Chicken Small Intestine Research Articles

Susceptibility of chickens (Gallus gallus domesticus) to Trichinella patagoniensis

Trichinella spp. is a genus of parasites that is widespread all over the world. In Argentina, T. spiralis was for years the only species involved in human and animal outbreaks. During the last decade, T. patagoniensis, a new Trichinella species, was discovered in Argentina. Up to now, this species has only been found in cougars (Puma concolor). Experimental infections in pigs, cats, mice and rats with this new genotype showed that cats and mice were the most susceptible hosts. The aim of the present work was to evaluate the susceptibility of chickens to infection with T. patagoniensis. In order to study the intestinal and muscular phase, and the histopathological changes, 27 Leghorn chickens were inoculated per os with 1000 muscle larvae of T. patagoniensis and were euthanized on days 4, 5, 6, 7, 11, 14, 21, 28 and 35. Adult worms of T. patagoniensis were recovered from the small intestine of chickens up to day 14p.i. Gross examination of small intestine showed a moderate congestive appearance. Microscopically, an inflammatory response with lymphocytes and eosinophils in lamina propria, slight hyperemia, oedema and some haemorrhagic areas were detected. Lesions observed in chickens were similar to those described in different animal species during the intestinal phase. No muscular larvae were recovered from the muscle samples. These results suggest that T. patagoniensis is not capable to complete its entire life cycle in chickens.

The feed contaminant deoxynivalenol affects the intestinal barrier permeability through inhibition of protein synthesis.

Deoxynivalenol (DON) has critical health effects if the contaminated grains consumed by humans or animals. DON can have negative effects on the active transport of glucose and amino acids in the small intestine of chickens. As the underlying mechanisms are not fully elucidated, the present study was performed to delineate more precisely the effects of cycloheximide (protein synthesis inhibitor, CHX) and DON on the intestinal absorption of nutrients. This was to confirm whether DON effects on nutrient absorption are due to an inhibition of protein synthesis. Changes in ion transport and barrier function were assessed by short-circuit current (Isc) and transepithelial ion conductance (Gt) in Ussing chambers. Addition of D-glucose or L-glutamine to the luminal side of the isolated mucosa of the jejunum increased (P < 0.001) the Isc compared with basal conditions in the control tissues. However, the Isc was not increased by the glucose or glutamine addition after pre-incubation of tissues with DON or CHX. Furthermore, both DON and CHX reduced Gt, indicating that the intestinal barrier is compromised and consequently induced a greater impairment of the barrier function. The remarkable similarity between the activity of CHX and DON on nutrient uptake is consistent with their common ability to inhibit protein synthesis. It can be concluded that the decreases in transport activity by CHX was evident in this study using the chicken as experimental model. Similarly, DON has negative effects on the active transport of some nutrients, and these can be explained by its influence on protein synthesis.

Influences of protein ingestion on glucagon‐like peptide (GLP)‐1‐immunoreactive endocrine cells in the chicken ileum

Influences of a specific dietary nutrient on glucagon-like peptide (GLP)-1-containing cells in the chicken intestine are not yet clear. Significance of dietary protein level on GLP-1-containing cells in the chicken ileum was investigated. Chickens fed control or experimental diets of varying protein levels were examined using immunohistochemical and morphometrical techniques. We show that the protein ingestion had an impact on the activities of GLP-1-immunoreactive cells in the chicken ileum. Weight gains declined with decreasing dietary crude protein (CP) levels, but no significant differences were detected in the daily feed intake and villous height. GLP-1-immunoreactive cells with a round or oval shape were frequently observed in the lower CP level groups (4.5% and 0%). Frequencies of occurrence of GLP-1-immunoreactive cells were 41.1 ± 4.1, 38.5 ± 4, 34.8 ± 3.1 and 34.3 ± 3.7 (cells/mm(2) , mean ± SD) for dietary CP level of 18%, 9%, 4.5% and 0% groups, respectively and significant differences were recognized between the control and lower CP level groups (P<0.05). Multiple regression analysis indicated a significant correlation between the daily protein intake and frequencies of occurrence of GLP-1-immunoreactive cells. The protein ingestion is one of the signals that influence GLP-1-containing cells in the chicken small intestine.

Distribution of Glucagon-Like Peptide (GLP)-2-Immunoreactive Cells in the Chicken Small Intestine: Antigen Retrieval Immunohistochemistry

ABSTRACTAn antigen retrieval method for immunohistochemical staining of glucagon-like peptide (GLP)-2-immunoreactive cells was investigated in the chicken small intestine. GLP-2-immunoreactive cells were observed as open-typed endocrine cells in the villous epithelium and crypts on both antigen retrieval agent-treated and untreated preparations. No obvious differences were detected in morphological features of GLP-2-immunoreactive cells between treated and untreated preparations. The frequencies of occurrence of GLP-2-immunoreactive cells, however, were significantly different in treated and untreated preparations: in the proximal and distal regions of jejunum and ileum obtained from untreated preparations, the frequencies of occurrence were 0.5 ± 0.2, 0.7 ± 0.1, 0.9 ± 0.2 and 1.5 ± 0.3, respectively (cell numbers per mucosal area: cells/mm2, mean ± SD), whereas those from treated sections were 14.7 ± 2.3, 19.8 ± 2.3, 23.5 ± 4.7 and 34.6 ± 4.9 cells/mm2, respectively. These data indicate that this antigen retrieval method is able to make immunoreactive GLP-2 available for detection and that GLP-2 may act as one of the common hormones secreted by L cells in the chicken small intestine.

Effects of breeder age and egg weight on morphological changes in the small intestine of chicks during the hatch window

1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window.2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed.3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks.4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.

Effects of epimedium polysaccharide-propolis flavone oral liquid on mucosal immunity in chickens

A previous study found that epimedium polysaccharide (EP)-propolis flavonoid (PF) injection (EPI) produced reliable immunoenhancement. In this study, we investigate the effects of EP-PF oral liquid (EFO) on mucosal immunity in the chicken small intestine while using EPI, EP and PF as controls. Groups of fourteen-day-old chickens were given EFO orally at one of the three doses when they were vaccinated with ND vaccine. On days 7, 21 and 35 after the first vaccination, six chickens were selected randomly from each group for measurements of the sIgA and IL-17 contents of the washing liquors of the duodenum and jejunum, counts of the lymphocytes in the duodenal endothelium and counts of the IgA+ cells in the jejunal endothelium and cecum tonsil. The results indicated that EFO significantly promoted the secretion of sIgA and IL-17 and increased the numbers of lymphocyte and IgA+ cells. Furthermore, EFO was more efficient than EPI at the high and medium doses. These findings indicate that EPO may enhance intestinal mucosal immunity and may be exploited as an oral immunopotentiator.

The Influence of Restricted Feeding on Glucagon‐Like Peptide‐1 (GLP‐1)‐Containing Cells in the Chicken Small Intestine

The influence of restricted feeding on the distribution of glucagon-like peptide-1 (GLP-1)-containing endocrine cells in the chicken small intestine was investigated using immunohistochemical and morphometrical techniques. This study demonstrated that the restricted feeding had an influence on the activity of GLP-1-immunoreactive cells in the chicken small intestine. There were differences in the localization and the frequency of occurrence of GLP-1-immunoreactive cells in the small intestine between control and restricted groups, especially 25% feed supply group provided with 25% of the intake during the adapting period. GLP-1-immunoreactive cells in the control chickens were mainly located in epithelium from crypts to the lower part of intestinal villi. Those in restricted groups, however, tended to be located from crypts to the middle part of intestinal villi. The frequency of occurrence of GLP-1-immunoreactive cells was lowest in the control group, medium in 50% feed supply group and highest in 25% feed supply group at each intestinal region examined in this study, that is, increased with the advancement of restricting the amount of feed supply. These data show that the quantity of food intake is one of signals that have an influence on the secretion of GLP-1 from L cells in the chicken small intestine.

The effect of dietary supplementation of nitric oxide donor and inhibitor on nNOS expression in and motility of the small intestine of broilers

We investigated the effect of dietary supplementation of sodium nitroprusside (SNP), a nitric oxide (NO) donor, and N-nitro-L-arginine methyl ester (L-NAME), a NO inhibitor, on neuronal nitric oxide synthase (nNOS) expression in and motility of small intestinum in broilers. A total of 560, one-day-old Ross 308 hybrid mixed sex broiler chicks were divided randomly into one control and seven treatment groups for a 42 day feeding trial including starter phase (0–21 days) and grower phase (22–42 days). The control group was fed a basal diet and the experimental groups were the fed basal diet supplemented with 25, 50, 100 and 200 mg/kg SNP and 25, 50 or 100 mg/kg L-NAME. Ten chickens from each group were sacrificed to collect samples on days 21 and 42. The expression patterns of nNOS immunoreactivity in nerve fibers were determined by immunohistochemistry. In the contractility studies, longitudinal isolated strips of duodenum, jejunum and ileum were treated with 10−5 M L-arginine and 10−4 M SNP. Immunohistochemistry revealed that nNOS expression was not detectable in the duodenum or ileum of either the control or experimental groups. On the other hand, nNOS immunoreactivity in the jejunum control group showed a strong reaction on day 21, but the reaction was weak on day 42. nNOS expression clearly was suppressed on day 21 by the diet supplemented with L-NAME, while the diet supplemented with SNP stimulated nNOS expression on day 21. Contractility experiments revealed that spontaneous contractility of isolated strips of duodenum, jejunum and ileum showed no significant difference among groups. Spontaneous contractions of all strips were inhibited by L-arginine and SNP in all groups. The percentage inhibition rate of spontaneous contractions of jejunum application on days 21 and 42 after L-arginine decreased in the group supplemented with 100 mg/kg L-NAME. The percentage inhibition rate on day 21 after SNP application decreased in both groups that received 50 and 100 mg/kg L-NAME. We demonstrated the expression pattern of nNOS in nerve fibers in jejunum of broiler chickens. Contractility studies revealed that the NOS-NO pathway may play a role in smooth muscle contraction of small intestine of chickens. Feeding strategies that supplement NO donor and NO inhibitor can be of physiological importance to small intestine motility owing to alteration of nNOS expression in the jejunum.

Ultrastructural Study on Colocalization of Glucagon-Like Peptide (GLP)-1 with GLP-2 in Chicken Intestinal L-Cells

ABSTRACTColocalization of glucagon-like peptide (GLP)-1 with GLP-2 in L-cells was investigated in the chicken ileum by using double immunofluorescent and immunocytochemical techniques. Ultrastructural features of L-cells were also clarified in this study. L-cells showing immunoreactivity for both GLP-1 and GLP-2 were distributed in the whole ileum. They showed comma-like or flask-like shape and were located in epithelium of crypts and lower part of intestinal villi. L-cells showing GLP-1-immunoreactivity only were found in epithelium of lower and middle parts of intestinal villi. Transmission electron microscopy indicated that L-cells identified by colloidal gold-labeled immunocytochemistry were covered apically with microvilli, open-type and contained many secretory granules in their perikarya. These secretory granules without halo were round to oval in shape and showed moderate electron density. The longest and shortest diameters of secretory granules were 355 ± 62 nm (mean ± SD) and 287 ± 48 nm, respectively. Double labeling immunocytochemistry using two different sizes of particles (6 and 12 nm in diameter) of colloidal gold revealed that GLP-1 colocalized with GLP-2 in the same secretory granules. This study advances new morphological data about the endocrine system of the chicken small intestine.

The toxicity of Fusarium mycotoxin deoxynivalenol in poultry feeding

Deoxynivalenol (DON) is prevalent worldwide in crops used for food and feed production. The presence of mycotoxins in poultry feeds is a significant factor contributing to financial losses in animal industries. DON causes losses in livestock production and poses a health problem to livestock and humans consuming contaminated cereal products. Although DON is one of the least acutely toxic trichothecenes, it should be treated as an important food safety issue because it is a very common contaminant of grains. Poultry respond to increasing dietary DON concentrations with a reduction in productivity only at high levels (above 5 mg/kg) but there is no evidence of a clear dose-response relationship. Poultry fed low to moderate doses are able to recover from initial weight losses, while higher doses induce more long-term changes in feeding behaviour. At low dosages of DON, haematological, clinical and immunological changes are transitory and decrease as compensatory/adaptation mechanisms are established. The exposure to higher dose levels of DON are mainly expressed as severe reductions in body weight and impaired resistance to infection, particularly bacterial infection. Common symptoms of acute toxicity of DON are nausea, vomiting, dermal irritation and lesions, haemorrhagic lesions and pathological changes in the haemopoietic organs.The capacity of DON to alter normal gut and immune function has been of particular interest. One important aspect of DON toxicity is an injury of the gastrointestinal tract. It was found that DON had an influence on intestinal nutrient absorption and the intestinal morphology of chickens, especially in the duodenum and jejunum, as evidenced by shorter and thinner villi. DON decreases glucose and amino acid absorption in the chicken's small intestine in vivo and in vitro and this effect is apparently mediated by the inhibition of the sodium D-glucose co-transporter. It was found that immune function decreased in broiler Leghorn chicks that were fed DON-contaminated diets. It induces changes in the hematopoietic system of chicks and alters immune response, whereas, DON impairs mitogen-induced proliferation of lymphocytes. The feeding of DON-contaminated grains decreased serum antibody titers against Newcastle disease virus (NDV) and infectious bronchitis (IB) in laying hens and broilers. The impact of DON on the immune system and gastrointestinal tract are important to define the maximum tolerable levels of DON in animal feedstuffs. The purpose of this review is to summarise the information to date regarding the toxicological and immunological effects of DON on poultry.

Different phosphate transport in the duodenum and jejunum of chicken response to dietary phosphate adaptation.

Intestinal phosphate (Pi) absorption across the apical membrane of small intestinal epithelial cells is mainly mediated by the type IIb Na-coupled phosphate co-transporter (NaPi-IIb), but its expression and regulation in the chicken remain unclear. In the present study, we investigated the mRNA and protein levels of NaPi-IIb in three regions of chicken small intestine, and related their expression levels to the rate of net phosphate absorption. Our results showed that maximal phosphate absorption occurs in the jejunum, however the highest expression levels of NaPi-IIb mRNA and protein occurs in the duodenum. In response to a low-Pi diet (TP 0.2%), there is an adaptive response restricted to the duodenum, with increased brush border membrane (BBM) Na-Pi transport activity and NaPi-IIb protein and mRNA abundance. However, when switched from a low- (TP 0.2%) to a normal diet (TP 0.6%) for 4 h, there is an increase in BBM NaPi-IIb protein abundance in the jejunum, but no changes in BBM NaPi-IIb mRNA. Therefore, our study indicates that Na-Pi transport activity and NaPi-IIb protein expression are differentially regulated in the duodenum vs the jejunum in the chicken.

A diet naturally contaminated with the Fusarium mycotoxin deoxynivalenol (DON) downregulates gene expression of glucose transporters in the intestine of broiler chickens

This study was conducted to determine whether a diet with moderate contamination of Fusarium mycotoxin deoxynivalenol (DON) alters the glucose absorption and whether this might be linked to altered SGLT-1 and GLUT-2 mRNA expression in the small intestine of chickens. Forty-five 1-d-old broiler chickens were randomly assigned into three groups (15 per group, 2–3 birds per pen). The birds in treated groups were fed a diet naturally contaminated with DON (1 and 5mg/kg). After 5weeks, one bird per pen from 6 pens was randomly selected from each group to assess glucose transport in small intestinal tissues (Ussing chamber). The mRNA expression of the Na+-dependent glucose transporter SGLT-1 and the facilitative GLUT-2 were assayed by real-time PCR to clarify genomic regulation of glucose transport by DON. The morphology of the jejunal mucosa was also investigated in order to assess non-specific effects of DON. The results showed that DON significantly inhibited glucose-induced currents in jejunal tissues and decreased the expression of SGLT-1 and GLUT-2 mRNA for both DON-supplemented groups (P<0.01). The mRNA of SGLT-1 was down-regulated in duodenal and jejunal tissues of both DON-supplemented groups (P<0.01). GLUT-2 mRNA was down-regulated only in duodenal tissues for both DON-supplemented groups. Additionally, DON at both concentrations altered the small intestinal morphology by decreasing villi length and the absorptive surface area (P<0.01). We conclude that DON contaminated diet suppresses the mRNA abundance and activity of intestinal glucose transporters in chicken intestine under practically relevant feeding conditions. This further suggests that DON has indeed a specific inhibitory effect on glucose transport in addition to a concurrent decrease of intestinal surface area even at low to moderate dietary concentrations.

Proteomic Evaluation of Chicken Brush-Border Membrane during the Early Posthatch Period

The chicken small intestine undergoes structural and functional changes during the early posthatch period to accommodate the transition from a lipid-rich diet inside the egg to a carbohydrate- and protein-based diet. Many of the enterocyte brush-border membrane-associated proteins responsible for mediating changes in nutrient utilization are unknown. The objective of this study was to conduct a proteomic analysis of chicken small intestine during the early posthatch period. We isolated brush-border membrane at day of hatch and days 1, 3, 7, and 14 posthatch from the small intestine of 2 genetic lines of broilers that differ in growth performance, and performed 2D gel-electrophoresis. A total of 1693 spots were analyzed by matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry (MALDI-TOF/TOF). In total, 132 different proteins were identified and grouped according to biological function. Of these, there were 10 nutrient transporters, 9 digestive enzymes, and 17 proteins associated with cytoskeletal structure and microvilli organization. The remaining proteins were classified as basolateral membrane (3), endosomal/membrane trafficking (8), signaling (14), metabolic (33), degradative (5), stress-related (5), protein synthesis machinery/mitochondria/nucleus (19), immunologic (1), or unknown (8). Of the spots in which proteins were identified, there were 10 that showed an effect of broiler genetic line on protein spot density (P<0.001) and 19 spots showing a correlation of broiler genetic line x age (P<0.001). Identification of brush-border membrane-associated proteins is an important step in furthering our understanding of digestion and absorption in the chicken.

Pituitary adenylate cyclase-activating peptide (PACAP) immunoreactivity distribution in the small intestine of the adult New Hampshire chicken

We conducted a study in which we demonstrated by means of immunoperoxidase and immunofluorescence methods the presence of pituitary adenylate cyclase-activating peptide 38 (PACAP-38) immunoreactivity in the small intestine of adult New Hampshire chickens and its co-localization with VIP. In particular we describe for the first time the presence of PACAP-positive cells in the epithelium of crypts and villi. Using double immunostaining, we observed that these two peptides were widely co-localized in the nerve structures of duodenum and jejunum with the exception of the ileum, where we noticed a faint co-localization regarding the nerve fibers of the lamina propria of the villi. Furthermore, the two peptides were occasionally co-stored in the epithelial cells of the mucosa. Our findings suggest that in the chicken small intestine, PACAP can be considered, not only as a neuromodulator released by nerve elements, but also as a gut hormone secreted by endocrine cells, and it appears likely to have a role in the regulation of important intestinal physiological functions.

Proteomic evaluation of chicken brush‐border membrane during the early post‐hatch period

Many of the proteins responsible for mediating changes in nutrient assimilation in the chicken small intestine are uncharacterized. The objective of this study was to conduct a proteomic analysis of the chicken brush‐border membrane. We isolated brush‐border membrane from broiler small intestine at day of hatch and days 1, 3, 7 and 14 post‐hatch, and performed 2D‐electrophoresis. A total of 1,693 spots were analyzed by matrix‐assisted laser desorption/ionization‐tandem time‐of‐flight mass spectrometry (MALDI‐TOF/TOF). A total of 256 unique proteins were identified and grouped according to biological function. Of these, there were 12 nutrient transporters, 17 digestive enzymes and 47 proteins associated with cytoskeletal structure and microvilli organization. The remaining proteins were classified as tight junction (3), basolateral membrane (3), endosomal/membrane trafficking (10), signaling (34), metabolic (41), degradative (12), stress‐related (10), protein synthesis machinery/mitochondria/nucleus (29), immunologic (6), unknown (14), or other (18). Identification of brush‐border membrane‐associated proteins is an important step in furthering our understanding of digestion and absorption in the chicken. Further analysis of proteins with unknown function may lead to elucidation of novel pathways involving nutrient utilization.

Animal Feed Additive and the Effect of the Fusarium Toxin Deoxynivalenol on the Electrophysiological Measurement of Transepithelial Ion Transport of Young Chickens with Ussing Chamber Technique

The presence of mycotoxins in poultry feeds is a significant factor for financial losses to animal industries. Ingestion of mycotoxin-contaminated feed by chickens causes injury to the gastrointestinal tract. DON has negative effects on the active transport of some nutrients in the small intestine of chickens. We tested the hypothesis that prefeeding with probiotic (Eubacterium sp.) or inulin, as a prebiotic, would attenuate these effects. Whereas, there is evidence in chicken that dietary supplementation with probiotic and prebiotic affect the intestinal microflora, increased the paracellular permeability and increased the villus length and villus area of the small intestine. The question of whether these changes affect the toxic effects of DON on the electrogenic glucose transport in the chicken intestine or not needs to be clarified. Therefore, an experiment was conducted to study the effects of DON in the presence or absence of dietary (Eubacterium sp.) or inulin on the electrophysiological response of the gut to glucose. The results indicated that in the absence of clinical signs and without impaired performance, DON appeared to alter the gut function of broilers. The addition of Eubacterium sp. may be useful in counteracting the toxic effects of DON on intestinal glucose transport. But, the dietary inulin supplementation of the broilers improved the glucose transport in the presence of DON and kept it at normal levels.

A nutritional approach for the management of deoxynivalenol (DON) toxicity in the gastrointestinal tract of growing chickens.

It has been shown that DON has negative effects on the active transport of some nutrients in the small intestine of chickens. The plausible interactions between food contaminants and natural components could be high. The present study investigated the effects of DON on the presence or absence of dietary inulin on the electrophysiological response of the gut to glucose. Ussing chamber studies were conducted with isolated jejunal epithelia at the age of 35 days. Electrophysiology of the epithelia was recorded and the changes of the short-circuit current (Isc) were determined. The addition of d-glucose on the luminal side of the isolated mucosa increased (P < 0.05) the Isc in the control group and inulin supplemented group. The oligosaccharides did not increase glucose absorption in young healthy chickens compared with the controls. In the second experiment, after preincubation of tissues with DON, the addition of glucose did not increase the Isc in jejunum and colon in the control group (P > 0.05). However, in the dietary inulin supplemented group in both jejunum and colon, the addition of glucose after preincubation of tissues with DON increased the Isc, suggesting that the dietary inulin supplementation of the broilers regulated and improved the glucose absorption in the presence of DON and kept it at normal levels.

Gene Expression of Nutrient Transporters in the Small Intestine of Chickens from Lines Divergently Selected for High or Low Juvenile Body Weight

Nutrient transporters in the small intestine are responsible for dietary nutrient assimilation; therefore, the expression of these transporters can influence overall nutrient status as well as the growth and development of the animal. This study examined correlated responses to selection in the developmental gene expression of PepT1, EAAT3, SGLT1, and GLUT5 in the small intestine of chickens from lines divergently selected for 48 generations for high (HH) or low (LL) 56-d BW and their reciprocal crosses (HL and LH). Duodenum, jejunum, and ileum were collected from male and female chicks on embryonic d 20, day of hatch with no access to feed, and d 3, 7, and 14 posthatch. Total RNA was extracted, and nutrient transporter expression was assayed by real-time PCR using the relative quantification method. In comparing male and female HH and LL chicks, there was a mating combination × age × sex interaction for PepT1 expression (P < 0.001), a main effect of sex for EAAT3 (P < 0.05) and SGLT1 (P < 0.001) expression, and an age × sex interaction for SGLT1 expression (P < 0.001). These results demonstrate a sexual dimorphism in the capacity to absorb nutrients from the intestine, which has implications for the poultry industry with regard to diet formulations for straight-run and sex-separate grow-out operations. Results from comparing male LL, LH, HL, and HH chicks indicate that selection for high or low juvenile BW may have influenced the gene expression profiles of these nutrient transporters in the small intestine, which may contribute to the overall differences in the growth and development of these lines of chickens.

The Impact of the Fusarium Toxin Deoxynivalenol (DON) on Poultry

Deoxynivalenol (DON), a trichothecene, is prevalent worldwide in crops used for food and feed production. The presence of mycotoxins in poultry feeds is a significant factor for financial losses to animal industries. Although DON is one of the least acutely toxic trichothecenes, it should be treated as an important food safety issue because it is a common contaminant of grains. Special care must be taken in so-called “Fusarium years”. As poultry is regarded to be less sensitive to DON compared to other species it is suspected to divert the infected cereal batches to poultry feeding. This review focuses on the ability of DON to induce toxicologic and immunotoxic effects in chickens. Chickens and laying hens respond to increasing dietary DON concentrations with a reduction in productivity only at high levels above 5mg/kg but there is no clear evidence of a dose-response relationship. The main effect at low dietary concentrations appears to be a reduction in food consumption (anorexia), while higher doses induce severe reduction in weight and impaired resistance to infection, particularly bacterial infection. One important aspect of DON toxicity is injury to the gastrointestinal tract. DON has an influence intestinal morphology of chickens, especially in the duodenum and jejunum, as evidenced by shorter and thinner villi. Additionally, DON decreased the intestinal nutrients absorption (glucose and amino acid) in the chicken small intestine in vivo and In vitro. The capacity of DON to alter normal immune function has been of particular interest. There is extensive evidence that DON impairs the immune function in broiler and Leghorn chicks. DON induced changes in the haematopoietic system of chicks and altered the mitogen-induced proliferation of lymphocytes. The feeding of DON contaminated grains decreases serum antibody titers against Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) in laying hens and broilers. Other effects include superinduction of cytokine production by T helper cells (In vitro) and activation of T cells to produce a proinflammatory cytokine. To what extent the elevation of cytokines contributes to metabolic effects such as decreased feed intake remains to be established. Further toxicological studies on the impact of DON in the immune system and gastrointestinal tract of poultry are warranted.

Partial Na+ Dependence of dl-2-Hydroxy-4-(Methylthio)Butanoic Acid Uptake in the Chicken Small Intestine

Methionine hydroxy analogue dl-2-hydroxy-(4-methylthio)butanoic acid (HMTBA) is commonly used as a supplemental source of Met in commercial animal diets. To better understand the uptake of this analogue by the chicken intestine, the aim of the present study was to assess the contribution of Na+ gradient on HMTBA accumulation in everted sacs of the chicken small intestine (duodenum, jejunum, and ileum). In the presence of an H+ gradient, uptake was lower in the absence of Na+ along the chicken small intestine, although no significant differences were detected in the duodenum. In contrast, in the absence of an H+ gradient, no significant differences were detected between the 2 Na+ conditions. In conclusion, the observed relationship between Na+ and H+ dependence indicates the participation of the apical Na+/H+ exchanger in HMTBA uptake in the chicken small intestine.