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The microbiome has entered the vernacular of the consumer as well as broiler production and is, therefore, becoming increasingly important to poultry producers to understand. The microbiome is, by definition, compositional and relates to how the microbiological organisms within the gut inhabit that ecological niche. The gut is diverse, flexible, and data acquired requires a greater understanding of the host-microbiome axes, as well as advanced bioinformatics and ecology. There are numerous microbial populations that define the gut microbiome; however, there are even more effects that can influence its composition. As management practices vary between producers, documenting these influences is an essential component of beginning to understand the microbiome. This review targets broiler production and concatenates the currently understood compositional ecology of the broiler gastrointestinal tract microbiome as well as its influences.

Heat stress (HS) is a financial and physiological burden on the poultry industry and the mitigation of the adverse effects of HS is vital to poultry production sustainability. The purpose of this study was, therefore, to determine the effects of an amino acid-chelated trace mineral supplement on growth performance, stress and inflammatory markers, and meat quality in heat-stressed broilers. One day-old Cobb 500 male broilers (n = 480) were allocated into 12 environmental chambers (24 floor pens) and divided into two groups: one group supplemented with amino acid-chelated trace mineral in drinking water and one control group. On day 28, birds were subjected to chronic heat stress (HS, 2 wk, 35 °C and 20% to 30% RH) or maintained at thermoneutral condition (TN, 24 °C) in a 2 × 2 factorial design. Feed intake (FI), water consumption, and body weight were recorded. At day 42, serum fluorescein isothiocyanate dextran (FITC-D) levels, blood gas, electrolyte, and stress markers were measured. Jejunum samples were collected to measure gene expression of stress, inflammation, and tight junction proteins. The rest of the birds were processed to evaluate carcass traits. HS resulted in an increase in core body temperature, which increased water intake and decreased FI, body weight, and feed efficiency (P < 0.05). HS reduced carcass yield and the weight of all parts (P < 0.05). HS significantly increased levels of circulating corticosterone (CORT), heat shock protein 70 (HSP70), interleukin 18 (IL-18), tumor necrosis factor alpha, C-reactive protein, and nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing 3 expression. HS significantly increased serum FITC-D levels and the expression of HSP70 and IL-18 in the jejunum. Although it did not affect the growth performance, amino acid-chelated trace mineral supplementation reversed the effect of HS by reducing CORT and FITC-D levels and the expression of stress and proinflammatory cytokines in the circulation and the jejunum. However, it upregulated these parameters in birds maintained under TN conditions. Together, these data indicate that the amino acid-chelated trace mineral might alleviate stress and inflammation and improve gut integrity in heat-stressed but not thermoneutral broilers.

SUMMARY Two experiments were conducted in a commercial broiler hatchery to evaluate the use of a spray probiotic formulation as an alternative method to control the bacterial bloom within a broiler hatch cabinet vs. formaldehyde fumigation. In Exp 1, 2 independent trials were conducted to compare hatchery sanitation between the current formaldehyde drip method vs. spray application of the probiotic. Hatchery sanitation was evaluated using the open-plate method at approximately 20% pip; 30% hatch; and 85% hatch for enumeration of total recovered non-selective aerobic bacteria (TAB); presumptive lactic acid bacteria (LAB); and total recovered Gram-negative bacteria (TGB). In Exp 2, 3 independent trials were conducted to evaluate the gastrointestinal (GIT) microbiota of neonatal chicks from hatch cabinets treated as in Exp 1. In Exp 1, in both trials, the application of the probiotic increased the number TAB and LAB present in the hatching environment (P

Aging, poor oxygenation, or improper storage temperature can lead to variable Eimeria oocyst viability, which is not readily assessed microscopically. Under fluorescent microscopy, some aged Eimeria maxima (EM) oocysts were strongly autofluorescent (AF) within the oocystoplasm and sporocysts, whereas others were distinctly non-fluorescent, leading to the hypothesis that non-viable oocysts may be detectible using this simple approach. Using accelerated aging conditions at 45°C, two experiments were conducted to evaluate variable percentages of autofluorescent EM oocysts on body weight gain (BWG), lesion scores (LS), and total oocyst shedding (OS) per bird. Through oral gavage, EM oocysts were administered on d10, whereas LS and BWG were determined d5 post-inoculation. Experiment 1 groups consisted of non-challenged controls (n = 15), or 25,000 EM exhibiting 12.8% (n = 14), 61.1% (n = 10), or 93.3% (n = 10) autofluorescence. BWG in 12.8% AF group was lower (P = 0.054) than non-challenged control. LS were higher (P0.05) in 61.1% and 12.8% AF groups as compared to non-challenged control and 93.3% AF groups. Experiment 2 groups consisted of non-challenged controls (LS n = 20/BWG n = 40), or 22,500 EM exhibiting 7% AF (LS n = 20/BWG n = 40), 80.6% AF (LS n = 19/BWG n = 39), or 99% AF (LS n = 19/BWG n = 39). BWG in 7% AF group was lower (P0.05) than non-challenged control and 99% AF groups. LS were higher (P0.05) in 80.6% and 7% AF groups as compared to non-challenged control and 99% AF groups. OS from d5-8 post-inoculation was determined for each of five replicates per group (n = 20/group; n = 4/replicate), with higher (P0.05) OS in 80.6% and 7% AF groups than in non-challenged control or 99% AF groups. Taken together, data indicate lower LS, higher BWG, and reduced OS with higher %AF oocysts, consistent with the hypothesis of lowered viable challenge with this EM isolate.

Two experiments were conducted to evaluate the effects of humic acids (HA) on recovery of Salmonella Enteritidis, in an in vitro digestive system and on intestinal colonization in neonate broiler chickens. In experiment 1, two runs using an in vitro digestion model with two sources of HA (commercial or natural extraction) at 0.1 or 0.2%, and inoculated with 107 CFU/tube of S. Enteritidis, were carried out. In experiment 2, one-day-old male broiler chickens were randomly allocated to one of two groups (n=25) with or without 0.2% of isolated HA from worm compost, and challenged with 106 CFU of S. Enteritidis per chicken at 10-d old. All chicks were euthanized 24-h post challenge, and were subjected to serum fluorescein isothiocyanate dextran (FITC-d) determination. A section of ileum was removed to obtain total concentration of IgA. Ceca-cecal tonsils were removed to evaluate Salmonella recovery, total lactic acid bacteria (LAB) and total Gram negative bacteria. In experiment 1, neither concentration of commercial nor natural HA were able to reduce the recovery of S. Enteritidis in any of the simulated compartments (P>0.05). Only the crop compartment showed significant differences in pH in both trials between control and treated groups. In experiment 2, no significant differences were observed in serum concentration of FITC-d, intestinal IgA, S. Enteritidis recovery, LAB or total Gram negative bacteria in the ceca between control and treated chickens. In conclusion, no effects of HA on recovery of Salmonella Enteritidis, in an in vitro digestive system and on intestinal colonization of Salmonella, bacterial counts in ceca, intestinal IgA and serum FITC-d in neonate broiler chickens were observed. Further studies to evaluate the effect of HA under feed restriction model as an inducer of intestinal inflammation are currently being conducted.

The present study evaluated the microbiological properties of three probiotic candidate strains of lactic acid bacteria (LAB) (128; 131; CE11_2), their effect on intestinal epithelial permeability, and their ability to reduce intestinal colonization of Salmonella Typhimurium (ST) individually or as a batch culture in neonatal turkey poults. Isolates were characterized morphologically and identified using 16S rRNA sequence analyses. Each isolate was evaluated for tolerance and resistance to acidic pH, high osmotic NaCl concentrations, and bile salts in broth medium. In vitro assessment of antimicrobial activity against different enteropathogenic bacteria was determined using an overlay technique. In vitro intestinal permeability was evaluated using a stressed Caco-2 cell culture assay treated with/without the probiotic candidates. The in vivo effect of the selected LAB strains on ST cecal colonization was determined in two independent trials with neonatal turkey poults. The results obtained in this study demonstrate the tolerance of LAB candidates to pH 3, a NaCl concentration of 6.5%, and high bile salts (0.6%). All strains evaluated exhibited in vitro antibacterial activity against Salmonella Enteritidis, ST, and Campylobacter jejuni. Candidates 128 and 131 exhibited a coccus morphology and were identified as Enterococcus faecium, and bacterial strain CE11_2 exhibited clusters of cocci-shaped cells and was identified as Pediococcus parvulus. All three candidate probiotics significantly (P

Objective To standardize an ELISA protocol to quantify total immunoglobulin A (IgA) from different biological samples. Methods Two independent experiments were conducted. In Experiment 1, total IgA levels were quantified from the lachrymal fluid, tracheal swab, and cloacal swab at various time points from Days 30 to 89 in white Leghorn chickens. Experiment 2 was conducted to evaluate the effect of 50 or 500 ppb of aflatoxin B1 (AFB1) on total IgA quantified in samples from the lachrymal fluid, tracheal swab, gut content and cloacal swab in broiler chickens at 21 days of age. Results Lachrymal fluid contained the highest level of IgA; however, the sampling procedure was time consuming and stressful to the bird, and the sample volume depends largely on the size of the chicken. Cloacal swabs also contained a high concentration of IgA; this sampling procedure was faster than lachrymal fluid sampling and was not affected by the age of the bird. Tracheal sampling was more difficult than cloacal sampling; the age of the bird limited the sampling, and the IgA concentration was the lowest detected at all sampling ages. 500 ppb of AFB1 significantly reduced total IgA concentration in the gut content compared with control or 50 ppb of AFB1 treated groups. Interestingly, a significant reduction in total IgA was also observed in those chickens that received 50 ppb of AFB1 in gut rinse when compared with cloacal swabs. Conclusions The results of this study suggest that cloacal swab is an easy and reliable way to evaluate mucosal IgA concentration in both Leghorn and broiler chickens.

Dexamethasone (Dex), a synthetic glucocorticoid (GC), in feed has been shown to increase gut permeability via stress-mediated mechanisms, but the exact mode of action on gut barrier function is not fully understood. Stress has been reported to alter the profile and virulence of intestinal flora predisposing for opportunistic disease. This study aimed to evaluate the relationship between dietary Dex and recoverable intestinal microbial profile in broilers to better understand mode of action and refine future uses of the model. Three experiments were conducted that administered Dex-treated feed for one week in conjunction with the antibiotics BMD (bacitracin methylene disalicylate) or Baytril&reg, (enrofloxacin) to evaluate if enteric microbial mechanisms were important in Dex-induced permeability. Serum fluorescein isothiocyanate-dextran (FITC-d) and bacterial translocation (BT) have been reported to increase after Dex treatment and were used to assess gut epithelial leakage. Shifts in bacterial profiles were also measured on selective agar. Combining Dex with BMD or Baytril resulted in increased (P &lt, 0.05) serum FITC-d versus Dex-only. Additionally, Baytril did not reduce aerobic BT and bacterial profiles remained similar after Dex. These results suggest a minimal role of intestinal microbes in Dex-induced changes to intestinal barrier function.

In humans, alterations in bone metabolism have been associated with myopathies. We postulate the hypothesis that perhaps similar pathologies can also be associated in modern chickens. Hence, this study aimed to assess the fat infiltration in bone marrow and its repercussion on broiler chicken affected by Wooden Breast (WB) myopathy. Ten Cobb 500 live birds with extreme rigidity of the Pectoralis major (PM) muscle were selected as WB affected chickens by physical examination of the muscle at 49 days of age, whereas ten chickens healthy with no physical signs of hardness in the breast muscle were considered to be unaffected. Macroscopic lesions in affected chickens included areas of firm and inflamed muscle with pale appearance, hemorrhaging, and viscous exudate on the surface. Bone marrow and sections of the PM muscle were collected and analyzed for light microscopy. Additionally, transmission electron microscopy was conducted in affected or unaffected muscle. Chickens affected with WB showed significant reductions (P < 0.05) in femur diameter, calcium, and phosphorous percentage but increased breast weight, compression force and filet thickness when compared with non-affected chickens. Interestingly, bone marrow from WB chicken had subjectively, more abundant infiltration of adipose tissue, when compared with non-affected chickens. Histology of the Pectoralis major of birds with WB showed abundant infiltration of adipose tissue, muscle fibers degeneration with necrosis and infiltration of heterophils and mononuclear cells, connective tissue proliferation, and vasculitis. Ultrastructural changes of WB muscle revealed lack definition of bands in muscle tissue, or any normal ultrastructural anatomy such as myofibrils. The endomysium components were necrotic, and in some areas, the endomysium was notable only as a string of necrotic tissue between degraded myofibrils. The fascia appeared hypertrophied, with large areas of necrosis and myofiber without structural identity with degraded mitochondria adjacent to the disrupted muscle tissue. As far as we know, this is the first study that describes a subjective increase in adipose tissue in the bone marrow of chickens affected with WB when compared with non-affected chickens, and reduced bone mineralization.

Intestinal health is essential for feed efficiency and growth in animal agriculture and is dependent on barrier function, inflammation and dysbiosis. Our laboratory has published a nutritional model to induce gut inflammation using rye as a source of energy in poultry. More recently, we have used this model as an assessment of a nutritional rehabilitation model for better understanding of childhood undernutrition. The objective of this brief research report was to use a well-establish malabsorption model in broiler chickens using corn and rye as an energy source to identify several intestinal health biomarkers in the serum. To screen for inflammatory biomarkers, seven commercially available tests were used including Griess, superoxide dismutase, thiobarbituric acid reactive substances, Total antioxidant capacity, extracellular-signal-regulated kinase, Citrulline, and Interferon-ɤ; total IgA from cloacal swab was also measured. In the present study, chickens fed rye had a significant (P < 0.05) reduction in body weight and body weight gain at 10 day when compared with chickens that received the corn diet. In the second phase of the experiment, chickens that remain with the corn diet had significant differences in body weight and body weight gain. No significant differences were observed for any of the four antioxidant biomarkers evaluated in the sera (P > 0.05). However, significant differences were observed in serum citrulline and IFN-ɤ, as well as in cloacal IgA, in broiler chickens fed with rye, suggesting their potential use as biomarkers to study intestinal inflammation.

The objective of this study was to evaluate the of intestinal permeability and liver bacterial translocation (BT) across a modern commercial broiler, a commercial broiler of 1995 genetics, and an unselected Jungle Fowl line. Modern 2015 (MB2015) broiler chicken, random bred line initiated from 1995 (RB1995), and the Giant Jungle fowl (JF). Chickens were randomly allocated to four different dietary treatments. Dietary treatments were (1) a control corn-based diet throughout the trial [corn-corn (C-C)]; (2) an early phase malnutrition diet where chicks received a rye-based diet for 10 days, and then switched to the control diet [rye-corn (R-C)]; (3) a malnutrition rye-diet that was fed throughout the trial [rye-rye (R-R)]; and (4) a late phase malnutrition diet where chicks received the control diet for 10 days, and then switched to the rye diet for the last phase [corn-rye (C-R)]. Paracellular permeability was evaluated using fluorescein isothiocyanate dextran (FITC-D). Liver BT was also evaluated. MB2015 and RB1995 consuming the rye-based diet showed increase serum levels of FITC-D when compared to the corn-fed chickens (P < 0.05). Overall, MB2015 appeared to have higher enteric permeability than the JF. To our knowledge, this would be the first paper to evaluate the effect of compensatory growth on intestinal permeability and liver BT. Further studies to evaluate microbiome and inflammatory markers in these chicken models are currently being evaluated.

Necrotic enteritis (NE) is a recognized multifactorial disease that cost annually to the poultry industry around $2 billion. However, diverse aspects related to its presentation are not completely understood, requiring further studies using known induction experimental models. Therefore, the purpose of this study was to measure the changes occurring in performance, intestinal integrity and ileal microbiome using a previously established NE-challenge model. Chickens were assigned to a negative control group (NC) or a positive control group (PC). In the PC, broilers were orally gavaged with Salmonella Typhimurium (ST) (1 × 107 cfu/chick) at day 1, Eimeria maxima (EM) (2.5 × 104 oocyst/chick) at day 18 and Clostridium perfringens (CP) (1 × 108 cfu/chick/day) at 23–24 days of age. Weekly, body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were evaluated. Morbidity and mortality were determined throughout the study, and NE lesion scores were recorded at day 25. Additionally, blood and liver samples were collected to measure gut permeability as determined by levels of serum fluorescein isothiocyanate-dextran (FITC-d) and bacterial translocation (BT). Ileal contents were processed for 16S rRNA gene-based microbiome analysis. Performance parameters and intestinal permeability measurements were negatively impacted in the PC resulting in elevated serum FITC-d and BT with a −6.4% difference in BWG. The NE lesion score in PC (1.97 vs. 0.00) was significantly higher in comparison to NC, although there was no difference in mortality. The microbiome analysis showed a dramatic shift of ileal microbiomes in PC groups as compared to NC (ANOSIM: R = 0.76, P = 0.001). The shift was characterized by reduced abundance of the phylum Actinobacteria (P < 0.01), and increased abundance of the genera Butyrivibrio, Lactobacillus, Prevotella and Ruminococcus in PC compared to NC (P < 0.05). Expectedly, Clostridium was found higher in PC (2.98 ± 0.71%) as compared to NC (1.84 ± 0.36%), yet the difference was not significant. In conclusion, results of the present study showed the different intestinal epithelial and microbiological alterations occurring in an established NE-challenge model that considers paratyphoid Salmonella infections in young chicks as an important predisposing factor for presentation of NE.

The objectives of the present study were to evaluate the antimicrobial effect of boric acid (BA) on Salmonella enteritidis colonization, intestinal permeability, total intestinal IgA levels, and cecal microbiota composition in broiler chickens. For this purpose, sixty day-old-chicks were randomly allocated to one of two groups: 1) non-treated control group and 2) 0.1% (w/w) BA in feed. All chicks were challenged with 104 cfu of S. Enteritidis per bird at 1-d old. On day 3 and 10 post-challenge, samples of crop and ceca-cecal tonsils (CCT) were aseptically collected to evaluate overall aerobic and lactic acid bacteria, as well as S. Enteritidis recovery. Blood and intestinal samples were also collected to evaluate intestinal permeability and total intestinal IgA production, respectively. On day 10 post-challenge, the concentration of S. Enteritidis in crop and CCT significantly decreased (P

In the present study, in vitro assays were conducted to evaluate the solubility of curcumin (CUR) alone or with polyvinylpyrrolidone (PVP) at different pH, as well as its permeability in Caco-2 cells. Results confirmed that the solid dispersion of CUR with PVP (CUR/PVP) at a 1:9 ratio, significantly increased (P < 0.05) solubility and permeability compared to CUR alone. Then, the antimicrobial activity of CUR/PVP, boric acid (BA), and a combination of 0.5% CUR/PVP and 0.5% BA (CUR/PVP-BA) against Salmonella Enteritidis (SE) was determined using an in vitro digestion model that simulates crop, proventriculus, and intestine. The results revealed that in the proventriculus and intestinal compartments significant reductions of SE were observed in all the experimental treatments, but 1% BA eliminated SE in the intestinal compartment and CUR/PVP-BA showed a synergistic effect on antimicrobial activity against SE. To complement these findings, two independent in vivo trials were conducted to determine the effect of 0.1% CUR/PVP; 0.1% BA; or the combination of 0.05% CUR/PVP (1:9 ratio) and 0.05% BA (CUR/PVP-BA) on the antimicrobial activity against SE, intestinal permeability and inflammatory responses in broiler chickens. BA at 0.1% had no significant in vivo effects against SE. However, the combination of 0.05% BA and 0.05% CUR/PVP and 0.05% BA was sufficient to reduce crop and intestinal SE colonization in broiler chickens in two independent trials, confirming the synergic effect between them. A similar antimicrobial impact against SE intestinal colonization was observed in chickens treated with 0.1% CUR/PVP at a 1:9 ratio, which could be due to the increase in solubility of CUR by PVP. Furthermore, 0.1% CUR/PVP reduced the intestinal permeability of FITC-d and total intestinal IgA, as well as increase the activity of SOD when compared to control, while, CUR/PVP-BA only decreased SOD activity. Further studies to confirm and expand the in vivo results obtained in this pilot study, adding intestinal microbial commensal groups and more inflammatory biomarkers to get a complete description of the effects of BA and CUR deserves further investigation.

This article is the first in a series of manuscripts to evaluate nutritional rehabilitation in chickens as a model to study interventions in children malnutrition (Part 1: Performance, Bone Mineralization, and Intestinal Morphometric Analysis). Inclusion of rye in poultry diets induces a nutritional deficit that leads to increased bacterial translocation, intestinal viscosity, and decreased bone mineralization. However, it is unclear the effect of diet on developmental stage or genetic strain. Therefore, the objective was to determine the effects of a rye diet during either the early or late phase of development on performance, bone mineralization, and intestinal morphology across three diverse genetic backgrounds. Modern 2015 (Cobb 500) broiler chicken, 1995 Cobb broiler chicken, and the Giant Jungle Fowl were randomly allocated into four different dietary treatments. Dietary treatments were (1) a control corn-based diet throughout the trial (corn–corn); (2) an early phase malnutrition diet where chicks received a rye-based diet for 10 days, and then switched to the control diet (rye–corn); (3) a malnutrition rye-diet that was fed throughout the trial (rye–rye); and (4) a late phase malnutrition diet where chicks received the control diet for 10 days, and then switched to the rye diet for the last phase (corn–rye). At 10 days of age, chicks were weighed and diets were switched in groups 2 and 4. At day 20 of age, all chickens were weighed and euthanized to collect bone and intestinal samples. Body weight, weight gain, and bone mineralization were different across diet, genetic line, age and all two- and three-way interactions (P

The purpose of this study was to evaluate the effect of humic acids (HA) on intestinal viscosity, leaky gut and ammonia excretion in a 24 hr feed restriction (FR) model to induce intestinal permeability in chickens. One-day-old male Cobb-Vantress broilers were randomly allocated to one of two groups (n = 25 chickens), with or without 0.2% of isolated HA from worm-compost, and placed in brooder batteries. Chicks had ad libitum access to water and feed for 14 days. Intestinal permeability was induced by 24 hr FR starting at 14 days. At 15 days of age, chickens in both groups were given an appropriate dose of fluorescein isothiocyanate dextran (FITC-d) by oral gavage. Intestine and liver samples were also collected to evaluate viscosity and bacterial translocation (BT), respectively. An increase (p < .05) in intestinal viscosity was observed in the experimental group consuming 0.2% of HA and was confirmed in a published in vitro digestion model that simulates the chemical and physical conditions of the crop, proventriculus and intestine of chickens. Furthermore, the treated group also showed a significant reduction in FITC-d, liver BT and ammonia in the manure. These results suggest that HA have a positive impact in intestinal integrity in chickens.

Fluorescein isothiocyanate dextran (FITC-d) is a 3-5kda marker used to measure tight junction permeability. We have previously shown that intestinal barrier function can be adversely affected by stress, poorly digested diets, or feed restriction, resulting in increased intestinal inflammation-associated permeability. However, further optimization adjustments of the current FITC-d methodology are possible to enhance precision and efficacy of results in future. The objective of the present study was to optimize our current model to obtain a larger difference between control and treated groups, by optimizing the FITC-d measurement as a biomarker in a 24 h feed restriction (FR) model to induce gut permeability in broiler chickens. One in vitro and four in vivo independent experiments were conducted. The results of the present study suggest that by increasing the dose of FITC-d, (8.32 mg/kg versus 4.16 mg/kg); shortening the collection time of blood samples, (1 h versus 2.5 h); using a pool of non-FITC-d serum as a blank, compared to previously used PBS; adding a standard curve to set a limit of detection and modifying the software’s optimal sensitivity value it was possible to obtain more consistent and reliable results.

Two experiments were conducted to evaluate the effect of the prophylactic or therapeutic administration of a 0.1% mixture containing ascorbic acid and a solid dispersion of curcumin with polyvinylpyrrolidone and boric acid (AA-CUR/PVP-BA) against Salmonella Enteritidis (S. Enteritidis) in broiler chickens. A third experiment was conducted to evaluate the impact of the dietary administration of 0.1% AA-CUR/PVP-BA in a necrotic enteritis (NE) model in broiler chickens. The prophylactic administration of 0.1% AA-CUR/PVP-BA significantly decreased S. Enteritidis colonization in cecal tonsils (CT) when compared to the positive control group (PC, p &lt, 0.05). The therapeutic administration of 0.1% AA-CUR/PVP-BA significantly reduced the concentration of S. Enteritidis by 2.05 and 2.71 log in crop and CT, respectively, when compared with the PC on day 10 post-S. Enteritidis challenge. Furthermore, the serum FITC-d concentration and total intestinal IgA levels were also significantly lower in chickens that received 0.1% AA-CUR/PVP-BA. Contrary, the PC group showed significantly higher total intestinal IgA levels compared to the negative control or AA-CUR/PVP-BA groups in the NE model. However, 0.1% AA-CUR/PVP-BA showed a better effect in reducing the concentration of S. Enteritidis when compared to the NE model. Further studies with higher concentration of AA-CUR/PVP-BA into the feed to extend these preliminary results are currently being evaluated.

The objectives of the present study were to evaluate the risks involved in the use of Enrofloxacin for Salmonella Enteritidis (SE) or Salmonella Heidelberg (SH) in commercial poultry and determine the effects of a probiotic as an antibiotic alternative. Two experiments were conducted to evaluate the risks involved in the use of Enrofloxacin for SE or SH in commercial poultry. Experiment 1 consisted of two trials. In each trial, chickens were assigned to one of three groups; control + SE challenged; Enrofloxacin 25 mg/kg + SE; and Enrofloxacin 50 mg/kg + SE. Chickens received Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, all groups received fresh water without any treatment. All chickens were orally gavaged with 10(7) cfu/chick of SE at 7 days of age and euthanized on 8 days of age. In Experiment 2, turkey poults were assigned to one of the three groups; control + SH; probiotic + SH; and Enrofloxacin 50 mg/kg + SH. Poults received probiotic or Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, poults received fresh water without any treatment. Poults were orally gavaged with 10(7) cfu/poult of SH at 7 days of age. Poults were weighed and humanely killed 24 h post-SH challenge to evaluate serum concentration of fluorescein isothiocyanate-dextran to evaluate intestinal permeability, metagenomics, and SH infection. In both trials of Experiment 1, chickens treated with Enrofloxacin were more susceptible to SE organ invasion and intestinal colonization when compared with control non-treated chickens (P 0.05). In Experiment 2, poults treated with 50 mg/kg of Enrofloxacin showed an increase in body weight, however, this group also showed an increase in SH susceptibility, intestinal permeability, and lower proportion of Firmicutes and Bacteroidetes, but with control group had the highest proportion of Proteobacteria. By contrast, poults that received the probiotic had the highest proportion of Firmicutes and Bacteroidetes, but lowest Proteobacteria. The results of the present study suggest that prophylactic utilization of Enrofloxacin at five times the recommended dose in poultry increases the susceptibility to salmonellae infections, and confirms that probiotics may be an effective tool in salmonellae infections.

Three experiments were conducted to evaluate the effect of in ovo administration of FloraMax®-B11 (FM) on Marek's disease (MD) herpesvirus of turkeys (HVT) vaccine protective efficacy, hatchability, microbiota composition, morphometric analysis, and Salmonella enteritidis (SE) infection in chickens. Experiment 1 consisted of 3 trials. In trials 1 and 2, d 18 White Leghorn 15I5x71 embryos were randomly distributed in 4 groups: 1) HVT vaccinated in ovo and no Marek's disease virus (MDV) challenge; 2), HVT + FM vaccinated in ovo and no MDV challenge; 3) HVT vaccinated in ovo and challenge with virulent MDV (vMDV; strain 583A); and 4), HVT + FM vaccinated in ovo and challenge with vMDV. Trial 3 was designed exactly the same as Experiment 1 but chicks were challenged with very virulent MDV (vvMDV; strains Md5 and 612). Birds were monitored until 8 wk of age, and tested for MD incidence. Experiment 2 consisted of 3 trials. In each trial, d 18 broiler embryos were injected in ovo with either saline or FM to measure hatchability and gastrointestinal bacterial composition. In Experiment 3, d 18 broiler embryos were injected in ovo with either saline or FM. All chickens that hatched were orally gavaged with SE at hatch and kept for 7 d to monitor post-hatch BW. No significant difference (P > 0.05) between MD percentage in birds vaccinated with HVT alone or HVT + FM were observed in Experiment 1. In Experiment 2, probiotic did not negatively affect hatchability, but did reduce lactose positive Gram-negative bacteria. Further, increase in BW was associated with higher villi surface area in the ileum in chickens that received the probiotic as well as a significant reduction in the SE incidence in Experiment 3. These results suggest that in ovo administration of FM does not negatively impact the ability of HVT to protect against MD or hatchability of chickens, but improves BW during the first 7 d of life and decreases SE recovery in chickens.