A microbial muramidase improves growth performance and reduces inflammatory cell infiltration in the intestine of broilers chickens under Eimeria and Clostridium perfringens challenge.

The objective of the present studies was to evaluate muramidase (MUR) supplementation in broilers under Eimeria and/or Clostridium perfringens challenge. For this, 2 experiments were conducted. Experiment 1. A total of 256 one-day old male Cobb 500 chicks were placed in battery cages in a completely randomized design, with 5 treatment groups, 7 replicate cages per treatment and 8 birds per cage. The treatments were: nonchallenged control (NC), challenged control (CC), CC + MUR at 25,000 or 35,000 LSU(F)/kg, and CC + Enramycin at 10 ppm (positive control-PC). Challenge consisted of 15× the recommended dose of coccidiosis vaccine at placement, and Clostridium perfringens (108 CFU/bird) inoculation at 10, 11, and 12 d. Macro and microscopic evaluation, immunohistochemistry, and gene expression were evaluated at 7, 14, 21, and 28 d of age. Experiment 2. A total of 1,120 one-day old male Cobb 500 chicks were placed in floor pens with fresh litter in a completely randomized design, with 4 treatment groups, 8 replicate pens per treatment, and 35 birds per pen. The treatments were: Control, supplementation of MUR at 25,000 or 45,000 LSU(F)/kg, and a positive control (basal diet plus Enramycin). At 10, 11, and 12 d of the experiment all the birds were inoculated by oral gavage with a fresh broth culture of a field isolate Clostridium perfringens (0.5 mL containing 106 CFU/bird). It was observed that in Experiment 1 MUR supplementation reduced the infiltration of macrophages and CD8+ lymphocytes in the liver and ileum of infected birds, downregulated IL-8 and upregulated IL-10 expression. In Experiment 2, MUR linearly improved the growth performance of the birds, increased breast meat yield, and improved absorption capacity. MUR supplementation elicited an anti-inflammatory response in birds undergoing a NE challenge model that may explain the improved growth performance of supplemented birds.

Applying different morphometric intestinal mucosa methods and the correlation with broilers performance under Eimeria challenge.

The intestinal wall has on its surface, protrusions called villi that are responsible for the absorption of nutrients. Commonly, these structures have their dimensions measured to related more area surface with better absorption. However, the measurement of these villi neglects the inflammation and the presence of immature cells that increase the surface area but affect negatively the absorption and compromise the animal performance. The measurements of villi/crypt are traditional tools in animal research; however, they may overlook alterations that impact the mucosal functionality. This study aimed to compare the morphometry of the intestinal villi/crypt with the I See Inside (ISI) scoring methodology, exploring their correlation with zootechnical performance. Therefore, broilers were grouped as nonchallenged (NC) and challenged with Eimeria (CH) and jejunum samples were collected at 22 d for histological analysis. The same villi were submitted to the ISI methodology, which is based on the scoring of 8 parameters related to the inflammatory process, and the measurements of villus height (VH), villus width (VW), crypt depth (CD), crypt width (CW), VH:CD ratio and villi absorptive surface (VAS). The CH group presented higher ISI total score, VW, CD, CW and lower VH, VH:CD, and VAS in comparison to the NC group. While the villi/crypt morphometry did not exhibit correlations with performance, the presence of Eimeria oocysts and the ISI total score was positively correlated (P < 0.05) with the feed conversion ratio (FCR), demonstrating a statistical interaction between high ISI scores and worse performance. In conclusion, a larger villus is not related to better intestinal functionality when this enlargement is unleashed by the immune processes occurring inside. The scoring system that evaluates the type of alteration observed has a direct impact on the animal's zootechnical performance which is not observed with the single metric surface evaluation.

Effects of protected complex of biofactors and antioxidants on growth performance, serum biochemistry, meat quality, and intestinal antioxidant and immunomodulatory-related gene expressions of broiler chickens.

One-day-old male broiler chickens (Ross 308) were assigned to 3 dietary treatments in a completely randomized design with 8 replicates per treatment, and 4 birds per replicate. The control group was fed a basal control diet, and the 2 test groups were fed the basal control diet supplemented with 150 and 300 mg/kg of protected complex of biofactors and antioxidants [P(BF+AOX)], respectively. The P(BF+AOx) is a combination of vitamins, L-tryptophan and biofactors such as fermentation extracts (Jefo Nutrition Inc., Saint-Hyacinthe, QC, Canada). Dietary P(BF+AOX) did not affect growth performance and breast meat quality (water holding capacity, cooking loss, shear force, and texture profile analysis), but the addition of 150 mg/kg of P(BF+AOX) decreased the relative weight of liver, heart, and spleen (P < 0.05). The addition of 150 mg/kg of P(BF+AOX) tended to increase (P = 0.051) the cold carcass yield. The addition of 150 and 300 mg/kg of P(BF+AOX) decreased (P = 0.002) the cooler carcass shrink, but the relative weight of fat pad increased (P = 0.032) in chickens fed 300 mg/kg P(BF+AOx) than in those of birds fed the control diet. On the other hand, the addition of 300 mg/kg of P(BF+AOX) decreased (P = 0.041) the serum level of uric acid compared with those of birds fed the basal diet. Broiler chickens fed diets supplemented with 150 mg/kg of diet had higher (P < 0.05) mRNA expressions of jejunal SOD1 and interleukins 6 and 10 (IL-6, IL-10). The findings suggest that P(BF+AOX) could be considered as a functional nutrient in broiler diets up to a concentration of 150 mg/kg because of its favorable effects on maintaining intestinal barrier function as well as carcass traits, while excess levels (300 mg/kg) had exhibited superior effect on the serum level of uric acid compared with those of birds fed the control diet.

Addition of a protected complex of biofactors and antioxidants to breeder hen diets confers transgenerational protection against Salmonella enterica serovar Enteritidis in progeny chicks.

Addition of vitamins and antioxidants has been long associated with increased immunity and are commonly used in the poultry industry; however, less is known regarding their use in broiler breeder hens. The objective of this study was to determine if feeding a complex of protected biofactors and antioxidants composed of vitamins and fermentation extracts to broiler breeder hens conferred resistance against Salmonella enterica serovar Enteritidis (S. Enteritidis) in the progeny chicks. Three-day-old chicks from control- and supplement-fed hens were challenged with S. Enteritidis and necropsied 4- and 11-days postchallenge (dpc) to determine if there were differences in invasion and colonization. Serum and jejunum were evaluated for various cytokine and chemokine production. Fewer (P = 0.002) chicks from supplement-fed hens had detectable S. Enteritidis in the ceca (32.6%) compared to chicks from control-fed hens (64%). By 11 dpc, significantly (P < 0.001) fewer chicks from supplement-fed hens were positive for S. Enteritidis (liver [36%]; ceca [16%]) compared to chicks from the control hens (liver [76%]; ceca [76%]). The recoverable S. Enteritidis in the cecal content was also lower (P = 0.01) at 11 dpc. In additional to the differences in invasion and colonization, cytokine and chemokine production were distinct between the 2 groups of chicks. Chicks from supplement-fed hens had increased production of IL-16, IL-6, MIP-3α, and RANTES in the jejunum while IL-16 and MIP-1ß were higher in the serum of chicks from the control-fed hens. By 11 dpc, production of IFN-γ was decreased in the jejunum of chicks from supplement-fed hens. Collectively, these data demonstrate adding a protected complex of biofactors and antioxidants to the diet of broiler breeder hens offers a measure of transgenerational protection to the progeny against S. Enteritidis infection and reduces colonization that is mediated, in part, by a robust and distinct cytokine and chemokine response locally at the intestine and systemically in the blood.

Morphological Assessment and Biomarkers of Low-Grade, Chronic Intestinal Inflammation in Production Animals.

The complex interaction between the intestinal mucosa, the gut microbiota, and the diet balances the host physiological homeostasis and is fundamental for the maximal genetic potential of production animals. However, factors such as chemical and physical characteristics of the diet and/or environmental stressors can continuously affect this balance, potentially inducing a state of chronic low-grade inflammation in the gut, where inflammatory parameters are present and demanding energy, but not in enough intensity to provoke clinical manifestations. It's vital to expand the understanding of inflammation dynamics and of how they compromise the function activity and microscopic morphology of the intestinal mucosa. These morphometric alterations are associated with the release of structural and functional cellular components into the feces and the blood stream creating measurable biomarkers to track this condition. Moreover, the identification of novel, immunometabolic biomarkers can provide dynamic and predictors of low-grade chronic inflammation, but also provide indicators of successful nutritional or feed additive intervention strategies. The objective of this paper is to review the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

The use of histológical parameters to assess intestinal and liver health on broilers challenged isolatedly and simultaneously with cyclopiazonic acid and aflatoxin / B1 El uso de parámetros histológicos para evaluar la salud intestinal y hepática en pollos de engorde desafiados de forma aislada y simultánea con ácido ciclopiazónico y aflatoxina B1

Abstract Mycotoxins contaminate agricultural commodities, which contaminates animals. These toxins can damage vital organs, such as the liver, as well as the epithelial tissue. Among these mycotoxins are aflatoxin B1 (AFB1) and cyclopiazonic acid (CPA), which can occur simultaneously in food. In broilers, mycotoxicosis has an economic impact due to several factors, such as low feed conversion rate, incidence of other diseases, and interference with reproductive capacity, all of which may lead to a public health problem. The aim of the present study was to histologically assess, through the I See Inside (ISI) method, harmful effects on broiler liver, duodenum, jejunum, and ileum in the presence of AFB1 and CPA isolatedly and simultaneously. Groups challenged with mycotoxins showed significant damage to both gut and liver fragments. All challenged-groups in all fragments impaired the parameters analyzed for intestinal epithelium. In the liver, AFB1 was predominantly harmful when the parameters were analyzed separately, but when analyzing the total ISI score, CPA was also found to be harmful to this organ. The other point analyzed was the great variation between the weights of the birds contaminated by mycotoxin while the negative control group presents a lesser variation.

Resumen Las micotoxinas contaminan los productos agrícolas, que a su vez contaminan a los animales. Estas toxinas pueden dañar órganos vitales, como el hígado y el tejido epitelial. Entre estas micotoxinas se encuentran la aflatoxina B1 (AFB1) y el ácido ciclopiazónico (CPA), que pueden hallarse simultáneamente en los alimentos. En los pollos de engorde, la micotoxicosis tiene un impacto económico debido a varios factores, como la baja tasa de conversión alimenticia, la incidencia de otras enfermedades y la interferencia de la capacidad reproductiva, que pueden llevar a un problema de salud pública. El objetivo de la presente investigación es la de evaluar histológicamente, a través del método "I See Inside" (ISI), los efectos nocivos sobre el hígado, duodeno, yeyuno e íleon de pollos de engorde en presencia de AFB1 y CPA de forma aislada y simultánea. Los grupos desafiados con micotoxinas presentaron un daño significativo tanto en el intestino como en los fragmentos del hígado. Todos los grupos tratados tuvieron alteraciones en los parámetros analizados para el epitelio intestinal. En el hígado, AFB1 fue predominantemente dañino cuando los parámetros se analizaron por separado, pero al examinar la puntuación ISI total, también se encontró que el CPA era perjudicial para este órgano. Otra cuestión que fue investigada fue la gran variación entre los pesos de las aves contaminadas por micotoxinas mientras el grupo de control negativo presentó una variación menor.

Effect of organic acids-essential oils blend and oat fiber combination on broiler chicken growth performance, blood parameters, and intestinal health.

This study evaluated the effect of organic acids-essential oils blend with or without oat hulls (OH) on growth performance, organ weights, blood parameters, gut morphology, microbiota, and short-chain fatty acids (SCFA) in broiler chickens. Day-old broiler chickens were randomly allocated to 4 dietary treatments consisting of 1) a corn-soybean meal-wheat based diet (BAS), 2) BAS + 0.05% bacitracin methylene disalicylate (BMD), 3) BAS + protected organic acids-essential oils at 300 g/1,000 kg of feed (OE), and 4) BAS + protected organic acids-essential oils at 300 g/1,000 kg of feed + 3% OH (OEOH), in 8 replicate groups. Feeding was in starter (d 0 to 14), grower (d 14 to 24), and finisher (d 24 to 36) phases. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), and mortality were determined weekly. On d 36, 8 chickens per treatment were sampled for blood biochemistry, organ weights, cecal SCFA production, and microbiota. Treatments had no effect on FI and FCR at all phases. Both OE and OEOH treatments reduced (P < 0.001) the body weight gain of birds at the starter phase. Birds fed the OEOH treatment had higher (P < 0.001) gizzard weight, while those offered the BMD diet showed a tendency (P = 0.08) to have higher cecal weight. Birds in the OEOH treatment recorded increased ileal villus height and villus height-to-crypt depth ratio, as well as reduced duodenal crypt depth, while birds in the OE treatment had increased jejunal villus height and villus height-to-crypt depth ratio. Both OEOH and OE treatments increased the number of goblet cells produced in the duodenum and jejunum. Treatments had no effect on SCFA concentrations. Birds in the OE treatment recorded the lowest concentration of blood urea (P = 0.05) and cholesterol (P < 0.05). Both OE and OEOH treatments increased (P < 0.05) the relative abundance of potentially beneficial bacteria in the genus Firmicutes_unclassified, Ruminococcus, Turicibacter, and Erysipelotrichaceae_unclassified, while reducing (P < 0.001) the relative abundance of potentially harmful Coprobacillus. Conclusively, both protected organic acids-essential oils blend and its combination with oat fibers show potential as tools to achieve antibiotics reduction in broiler production.

Protected Organic Acid and Essential Oils for Broilers Raised Under Field Conditions: Intestinal Health Biomarkers and Cecal Microbiota.

The objective of the present study was to evaluate the effect of protected organic acids (OA) and essential oils (EO) [P(OA + EO)] on the intestinal health of broiler chickens raised under field conditions. The study was conducted on four commercial farms. Each farm consisted of four barns, two barns under a control diet and two tested barns supplemented with P(OA + EO), totaling 16 barns [8 control and 8 under P(OA + EO)]. The control group was supplemented with antibiotic growth promoters [AGP; Bacitracin Methylene Disalicylate (50 g/ton) during starter, grower and finisher 1, and flavomycin (2 g/ton) during finisher 2]. The tested group was supplemented with 636, 636, 454, and 454 g/ton of P(OA + EO) during starter, grower, finisher 1 and 2, respectively. Eighty birds were necropsied (40/treatment; 20/farm; and 5/barn) to collect blood, jejunal tissue, and cecal contents. The data were submitted to analysis of variance (ANOVA) (P < 0.05) or Kruskal-Wallis' test and the frequency of antimicrobial resistant (AMR) genes was analyzed by Chi-Square test (P < 0.05). It was observed that the supplementation of P(OA + EO) reduced (P < 0.05) the histopathology scores, such as the infiltration of inflammatory cells in the epithelium and lamina propria and tended (P = 0.09) to reduce the serum concentration of calprotectin (CALP). The supplementation of P(OA + EO) reduced the serum concentration of IL-12 (P = 0.0001), IL-16 (P = 0.001), and Pentraxin-3 (P = 0.04). Additionally, P(OA + EO) maintained a cecal microbiota similar to birds receiving AGP. The substitution of AGP by P(OA + EO) reduced (P < 0.05) the frequency of four AMR genes, related to gentamicin (three genes), and aminoglycoside (one gene). Overall, the inclusion of P(OA + EO), and removal of AGP, in the diets of commercially raised broiler chickens beneficially changed the phenotype of the jejunum as shown by the lowered ISI scores which characterizes an improved intestinal health. Furthermore, P(OA + EO) significantly reduced the serum concentration of several inflammatory biomarkers, while maintaining the diversity and composition of the cecal microbiota similar to AGP fed chickens and reducing the prevalence of AMR genes.

Novel Models for Chronic Intestinal Inflammation in Chickens: Intestinal Inflammation Pattern and Biomarkers.

For poultry producers, chronic low-grade intestinal inflammation has a negative impact on productivity by impairing nutrient absorption and allocation of nutrients for growth. Understanding the triggers of chronic intestinal inflammation and developing a non-invasive measurement is crucial to managing gut health in poultry. In this study, we developed two novel models of low-grade chronic intestinal inflammation in broiler chickens: a chemical model using dextran sodium sulfate (DSS) and a dietary model using a high non-starch polysaccharide diet (NSP). Further, we evaluated the potential of several proteins as biomarkers of gut inflammation. For these experiments, the chemical induction of inflammation consisted of two 5-day cycles of oral gavage of either 0.25mg DSS/ml or 0.35mg DSS/ml; whereas the NSP diet (30% rice bran) was fed throughout the experiment. At four times (14, 22, 28 and 36-d post-hatch), necropsies were performed to collect intestinal samples for histology, and feces and serum for biomarkers quantification. Neither DSS nor NSP treatments affected feed intake or livability. NSP-fed birds exhibited intestinal inflammation through 14-d, which stabilized by 36-d. On the other hand, the cyclic DSS-treatment produced inflammation throughout the entire experimental period. Histological examination of the intestine revealed that the inflammation induced by both models exhibited similar spatial and temporal patterns with the duodenum and jejunum affected early (at 14-d) whereas the ileum was compromised by 28-d. Calprotectin (CALP) was the only serum protein found to be increased due to inflammation. However, fecal CALP and Lipocalin-2 (LCN-2) concentrations were significantly greater in the induced inflammation groups at 28-d. This experiment demonstrated for the first time, two in vivo models of chronic gut inflammation in chickens, a DSS and a nutritional NSP protocols. Based on these models we observed that intestinal inflammation begins in the upper segments of small intestine and moved to the lower region over time. In the searching for a fecal biomarker for intestinal inflammation, LCN-2 showed promising results. More importantly, calprotectin has a great potential as a novel biomarker for poultry measured both in serum and feces.

Field evaluation of feeding spray-dried plasma in the starter period on final performance and overall health of broilers.

The effect of feeding spray-dried plasma (SDP) during the starter period was evaluated with a commercial broiler integrator on performance and overall health of broilers. The I See Inside (ISI) methodology assessing gut health in broilers was used as a tool to evaluate the impact of dietary interventions under commercial conditions. One hundred farms with approximately 1.1 million broilers were used at a Brazilian broiler integrator. Two groups of farms were fed either a control or an SDP diet containing 1% SDP, from 0 to 10 d of age. Diets were formulated to have similar nutritional density, containing zinc bacitracin and CuSO4 from 0 to 28 d. After 10 d, both groups were fed common commercial diets. Performance data were analyzed together or by type of ventilation system: positive pressure or negative pressure. Birds were sent to market as they reached 3.05 kg; therefore, age at slaughter (AS) was evaluated as a dependent variable along with other performance measures. From the 100 farms in the trial, 35 (16 control and 19 SDP farms) were selected for the assessment of broilers health, biosecurity, and local management. For that, 6 broilers per farm at 14 ± 2 d of age were necropsied and ileum sampled for the ISI methodology evaluation. Biosecurity and management were also evaluated to obtain the influence of those parameters on animal health. SDP-fed birds demonstrated improved feed conversion ratio, reduced mortality, and 1 d less for AS (P < 0.05) vs. control group (P < 0.05) regardless of the type of ventilation. During necropsy, birds fed SDP showed lower coccidiosis and locomotor system lesions as the overall ISI score compared to controls. Histologic intestinal alterations were also lower in SDP-fed broilers (P < 0.05). In conclusion, feeding 1% SDP in the starter period to broilers resulted in improved performance and health under both good and bad management and biosecurity standards independent of the type of ventilation. Overall, there was good agreement between the ISI method and performance improvements observed.

Association between non-typhoidal Salmonella isolated from commercial poultry sheds and associated factors in Paraná, Brazil: Cross-sectional retrospective study

The epidemiology of salmonellosis in poultry is complex, which makes it difficult to identify the origin and spread of this disease in poultry farms. The aims of this study were to characterize the spatial distribution of Salmonella enterica in epidemiological units in Paraná, Brazil; and to investigate correlations between this microorganism and associated factors. Among the epidemiological units, 78 of 243 (32.10%) were positive. Spatially, the northwestern and western regions had higher concentrations of positive cases than the other regions. In bivariate analyses, the presence of other animal species in the epidemiological unit (prevalence ratio, PR = 0.64; 95% confidence interval, CI = 0.43­0.95; p = 0.022) and proximity to establishments at risk (PR = 0.51; 95% CI = 0.32­0.81; p = 0.001) did not influence positivity, but the average population per poultry shed (between 30,501 and 32,500; PR = 2.57; 95% CI = 1.72­3.83; p = 0.001) was associated with Salmonella positivity. Multiple logistic regression demonstrated that the average population per poultry shed, presence of surrounding risk-posing establishments and presence of surrounding poultry sheds produced a significant multiple model for S. enterica. The results indicated that the presence of S. enterica may be related to higher density broiler in poultry sheds, presence of surrounding poultry sheds, proximity between positive and negative epidemiological units and altitude of the municipality. The information obtained showed that some factors were related to positivity for this microorganism and emphasizes the importance of serotyping to obtain other epidemiological data.

Comparing performance and resistance of two broilers breeds challenged by Eimeria acervulina.

The proposal on the ban of anticoccidials drugs from poultry feed highlights the importance of broiler breeders resistance to Eimeria as a criteria for animal genetic selection. The aim of this study was to compare the resistance between two commercial broiler breeds to Eimeria acervulina. Eight hundred male chicks from two commercial breeds (400 animals each) were housed from 1-42 days of age and randomly divided into 4 treatments with 8 replicates of 25 birds each. Following a factorial design, the treatments were AU, BU (breed A and B, unchallenged), AC and BC (breed A and B, challenged at 14 days of age by gavage with 1 × 106 oocysts of a field strain of E. acervulina). From 1-42 days, feed intake, body weight gain (BWG), feed conversion ratio (FCR), feed efficiency and mean weight (MW) were weekly measured. For the clinical evaluation, feces were sampled from 18 to 24 days for the counting of excreted oocysts and twenty birds per treatment were euthanized at 20 days of age for the scoring of macroscopic lesions in the gut. The breeds did not show statistical differences in performance after the Eimeria challenge in all phases. Breed A presented a higher increase in FCR from 21 to 45 days in comparison to the breed B, which presented a deeper reduction in FI, BWG and MW at all periods post-infection when compared to the breed A. Despite of the challenge, breed A presented better performance indexes (P < 0.05) up to the 28 days of age in comparison to the breed B, however, no significant difference in performance was detected between the breeds at the final age of 42 days. Regardless of the breed, the challenged birds presented significant worsens in all performance parameters from 14 to 42 days of age. The breed B presented a higher (P < 0.05) fecal count of oocysts from 19 to 21 days and higher (P < 0.05) score of macroscopic lesions in the gut at 21 days in comparison to the breed A. The clinical evaluation pointed out a lower resistance of the breed B to the E. acervulina challenge, which could result in significant impacts on the performance in field production conditions.

Effects of a microencapsulated formula of organic acids and essential oils on nutrient absorption, immunity, gut barrier function, and abundance of enterotoxigenic Escherichia coli F4 in weaned piglets challenged with E. coli F4.

The objective was to study the effects of microencapsulated organic acids (OA) and essential oils (EO) on growth performance, immune system, gut barrier function, nutrient digestion and absorption, and abundance of enterotoxigenic Escherichia coli F4 (ETEC F4) in the weaned piglets challenged with ETEC F4. Twenty-four ETEC F4 susceptible weaned piglets were randomly distributed to 4 treatments including (1) sham-challenged control (SSC; piglets fed a control diet and challenged with phosphate-buffered saline (PBS)); (2) challenged control (CC; piglets fed a control diet and challenged with ETEC F4); (3) antibiotic growth promoters (AGP; CC + 55 mg·kg-1 of Aureomycin); and (4) microencapsulated OA and EO [P(OA+EO); (CC + 2 g·kg-1 of microencapsulated OA and EO]. The ETEC F4 infection significantly induced diarrhea at 8, 28, 34, and 40 hr postinoculation (hpi) (P < 0.05) in the CC piglets. At 28 d postinoculation (dpi), piglets fed P(OA+EO) had a lower (P < 0.05) diarrhea score compared with those fed CC, but the P(OA+EO) piglets had a lower (P < 0.05) diarrhea score compared with those fed the AGP diets at 40 dpi. The ETEC F4 infection tended to increase in vivo gut permeability measured by the oral gavaging fluorescein isothiocyanate-dextran 70 kDa (FITC-D70) assay in the CC piglets compared with the SCC piglets (P = 0.09). The AGP piglets had higher FITC-D70 flux than P(OA+EO) piglets (P < 0.05). The ETEC F4 infection decreased mid-jejunal VH in the CC piglets compared with the SCC piglets (P < 0.05). The P(OA+EO) piglets had higher (P < 0.05) VH in the mid-jejunum than the CC piglets. The relative mRNA abundance of Na+-glucose cotransporter and B0AT1 was reduced (P < 0.05) by ETEC F4 inoculation when compared with the SCC piglets. The AGP piglets had a greater relative mRNA abundance of B0AT1 than the CC piglets (P < 0.05). The ETEC F4 inoculation increased the protein abundance of OCLN (P < 0.05), and the AGP piglets had the lowest relative protein abundance of OCLN among the challenged groups (P < 0.05). The supplementation of microencapsulated OA and EO enhanced intestinal morphology and showed anti-diarrhea effects in weaned piglets challenged with ETEC F4. Even if more future studies can be required for further validation, this study brings evidence that microencapsulated OA and EO combination can be useful within the tools to be implemented in strategies for alternatives to antibiotics in swine production.

Microbiome and pathogen interaction with the immune system.

The intestinal tract harbors a diverse community of microbes that have co-evolved with the host immune system. Although many of these microbes execute functions that are critical for host physiology, the host immune system must control the microbial community so that the dynamics of this interdependent relationship is maintained. To facilitate host homeostasis, the immune system ensures that the microbial load is tolerated, but anatomically contained, while remaining reactive to microbial invasion. Although the microbiota is required for intestinal immune development, immune responses regulate the structure and composition of the intestinal microbiota by evolving unique immune adaptations that manage this high-bacterial load. The immune mechanisms work together to ensure that commensal bacteria rarely breach the intestinal barrier and that any that do invade should be killed rapidly to prevent penetration to systemic sites. The communication between microbiota and the immune system is mediated by the interaction of bacterial components with pattern recognition receptors expressed by intestinal epithelium and various antigen-presenting cells resulting in activation of both innate and adaptive immune responses. Interaction between the microbial community and host plays a crucial role in the mucosal homeostasis and health status of the host. In addition to providing a home to numerous microbial inhabitants, the intestinal tract is an active immunological organ, with more resident immune cells than anywhere else in the body, organized in lymphoid structures called Peyer's patches and isolated lymphoid follicles such as the cecal tonsils. Macrophages, dendritic cells, various subsets of T cells, B cells and the secretory immunoglobulin A (IgA) they produce, all contribute to the generation of a proper immune response to invading pathogens while keeping the resident microbial community in check without generating an overt inflammatory response to it. IgA-producing plasma cells, intraepithelial lymphocytes, and γδT cell receptor-expressing T cells are lymphocytes that are uniquely present in the mucosa. In addition, of the γδT cells in the intestinal lamina propria, there are significant numbers of IL-17-producing T cells and regulatory T cells. The accumulation and function of these mucosal leukocytes are regulated by the presence of intestinal microbiota, which regulate these immune cells and enhance the mucosal barrier function allowing the host to mount robust immune responses against invading pathogens, and simultaneously maintains immune homeostasis.

Protected Blend of Organic Acids and Essential Oils Improves Growth Performance, Nutrient Digestibility, and Intestinal Health of Broiler Chickens Undergoing an Intestinal Challenge.

The growing restriction of antibiotic growth promoters (AGP) use in farming animals has raised a concern regarding the viability of the animal production system. In this new context, feed additives with proven positive impact on intestinal health may be used as strategy to avoid losses on performance. The aim of this study was to evaluate the effects of a protected blend of organic acids and essential oils [P(OA+EO)] on growth performance, nutrient digestibility, and intestinal health of broiler chickens. A total of 1,080 Cobb × Cobb 500 male broilers were randomly distributed in four treatments with 10 replicates (27 birds/each). Treatments were as follow: non-challenged control; challenged control; AGP (enramycin at 10 g/t); and P(OA+EO) at 300 g/t. All birds on challenged groups were challenged with Eimeria spp. at 1 day and with Clostridium perfringens at 11, 12, and 13 days. Body weight gain (BWG), feed intake and feed conversion ratio (FCR) were evaluated until 42 days. At 17 days, one bird per pen was orally gavaged with fluorescein isothiocyanate-dextran (FITC-d) and blood samples were collected for FITC-d detection to assess intestinal permeability. At 21 days, apparent ileal nutrient and energy (IDE) digestibility, intestinal macroscopic and histologic alterations (ISI) and, expression of mucin2 (MUC2), claudin1 (CLDN1), and occludin (OCLN) genes in the jejunum were evaluated. From 1 to 42 days, birds from the non-challenged and P(OA+EO) groups had greater (P < 0.001) BWG compared to challenged control and AGP groups. The challenged control group presented the worst FCR (P < 0.001). IDE was 106 kcal/kg greater when broilers were fed P(OA+EO) compared to the challenged control group. Broilers supplemented with P(OA+EO) had improved intestinal integrity with lower blood FITC-d concentration and ISI scores, and greater expression of MUC2, CLDN1, and OCLN genes compared to the challenged control group (P < 0.05). In conclusion, the P(OA+EO) and the AGP led to increased growth performance, nutrient digestibility and intestinal health of challenged broilers. A marked difference occurred in favor of the P(OA+EO), suggesting that this blend may be used to improve intestinal health and broiler growth performance in AGP free programs.

Basal and Infectious Enteritis in Broilers Under the I See Inside Methodology: A Chronological Evaluation.

Recently, the inflammation of the intestinal mucosa has been related to many diseases in humans and animals. The concept of Microscopic Enteritis (ME) used in human pathology through the Marsh classification system has no counter-part in veterinary medicine. In poultry science, the I See Inside (ISI) methodology, unlike the current linear measures of villi and crypts, generates possibilities to describe and understand the avian ME. Through specific parameters, graded from 0 to 3, the model links proliferative and/or inflammatory reactions in the intestinal layers to some loss in performance. Herein, two trials were conducted in order to describe the development of ME through the ISI methodology in chickens challenged or not with Eimeria spp. and Clostridium perfringens. In each trial, a total of 64 birds were divided in 2 treatments with 4 replicates containing 8 birds each: non-challenged (NCH) and challenged (CH) through gavage with an Eimeria spp. vaccine at 1 day of age and 108 CFU/mL of Clostridium perfringens administered at 10, 11, and 12 days of age. At 7, 14, 21, and 28 days of age birds were euthanized and samples of ileum and liver were collected for ISI evaluation, cytokines and presence of macrophages, CD4+ and CD8+ cell. The results allowed the description of the avian Microscopic Enteritis and of its two basic components: a basal enteritis (BE) in NCH broilers, over which the infectious enteritis is developed in CH birds. In addition, the chronology of ME translated by the ISI methodology parameters were associated to losses in zootechnical performance.

Applying I see inside histological methodology to evaluate gut health in broilers challenged with Eimeria.

The present study evaluated the effects of coccidiosis on histological parameters and performance of broilers submitted to a mild challenge with Eimeria sp. A total of 132 broilers were randomly divided into two groups with 6 replicates of 11 birds each: negative control (NC) - birds uninfected and challenge (CH) - birds infected by gavage at day-one with 10x the manufacturer recommended dose of Bio-Coccivet R® live vaccine by Biovet, with strains of E. acervulina, E. brunetti, E. maxima, E. necatrix, E. praecox, E. tenella and E. mitis. From 1 to 28 d of age, weekly the zootechnical performance was evaluated and samples of the liver, duodenum, jejunum and ileum were collected and submitted to histological analysis by the I See Inside methodology (ISI). The ISI methodology is a metric evaluation of histological alterations in the intestine and liver. Which translates macroscopic and microscopic alterations into numbers and allows their correlation with the animal zootechnical performance. Pearson's correlation was used to demonstrates how the damages to the gut, evaluated by ISI method, could affect negatively the performance of broilers. The presence of oocysts in histological analysis of the jejunum and ileum at 7d indicate a negative effect on performance over the next 2 weeks (14d and 21d). When the ISI total score was measured in the ileum at 14d, we observed a strong negative effect on zootechnical performance from that period on 14d, 21d and 28d. The obtained data demonstrates that the higher the ISI scores, the worse are the zootechnical performance results of broilers challenged with Eimeria sp. and the I See Inside scores could be applied to evaluate coccidiosis effect on performance in future.

Applying I see inside histological methodology to evaluate gut health in broilers challenged with Eimeria.

The present study evaluated the effects of coccidiosis on histological parameters and performance of broilers submitted to a mild challenge with Eimeria sp. A total of 132 broilers were randomly divided into two groups with 6 replicates of 11 birds each: negative control (NC) - birds uninfected and challenge (CH) - birds infected by gavage at day-one with 10x the manufacturer recommended dose of Bio-Coccivet R® live vaccine by Biovet, with strains of E. acervulina, E. brunetti, E. maxima, E. necatrix, E. praecox, E. tenella and E. mitis. From 1 to 28 d of age, weekly the zootechnical performance was evaluated and samples of the liver, duodenum, jejunum and ileum were collected and submitted to histological analysis by the I See Inside methodology (ISI). The ISI methodology is a metric evaluation of histological alterations in the intestine and liver. Which translates macroscopic and microscopic alterations into numbers and allows their correlation with the animal zootechnical performance. Pearson's correlation was used to demonstrates how the damages to the gut, evaluated by ISI method, could affect negatively the performance of broilers. The presence of oocysts in histological analysis of the jejunum and ileum at 7d indicate a negative effect on performance over the next 2 weeks (14d and 21d). When the ISI total score was measured in the ileum at 14d, we observed a strong negative effect on zootechnical performance from that period on 14d, 21d and 28d. The obtained data demonstrates that the higher the ISI scores, the worse are the zootechnical performance results of broilers challenged with Eimeria sp. and the I See Inside scores could be applied to evaluate coccidiosis effect on performance in future.

Schirmer's I, modified Schirmer's I, phenol red thread, and paper point tests: a comparative study for tear production measurement techniques in broiler chicks (Gallus gallus domesticus).

Problems with indoor husbandry and immunological challenges are some of the stressors that broilers may face which can affect production. Infectious diseases can compound the effects of excessive concentrations of ammonia causing respiratory and ocular inflammation and increased lacrimal production in broiler chickens. The objectives of this investigation were to establish normal values of tear production in chicks and compare the practicality of the different methods. Palpebral fissure length (PFL) and tear production were evaluated in Cobb 500 chicks at 5 d old and then at 5 d of age by the following methods: modified Schirmer's test I (mSTT1), phenol red cotton thread tear test (PRCTTT), and standardized endodontic absorbent paper point test (EAPPTT). Ten chicks at the age of 5 and 42 d were evaluated for each method. In addition, at 42 d, when the palpebral fissure permitted, a regular-sized Schirmer tear test I (STT1) was performed in another group of 10 chickens. Overall, PFL and the secretion of the aqueous phase of the tear film increased with age. Mean mSTT1 results were 5.00 ± 1.83 mm and 10.45 ± 2.58 mm for 5- and 42-d-old chicks, respectively. Mean PRCTTT results were 12.37 ± 1.80 mm and 25.58 ± 4.8 mm for 5- and 42-d-old chicks, respectively. Mean EAPPTT results were 7.13 ± 0.72 mm and 12.03 ± 0.92 mm for 5- and 42-d-old chicks, respectively. Mean STT1 for 42-d-old chicks was 11.40 ± 2.60 mm. Results obtained with endodontic paper points showed the lowest coefficient of variation and investigators found the test easier to perform. These values reported for broilers at different ages may be applied in poultry ophthalmology to help the diagnosis of lacrimal production disorders and to detect early disease symptoms that could cause economic losses in poultry production.