g/kg Ca in feed (P < 0.05). 6. The data indicated that low levels of dietary Ca stimulated its transporter gene transcription and promoted absorption, but high levels of Ca inhibited transporter gene expression and prevented excessive absorption in the small intestine of broiler chickens.

Synergistic effect of exogenous multi-enzyme and phytase on growth performance, nutrients digestibility, blood metabolites, intestinal microflora and morphology in broilers fed corn-wheat-soybean meal diets.

ObjectiveThis study was conducted to investigate the synergistic effect of exogenous multi-enzyme and phytase on growth performance, nutrients digestibility, blood metabolites, intestinal microflora, and morphology in broilers fed corn-wheat-soybean meal diets.MethodsA 2×2 factorial design was used in this study. Four dietary treatments consisted of i) basal diets (corn-wheat-soybean meal based diets without multi-enzyme and phytase), ii) basal diets with phytase (0.05%), iii) basal diets with exogenous multi-enzyme (0.05%), and iv) basal diets with exogenous multi-enzyme including phytase (0.05%). A total of 480 broiler chickens (Ross 308 - one day old) were weighed and allotted to thirty-two cages (15 birds per cage), and chicks were randomly allocated to four dietary treatments.ResultsThe body weight gain and feed conversion rate were improved by supplementation of exogenous multi-enzyme containing phytase during the finisher period (p<0.05). The birds fed diets with exogenous multi-enzyme containing phytase had a significantly greater digestibility of dry matter, gross energy, crude protein, calcium, and phosphorus compared with birds fed non-supplemented diets (p<0.05). The chickens fed diets with exogenous multi-enzyme containing phytase showed a higher concentration of Ca and P in the serum (p<0.05). The population of Lactobacillus spp., Escherichia coli, and Clostridium were not affected in the ileum and cecum of chickens fed enzyme-supplemented diets. The dietary supplemental exogenous multi-enzyme containing phytase showed a significant improvement in villus height, crypt depth, and villus height and crypt depth ratio, compared to basal diets or dietary supplemental phytase (p<0.05).ConclusionThe supplementation of the exogenous multi-enzyme containing phytase synergistically improved the growth performance, nutrients digestibility, and villus height of the small intestine of broiler chickens fed a corn-wheat-soybean meal based diets.

THE EFFECT OF PROPIONIC ACID ADDITION IN POULTRY DIETS ON THE INTERNAL ORGANS OF BROILER CHICKENS

This study aims to determine the effects of adding propionic acid in the poultry diets on the internal organs of broiler chickens. The livestock used were 180 broilers with Cobb strain. This study used a completely randomized design (CRD) consisting of 3 treatments and 6 replications.The treatments in this study consisted of: P0= commercial feed without propionic acid addition; P1= commercial feed with addition of 0.5%propionic acid; and P2= commercial feed with 0.75% propionic acid. The parameters observed included live weight, spleen percentage, gizzardpercentage, liver percentage, and small intestine length. The results showed that the addition of propionic acid in the broiler feed had a significant effect (P0.05) on the live weight and had no significant effect (P0.05) on the percentage of spleen, percentage of gizzard, percentage of liver, and small intestine length. The conclusion of this study was that the addition of propionic acid in poultry feed at a dose of 0.75% did not negatively affect the internal organs and the length of the small intestine of broiler chickens.

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.

Pengaruh Zona Penempatan Berbeda pada Closed House terhadap Mikroklimatik Amonia, Ukuran Relatif Organ Limfoid, Kelenjar Tiroid, dan Usus Halus Ayam Broiler

Tujuan dari penelitian ini untuk mengetahui pengaruh zona penempatan yang berbeda pada closed house terhadap mikroklimatik amonia, ukuran relatif organ limfoid, kelenjar tiroid dan usus halus ayam broiler. Materi yang digunakan dalam penelitian yaitu ayam broiler sebanyak 360 ekor yang diambil dari populasi 11.000 ekor dengan bobot badan awal 44,8 ± 1,66 gram. Rancangan yang digunakan adalah Rancangan Acak Kelompok dengan 4 perlakuan dan 6 kelompok sehingga terdapat 24 unit percobaan dan masing-masing unit terdapat 15 ekor. Perlakuan yang diberikan adalah T1 = zona 1 ; 0 m dari inlet, T2 = zona 2 ; 15 m dari inlet, T3 = zona 3 ; 30 m inlet, T4 = zona 4 ; 45 m dari inlet. Parameter yang diamati yaitu mikroklimatik amonia pada zona berbeda, bobot organ limfoid, kelenjar tiroid, panjang dan bobot usus halus ayam broiler. Hasil analisis ragam yang telah dilakukan dapat diketahui bahwa perubahan mikroklimatik amonia pada zona penempatan berbeda tidak berpengaruh nyata (P&gt;0,05) terhadap ukuran relatif organ limfoid, panjang dan bobot usus halus ayam broiler. Simpulan dari penelitian ini adalah zona penempatan berbeda dalam kandang closed house yang diikuti dengan perubahan mikroklimatik amonia tidak mempengaruhi ukuran relatif organ limfoid, kelenjar tiroid dan usus halus ayam broiler.

PEMANFAATAN TEPUNG DAUN APU-APU (Pistia stratiotes) DALAM RANSUM BASAL TERHADAP ORGAN PENCERNAAN AYAM RAS PEDAGING

Water lettuce meal (Pistia stratiotes) is the weed that has potential as animal feed due to it contain high crude protein and energy metabolism. The aims of this study wasto determine the weight and length of digestive organs including proventriculus, ventriculus, small intestine in broiler chicken given of water lettuce meal (WLM) in ratios. The research design of this study was a completely randomized design (CRD) with five treatments and four replications. The treatments consisted of T0 (commercial feed without WLM), T1 (ration with 0% WLM), T2 (ration with 5% WLM), T3 (ration with 10% WLM) and T4 (ration with 15% WLM). The experimental animal used were broiler DOC until the age of 35 days old were kept in 20 cages and each cage consisted of 3 broiler chickens. The parameters measured were proventriculusweight, ventriculus weight, small intestine weight and length of the small intestine. The results showed that there was no significant effects among treatments on all parameters. The conclusions of the study that the use of indicate that WLM could be used as feed up to 15% in ration without affecting their the proventriculus weight, ventrikulus weight, small intestine weight and length small intestineinbroiler chickens.

Molecular cloning, tissue distribution and the expression of cystine/glutamate exchanger (xCT, SLC7A11) in different tissues during development in broiler chickens.

The cystine/glutamate exchanger (xCT, SLC7A11) is a component of the system Xc amino-acid antiporter that is able to export glutamate and import cysteine into cells. The xCT amino acid exchanger has received a lot of attention, due to the fact that cysteine is an essential substrate for the synthesis of glutathione (GSH), an endogenous antioxidant in cells. The objective of this research was to clone the full-length cDNA of chicken xCT, and to investigate the gene expression of xCT in different tissues, including intestinal segments of broiler chickens during development. The full-length cDNA of chicken xCT (2,703 bp) was obtained from the jejunum by reverse transcription-PCR and sequenced. Homology tests showed that chicken xCT had 80.4%, 80.2%, and 71.2% homology at the nucleotide level with humans, cattle, and rats, respectively. Likewise, amino acid sequence analysis showed that chicken xCT protein is 86.4%, 79.3%, and 75.6% homologous with humans, cattle, and rats, respectively. Additionally, phylogenetic analysis indicated that chicken xCT genes share a closer genetic relationship with humans and cattle, than with rats. The chicken xCT protein has 12 transmembrane helixes, 6 extracellular loops, and 5 intracellular loops. The mRNA of xCT was detected in all tissues, including intestinal segments, in which the mRNA expression of xCT was significantly higher (P < 0.05) within the colon, compared to the jejunum and ileum. During development, a linear pattern of changes regarding the levels of the xCT mRNA was found, indicating that there was an abundance of xCT within the duodenum (P < 0.05). Furthermore, there were changes of the xCT mRNA abundance in the colon during development, which displayed linear and cubic patterns (P < 0.05). These results indicated that xCT is widely expressed both in intestinal segments, as well as other organs that are not associated with nutrient absorption. Further investigation is needed to characterize the functional relevance of xCT activity in oxidative stress and inflammation in the small intestine of broiler chickens.

Microstructure of the small intestine in broiler chickens fed a diet with probiotic or synbiotic supplementation.

The aim of the study was to determine the effect of dietary supplementation of a probiotic and a synbiotic on the morphometric parameters of the small intestine of broiler chickens. The experiment was conducted on three hundred sixty, one-day-old female Ross 308 chicks, which were randomly selected from 20,000 birds and divided into three treatment groups (n=120) with ten replicates per treatment. The control group (C) was fed a commercial diet, the probiotic group (PRO) was fed the same diet with an added 1% of the probiotic Lavipan® (Lactococcus lactis, Carnobacterium divergens, Lactobacillus casei, Lactobacillus plantarum and Saccharomyces cerevisiae), and the synbiotic group (SYN) was fed the commercial diet with an added synbiotic: 0.8% of the prebiotic RFO (extracted from lupin seeds) and 1% Lavipan®. According to the manufacturer's data, apart from the typical probiotic action,microorganisms contained in the preparation release anti-bacterial substances (hydrogen peroxide and bacteriocins) and, therefore, are antagonistic towards pathogenic bacteria present in the gut of animals. Supplementation took place in the first seven days of rearing, and all birds had ad libitum access to water and feed during the 42days of the experiment. On the last day, all birds were slaughtered and samples from three segments of the small intestine were taken. Villi area, height, width and crypt depth ratios were read using Multiscan software. Synbiotic supplementation increased the BWG of broilers from first to tenth day of rearing, compared to the control group. The PRO group had improved villi morphometric parameters of the duodenum. In the jejunum and ileum, both bioactive substances improved villus width and villus surface area. Crypts were deeper in the small intestine of birds supplemented with bioactive substances, which allows greater renewal of the villi. As expected, the intestinal morphometric parameters of broiler chickens benefited from bioactive substance supplementation.

Heat stress, Eimeria spp. and C. perfringens infections alone or in combination modify gut Th1/Th2 cytokine balance and avian necrotic enteritis pathogenesis

Information on the dynamics of the chicken immune system during bacterial or parasite challenge in the presence or absence of stressful situations may provide a better understanding of the complex mechanisms behind these diseases. Necrotic enteritis (NE) had been controlled previously by the proper use of antimicrobial agents; however, more recently, NE has reemerged in many countries. The imposed restrictions on antimicrobial use and/or the intensive productive programs implemented by producers are challenges the birds, leading to large host adaptive responses that in many instances are like those elicited by stressors. This study analyses the effects of heat stress on Th1/Th2 cytokine balance, pathological features, and Toll-like receptor expression in the small intestine of broiler chickens infected with Clostridium perfringens type A in the presence or absence of Eimeria spp. co-infection. This co-infection model was experimentally used because it reproduces the findings commonly observed in the field during avian NE. For this purpose, broiler chickens infected with C. perfringens and/or Eimeria spp. were reared in isolator chambers subjected or not to heat stress intermittently. It was observed that heat stress directs the expression of Th2-type cytokines, increases Toll-like receptor 4 expression in the intestine and reduces the disease severity induced by Eimeria spp. and C. perfringens infections alone or in combination, most likely as a consequence of stress-induced changes in brain-gut axis activity.

Effect of different cereal-based diets supplemented with multi-enzyme blend on growth performance villus structure and gene expression (SGLT1, GLUT2, PepT1 and MUC2) in the small intestine of broiler chickens

An experiment was conducted to evaluate the effect of corn, wheat and barley-based diets supplemented with COMBO® multi-enzyme (an enzyme blend with 1000 active unit of phytase and 480 active unit of glycanase per gram in form of powder) on physiological response of chickens. Growth performance (gain, feed intake, and feed conversion), villus structure (villus height, villus width, crypt depth) and expression of glucose and peptide transporters (SGLT1, GLUT2, PepT1) and mucin producer (MUC2) genes in the small intestine of chickens were measured. One-day old Ross 308 mixed broiler chickens (n = 625) were allocated to 5 treatments with 5 replicates, using a completely randomized design (CRD), statistical plan. The control diet produced the greatest live weight (2251.26 g) and the lowest live weight (2015.77 g), was for birds on the wheat diet (P < 0.01). Cumulative feed intake and the mean daily feed intake was the greatest for the barley + enzyme treatment (4392.37 g) and the lowest (4164.21 g) for the wheat treatment (P < 0.01). The birds of control diet had the lowest feed conversion (1.90), but wheat and barley diets had the highest value (2.06). The smallest crypt depth in the jejunum (95 μm) was associated with birds in the barley + enzyme treatment and the greatest crypt depth in the jejunum (116 μm) belonged to birds on the wheat treatment. Wheat and barley diets resulted in a reduced villus height but supplementation with a multi-enzyme blend resulted in an increased the villus height (P < 0.01). Barley and wheat treatments had the greatest expression of glucose transporter (1.85 and 1.78 for SGLT1, 1.80 and 1.72 for GLUT2 respectively), peptide transporter (2.82 and 2.50 for PepT1) and mucin producer (1.38 and 1.48 for MUC2) genes in the small intestine (P < 0.01). In conclusion, using economical diets of wheat and barley complement to a corn-soy based diet without multi-enzyme is likely to have adverse effects on growth performance, villus morphology, and gene expression of nutrient transporters in the small intestine.

Age, phosphorus, and 25-hydroxycholecalciferol regulate mRNA expression of vitamin D receptor and sodium-phosphate cotransporter in the small intestine of broiler chickens

Four experiments were conducted in this study. Experiment 1 was carried out to examine mRNA expressions of nuclear vitamin D receptor (nVDR), membrane vitamin D receptor (mVDR), and type IIb sodium-phosphate cotransporter (NaPi-IIb) in the small intestine of broiler chickens. Experiments 2, 3, and 4 were implemented to evaluate effects of age, non-phytate phosphorus (NPP), and 25-hydroxycholecalciferol (25-OH-D3) on mRNA expressions of nVDR, mVDR, and NaPi-IIb in the duodenum of chickens. Results showed that mRNA expression levels of nVDR and NaPi-IIb were highest in the duodenum of 21-day-old broilers, lower in the jejunum, and lowest in the ileum. By contrast, no differences in mRNA expression levels of mVDR were detected among the duodenum, jejunum, and ileum. Age quadratically affected mRNA expressions of nVDR, mVDR, and NaPi-IIb in the duodenum and 25-hydroxylase in the liver of 7- to 42-day-old broilers, with the highest levels observed at 21 d of age. By contrast, age linearly decreased mRNA expression level of 1α-hydroxylase in kidneys. Dietary NPP levels quadratically affected mRNA expression levels of nVDR and mVDR in the duodenum and 25-hydroxylase in the liver of 21-day-old broilers. The highest mRNA expression levels of nVDR and mVDR and lowest mRNA level of 25-hydroxylase were observed at 0.55% NPP. mRNA expression level of NaPi-IIb linearly declined when dietary NPP levels increased from 0.25 to 0.65%. Addition of 12.5μg/kg of 25-OH-D3 increased mRNA expression level of 1α-hydroxylase in kidneys and those of nVDR, mVDR, and NaPi-IIb in the duodenum of broilers compared with birds fed the diet without 25-OH-D3. These data indicate that mRNA expressions of nVDR and NaPi-IIb are highest in the duodenum, and the greatest mRNA levels of nVDR, mVDR, and NaPi-IIb are observed at 21 d of age. Dietary NPP levels quadratically increase mRNA expressions of nVDR and mVDR but linearly decrease NaPi-IIb mRNA level. 25-OH-D3 up-regulates the above gene transcription.

Responses in digestibilities of macro-minerals, trace minerals and amino acids generated by exogenous phytase and xylanase in canola meal diets offered to broiler chickens

Atypical diets based on canola meal (584 g/kg) and dextrose, supplemented with phytase and xylanase individually and in combination, were offered to 120 male Ross 308 broiler chicks with six replicates for each of the four treatments. The objective was to determine the effects of phytase and xylanase on the apparent digestibility coefficients of macro-minerals, trace minerals and amino acids along the small intestine of broiler chickens. The combination increased phosphorus digestibility by a two-fold factor (0.694 versus 0.324), calcium digestibility by a three-fold factor (0.527 versus 0.178), increased zinc from -0.141 to 0.324 and increased sodium digestibility coefficients from -1.402 to -0.359 in comparison to the control diet. Similarly, phytase and xylanase in tandem generated better responses in the apparent ileal digestibility coefficients of amino acids. The enzyme combination significantly increased the digestibility of nine essential amino acids by from 5.47% (methionine) to 35.4% (threonine), and seven non-essential amino acids by from 13.9% (glutamic acid) to 32.9% (proline). The better responses in apparent ileal digestibilities of phosphorus, calcium, sodium, zinc and five other trace minerals in broiler chickens offered the combination diet was confounded by its higher enzyme recovery activities in comparison to the individual supplemented diets and the study may suggest that the inclusions of phytase and xylanase in tandem should be considered in diets containing canola meal for broiler chickens.