Nutritional Immunology

Transcription

1 Nutritional Immunology 288 Effect of Bacillus subtilis DSM on performance and gut pathology of broiler chickens in a necrotic enteritis challenge. Adebayo Sokale* 1, Anita Menconi 1, Kiran Doranalli 2, Gregory Mathis 3, and Brett Lumpkins 3, 1 Evonik Corporation, Nutrition & Care, Kennesaw, GA, 2 Evonik Nutrition & Care GmbH, Hanau, Germany, 3 Southern Poultry Research, Athens, GA. Clostridial diseases are among the most important cause of economic loss to poultry producers worldwide. Necrotic enteritis (NE) is an enteric disease of poultry caused by a pathogenic strain of Clostridium perfringens (CP). The production of CP toxins results in damage to the intestinal mucosa, resulting in pathology and loss of performance. Historically, antibiotic growth promoters (AGP) have been used to control NE. However with changes in the use of in-feed antibiotics, there is need to develop alternatives to control enteric pathogens. Direct-Fed Microbials (DFM) offer one alternative to AGP. Bacillus subtilis DSM is a unique DFM strain shown to inhibit the growth of pathogenic bacteria especially CP. A 28-d proof of concept trial was conducted to evaluate the effect of dietary inclusion of B. subtilis DSM compared with bacitracin methylene disalicylate (BMD) on gut pathology and performance of broilers challenged with a pathogenic strain of CP. The challenge was conducted using day-old broilers reared in cages. Birds were randomly assigned to 8 birds/cage, 10 cages/treatment and 4 treatment groups: uninfected control (UC), infected control (IC), B. subtilis DSM 32315, and BMD. The NE challenge was induced in each bird by oral inoculation with ~5,000 Eimeria maxima oocysts on d 13, followed by a NetB positive CP strain on 18, 19, and 20 doa. On d 20, intestinal tissues were obtained for histopathological examination. The intestinal tissues were evaluated for Coccidia Index (CI), Enteritis Index (EI) and Total Lesion Score (TLS). Overall, B. subtilis DSM significantly (P = 0.001) improved BW, and this improvement was similar to the UC and BMD groups. In addition, B. subtilis DSM numerically improved FCR by 3 points compared with the IC group. Mortality (P < 0.001) and lesion score (P < 0.001) were significantly lower in the B. subtilis DSM group compared with the IC group and was similar to the BMD group. The EI (P = 0.002) and TLS (P = 0.005) were significantly lower in the B. subtilis DSM compared with the IC group. This study indicates that dietary inclusion of B. subtilis DSM reduced enteritis associated gut pathology and improved performance similar to BMD, and therefore can be an effective preventive measure against NE. Key Words: direct-fed microbial, enteritis, performance, pathology 289 A polysaccharidic extract of Ulva sp. stimulates in vitro innate immunity in broilers. Maria Rodriguez*, Olmix, Brehan, Morbihan, France. Since microbial resistance to antibiotics is still increasing worldwide, more and more measures are taken to reduce antibiotic use. One example is the French plan Ecoantibio 2017, which aims at reducing the use of antibiotics in veterinary medicine by 25% within the next 5 years. This requires new strategies to be developed to support broilers immunity. Here we evaluate the effect of an extract of Ulva sp. harvested in Brittany (France), and rich in sulphated polysaccharides (MSP), on avian heterophils and monocytes in vitro. Heterophils and monocytes were purified from peripheral blood of 28 d-old, Ross 308 broilers raised in standard conditions. MSP induces the activation of heterophils via improvement of oxidative burst and glucuronidase activity in a dose and time-dependent manner (P < 0.05). In parallel, the ability of MSP to induce NO production in monocytes was assessed and it was also occurring in a time and dose-dependent manner. Both cell types responded in a range of MSP dose similar to the one of a usual activator. MSP allows in vitro stimulation of both heterophils and monocytes; being both cell types major players in broilers innate immunity. The mode of action of MSP is currently under study. The potential practical applications of this algal extract could be: enhancement of immunity and improvement of animal performance and the ultimate goal: the reduction of the use of antibiotics in animal production systems. Key Words: immunity, algal polysaccharides, MSP, immunomudulation, broiler 290 Effect of dietary supplemental daidzein on immune function in chickens. Hao Fan*, Zengpeng Lv, Liping Gan, and Yuming Guo, China Agricultural University, Beijing, China. Daidzein (DA) is an isoflavone, which is a hormone-like substance found in soybeans. The study found that it could improve the antioxidant capacity and immune function, besides regulate lipid metabolism and other effects. The effect of supplemental DA on chicken immune function were investigated. A total of week-old female broiler breeders were randomly divided into 3 treatment groups. These breeders were fed a controlled diet containing 0 mg/kg of DA (DA-deficient, DAD), 20 mg/kg of DA (DA-low-supplemented, DLS) or 100 mg/ kg of DA (DA-high-supplemented, DHS) for 8 weeks. Hatching eggs from 66-week-old hens were incubated. After hatching, offsprings were grouped the same as their mother to receive basal diet for 42 d. Blood and samples were obtained from hens, embryo and offsprings. The transcripts of the hens, embryos and offsprings were sequenced and the immune indexes were detected. The results showed that low level of DA would affect the immune performance of chickens. For hens, no treatment differences (P > 0.05) were detected in antibody titer, as well as the number of T cell subsets, however, the addition of 20 mg/ kg DA upregulated 47 different genes expression and downregulated 59 different genes expression(p < 0.05), it shown that addition of 20 mg/kg DA could enhance the expression of antimicrobial and humoral immune genes, and we also detected that the addition of 20 mg/kg DA could increase the levels of IgG and IgM in hens (P < 0.05). The addition of 100 mg/kg DA upregulated 82 different genes expression and downregulated 60 different genes expression (P < 0.05), resulting in decreased antibacterial capacity and humoral immune, and it could decrease the levels of IgG and IgM in hens (P < 0.05). Compared with the DAD and DHS group, the DLS group has a higher fertilization rate and a lower dead embryo rate. In offspring birds, the offspring birds from hens fed with DA 20 mg/kg had higher antibody titers and the IgA in blood significantly (P < 0.05), that from hens fed with DA 100 mg/ kg had lower levels of IgG and IgM (P < 0.05), and reduced expression of humoral immunity genes (P < 0.05), and antibody titers (P < 0.05) as well. It can be concluded that the dietary addition of 20 mg/ kg DA can improve the humoral immunity, and the ability of the hens to resist pathogens, and high level of DA addition at 100 mg/kg may be immune-depressive. The maternal effects of dietary DA for broiler breeders on the offspring is significant. Key Words: daidzein, transcriptions, immunity, breeder, offspring 108

2 291 Evaluation of the effects of probiotics on bacterial chondronecrosis with osteomyelitis lameness and antibiotics use in broiler chickens under commercial conditions. Eduardo Vicuna*, Biomin, San Antonio, TX. Bacterial chondronecrosis with osteomyelitis (BCO) is a common causes of lameness in broilers. Antibiotics are used to reduce it but with the emergence of bacterial resistance, it is important to find other ways to control the condition. The objectives of this work were to measure the efficacy of a probiotic (PoultryStar) in BCO lameness reduction. This trial was repeated for 2 flocks from 2 different breeder farms. The groups received basic diet or diet mixed with probiotics (0.5 kg/ton feed). On d 28 of the first flock, a post-mortem examination was performed to confirm BCO lesions and pododermatitis. Performance, mortality, lameness and antibiotics usage were recorded. No significant differences were found in BCO lesion or in pododermatitis scores between probiotics and control groups, however birds in the control group in both flocks had to be treated with antibiotics to control the incidence of BCO. BCO lesion scores were significantly different between breeder farms. Performance was different between the breeder farms. For one of the farms, lameness and mortality were higher in the probiotics group in the first flock but higher in the control group in the second flock. For the second farm, mortality in the first flock and lameness in both flocks were lower in the probiotics group. Slaughterhouse rejections were the lowest for the probiotics group. The findings suggest the prophylactic use of probiotics could be a strategy in controlling BCO and reducing antibiotics usage in poultry production. Key Words: probiotic, antibiotic, BCO lameness, broiler, performance 292 Graded levels of hulless barley and β-glucanase affect the digestive tract morphology of broiler chickens vaccinated for coccidiosis. Namalika Karunaratne* 1, Mike Bedford 2, Rex Newkirk 1, and Henry Classen 1, 1 University of Saskatchewan, Saskatoon, SK, Canada, 2 AB Vista, Marlborough, United Kingdom. Diet soluble β-glucan has previously been shown to adversely affect broiler performance, but these effects are largely eliminated by the use of the exogenous enzyme β-glucanase. How the digestive tract and other relevant tissues respond to the presence of soluble β-glucan and β-glucanase is of interest as it may help explain the mechanisms whereby these factors affect broiler productivity and health. The objective of the study was to evaluate the effect of hulless barley and β-glucanase on digestive tract morphology and key tissue weights in broiler chickens. Coccidiosis vaccinated broilers were fed graded levels of high β-glucan hulless barley (HB; CDC Fibar; 0, 30 and 60% replacing wheat) and β-glucanase (BG; Econase GT 200P; 0, 0.01 and 0.1%) in a 3 3 factorial arrangement (RCBD). A total of 5,346 mixed sex broilers were raised in litter floor pens and vaccinated in feed and water on d 5 with Coccivac- B52 (Merck Animal Health). Each treatment was assigned to 1 pen in each of 9 rooms and there were 66 birds per pen. Digestive tract segment weights, lengths and contents, and organ weights were obtained at d 11 and 33. Statistical significance level was considered as P At d 11, relative empty weights (proventriculus, gizzard, jejunum, colon and pancreas), lengths (jejunum and colon) and contents (gizzard, jejunum and colon) increased with HB and relative empty weights (proventriculus and colon), length (colon) and contents (jejunum and colon) decreased with BG. At d 33, relative empty weights (gizzard, duodenum, jejunum, ceca, colon, pancreas and liver), lengths (duodenum, ceca and colon) and contents (gizzard, ileum, ceca and colon) increased with HB and relative empty weights (colon and liver) and contents (jejunum, ileum and colon) decreased with BG. Significant interactions were observed for contents (crop, duodenum, ileum and ceca) and liver at d 11 and, lengths (jejunum and ileum) at d 33. In conclusion, over the entire experiment, HB increased digestive tract size and content, whereas BG reduced them by increasing digestive function. Further research is required to determine how soluble β-glucans and lower weight polymers resulting from BG change the gut microbial community and affect gut health. Key Words: enzyme, prebiotics, oligosaccharide, β-glucan, digestion 293 Effects of replacing antibiotics and anticoccidials with probiotics in broiler diets on intestinal coccidial lesion development. Wei Zhai*, Kacey O Donnell, and Xi Wang, Mississippi State University, Mississippi State, MS. The current trial was conducted to study the effects of dietary antimicrobials (50g bacitracin/ton of feed as the antibiotic, and 54g narasin/ ton of feed as the anticoccidial) and probiotics (Bacillus subtilis, 30,000 spores/g feed) on intestinal coccidial lesion development of broilers challenged with live Eimeria (E.) oocysts. A total of 640 male Ross Ross 708 broilers were divided into 5 dietary treatments, 8 replications, with 16 birds in each floor pen and raised to 35 d of age. The 5 dietary treatments were 1) basal diet (as negative control, NC); 2) basal diet supplemented with bacitracin from d 0 to 14, bacitracin and narasin from d 14 to 35 (antimicrobials, Anti); 3) Bacillus subtilis (probiotics, Pro); 4) bacitracin from d 0 to 14, and bacitracin withdrew from d 14 to 35 (Anti+NC); and 5) bacitracin from d 0 to 14, and Bacillus subtilis from d 14 to 35 (Anti+Pro). On d 14, all the birds were orally gavaged with 10 dose of commercial coccidial vaccine including E. acervulina, E. maxima, E. maxima MFP, E. mivati, and E. tenella. One bird from each pen was necropsied every week for 3 weeks after challenge. Lesions were scored on duodenum, jejunum, ileum, and ceca. The lesion scoring was analyzed using one-way nonparametric Wilcoxon analysis using Proc NPAR1WAY of SAS 9.4. Seven days after challenge, Anti reduced duodenal lesions as compared with NC (P = 0.074) and Anti+NC (P = 0.009). Fourteen days after challenge, Pro lowered duodenal lesions as compared with NC (P = 0.015) and Anti (P = 0.054). Twenty-one days after challenge, even though the lesions were not significantly different among dietary treatments (P = 0.133), the duodenums of birds fed Anti and Pro had fully recovered from the lesions (i.e., lesion scores had been reduced to zeros). The lesions in the duodenum were caused by E. acervulina with the appearance of white plaque-like spots. Pro lowered ileal lesions as compared with NC (P = 0.074). The lesions in the ileum were caused by E. maxima with the appearance of small red petechial. In conclusion, both antimicrobials and Bacillus subtilis facilitated the birds in inhibiting coccidial lesion development and recovering from the lesions. However, the birds fed antimicrobials and Bacillus subtilis exhibited different patterns of lesion development and recovery, which may be due to different mechanisms of how these supplements control the intestinal microflora environment. Key Words: antibiotic, anticoccidial, broiler, coccidiosis, probiotic 294 Supplemental dietary microalgal astaxanthin affects hepatic gene expression related to redox status, heat stress, inflammation, and lipid metabolism in laying hens. Samar Tolba* 1, Andrew Magnuson 1, Tao Sun 1, Sandip Shinde 2, and Xingen Lei 1, 1 Cornell University, Ithaca, NY, 2 Heliae, Gilbert, Germany. We have recently demonstrated a dose-dependent elevation of oxygen free radicals absorbance in the liver and egg yolk of laying hens fed astaxanthin-rich microalgae. This study was to determine how the supplemental astaxanthin affected mrna expression of key genes 109

3 involved in antioxidant activity, heat stress, inflammation, and lipid metabolism. White Leghorn Shaver hens (Total = 50 and 21-wk old) were divided into 5 treatment groups, reared individually in cages (10 cages/treatment) and fed corn-soybean meal basal diet supplemented with microalgal (Haematococcus pluvialis) astaxanthin (Heliae, Gilbert, AZ) at 0, 10, 20, 40, and 80 mg/kg for 6 wk. Liver samples (n = 5/treatment) were collected at the end of study for the gene expression analyses. Data were analyzed by one-way ANOVA. Compared with the control diet, the 20 and 40 mg astaxanthin/kg diets upregulated (P < 0.05) the mrna expression of superoxide dismutase-1 (113%) and glutathione reductase (23%) respectively. The 20 mg astaxanthin/ kg diets upregulated the mrna expression of serine/threonine kinase (99%), and mitogen activated protein kinase P38 MAPK (60%), while the 40 mg astaxanthine/kg diets upregulated the mrna expression of heat shock protein-90 (34%), heat shock protein-70 (125%), along with a 60% downregulation (P < 0.05) of interlueken-10. The 80 mg astaxanthin/kg diet downregulated (P < 0.05) mrna expression of key lipogenesis genes: fatty acid synthase (63%), acetyl Co-A carboxylase (61%), stearoyl Co-A desaturase (45%), and diacylglycerol acyltransferase (44), along with an enhanced mrna of the lipolysis gene carnitine palmitoyltranferase (230%), compared with the control. In conclusion, supplemental dietary microalgal astaxanthin exerted a dose-dependent, but nonlinear, effect on hepatic gene expression involved in controlling redox status, oxidative and heat stress, inflammation, and lipid metabolism of laying hens. Supported by DOE (DE-EE ), Cornell University (Hatch grant NYC ). Key Words: antioxidant, cytokine, gene expression, lipid metabolism, poultry 295 Effect of xylanase, probiotics and their combination on broiler performance, intestinal lesion observation in response to Eimeria and Clostridium perfringens challenges. Basheer Nusairat* 1, James McNaughton 2, Fang Zhou 1, and Jeng-Jie Wang 1, 1 BioResource International Inc., Durham, NC, 2 AHPharma Inc., Hebron, MD. This study was conducted to evaluate the effects of xylanase (Xylamax, BioResource International Inc.), probiotics, and their combination on performance and under mild subclinical challenge with 2 Eimeria species and C. perfringens in broilers raised to 42 d. A total of 2,496 Ross 708 broiler chicks were assigned to 48 floor pens with 52 birds per pen. A total of 6 dietary treatments were used in the starter (0 21 d), grower (22 35 d), and finisher (36 42 d) phases. Treatment diets were corn-soy based and contained 1) no xylanase or probiotics (control), 2) xylanase only, 3) probiotic A only, 4) probiotic B only, 5) xylanase plus probiotic A, or 6) xylanase plus probiotic B. Data were analyzed as randomized complete block design. When compared with control at 42 d, the xylanase, probiotic A, and probiotic B improved (P < 0.05) BW gain by 93, 94, and 53 g, respectively, and FCR by 4, 4, and 6 points, respectively. When compared with control at 42 d, the combination of xylanase and probiotic A or probiotic B improved (P < 0.05) BW gain by 142 or 147 g, respectively and FCR by 9 or 11 points, respectively. The combination of xylanase and probiotic A or probiotic B reduced (P < 0.05) body weight coefficient of variation from control (15.09%) to 8.27% or 8.22%, respectively at 42 d. The combination of xylanase and probiotic A or probiotic B reduced (P < 0.05) gross lesion scores in small intestine at 42 d compared with control (1.21) to 0.43 or 0.26, respectively. The combination of xylanase and probiotic A or probiotic B reduced (P < 0.05) C. perfringens count at 42 d from control (4.06) to 2.51 or 2.57 log 10 cfu/g of digesta respectively. Results suggest that the xylanase and probiotics alone can improve broiler performance and 110 reduce the disease severity due to Eimeria and C. perfringens challenges, and that the effect of xylanase and probiotics are additive. Key Words: broiler, xylanase, probiotics, Clostridium perfringens, Eimeria 296 Evaluation of the effect of a novel Bacillus subtilis (CHCC15076) probiotic strain on chickens subjected to physiological intestinal inflammation. Alfred Blanch* 1, Dorthe Sandvang 1, Line Skjoet-Rasmussen 1, Mickael Rouault 1, Jaime Sánchez 2, and Marta Gracia 2, 1 Chr. Hansen A/S, Hørsholm, Denmark, 2 Imasde Agroalimentaria S.L, Pozuelo de Alarcón, Spain. The aim of this study was to evaluate the addition of a new DFM (Bacillus subtilis, strain CHCC15076, hereinafter referred to as KG76) in diets for chickens subjected to physiological intestinal inflammation. 1,800 Ross 308 male broilers were randomly allocated in 72 floor-pens, each containing 25 birds, distributed in 6 dietary treatments (12 pens per treatment): basal diet without any DFM (T1), basal diet + KG76 at cfu/kg feed (T2), basal diet + KG76 at cfu/kg feed (T3), basal diet + KG76 at cfu/kg feed (T4), basal diet + KG76 at cfu/kg feed (T5), basal diet + KG76 at cfu/kg feed (T6). Diets where administered ad libitum during 3 phases: starter (1 to 14 d), grower (14 to 28 d) and finisher (28 to 42 d) Basal diet was based on corn, wheat, barley, rye and soybean meal and without any added enzyme. Growth, body weight, feed intake, and feed conversion (FCR) were evaluated at 1, 14, 28 and 42 d of age. Data were analyzed as a completely randomized design by GLM of SPSS v followed by Tukey s mean test. Total mortality/cull at 42 d was 3.56%, without significant differences among experimental treatments. During the starter period, no significant differences between treatments were observed. At 28 d, birds receiving KG76 at and (T4 and T5) were 8.65% heavier than control birds. During the grower period, chickens from T4, T5 and T6 grew significantly more than control birds (66.1, 67.8, 68.8, 72.6, 74.1 and 71.9 g/d for T1 to T6, respectively, P < 0.05). At 42 d, birds supplemented with KG76 at (T5) were significantly heavier than control birds (P < 0.05). For the overall fattening period, birds supplemented with KG76 at (T5) grew significantly more than control birds (T1), showing the other doses intermediate growth (61.7, 61.9, 62.6, 64.3, 64.9 and 63.1 g/d for T1 to T6, respectively, P < 0.05). Furthermore, FCR and EPEF were significantly improved by treatment, showing broilers supplemented with KG76 at and (T4 and T5) the highest values for both parameters. Under this trial conditions, it can be concluded that supplementation of broiler diets with KG76 improves performance of birds with intestinal inflammation, when added at doses between and cfu/kg feed. Key Words: DFM, Bacillus, chicken, inflammation 297 Titratable effects of AviLution on cecal bacteria in broiler chickens during infection with Clostridium perfringens. Lucas Krueger* 1, David Spangler 1, and Michael Sims 2, 1 Agri-King Inc., Fulton, IL, 2 VA Diversified Research, Harrisonburg, VA. The objective of the present study was to observe titratable responses in the relative abundance of cecal bacteria upon dietary supplementation of 3 levels of Avi-Lution. Avi-Lution is a commercially available probiotic that contains approximately combined colony forming units (cfu) per g of Saccharomyces cerevisiae, Enterococcus faecium, and Bacillus spp. Male, Cobb 500 broilers (n = 1,800 broilers; 10 pens per treatment; 30 broilers per pen) were raised for 42 d in floor

4 pens and subjected to one of 6 treatments, which were un-inoculated control (UC), inoculated by oral gavage on d 17 of age with cfu Clostridium perfringens (IC; 0 mg/kg AvL), inoculated with C. perfringens (Cp) and supplemented with Avi-Lution in feed at a rate of 250 mg/kg (AvL250), 375 mg/kg (AvL375), or 500 mg/kg (AvL500), or inoculated and supplemented from d 10 31with avilamycin at 20 mg/kg in feed (AVM) as a performance control. Linear Pearson coefficients were determined for the relationships of AvL dose to the relative abundances of 16S gene-based bacterial operational taxonomic units (OTU) in cecal contents at d 14, 28, and 42 of age. Those OTU found to be negatively related to AvL dose (Pearson coefficient with P < 0.05) were expressed as a percentage of bacterial communities in IC samples (AvL at 0 mg/kg), whereas positively correlated OTU were expressed as a percentage of AvL500 (highest dose) bacterial communities. Negatively correlated OTU comprised 2.93 ± 1.20% of bacterial sequences at d 14 of age (pre-cp inoculation), ± 1.64% of sequences at d 28 (post-cp inoculation), and 3.39 ± 0.78% of sequences at d 42 in IC samples. Positively correlated OTU were not detected at d 14, but comprised ± 0.21% and 2.11 ± 0.46% of sequences at d 28 and 42, respectively, in AvL500 samples. These findings demonstrate that Avi-Lution affected cecal bacteria in a dose-dependent manner during infection with C. perfringens. Key Words: Clostridium perfringens, necrotic enteritis, broiler, probiotic, bacterial community 298 Vaccine to fibroblast growth factor 23 peptides increases eggshell strength. Zhouzheng Ren*, Alexis Piepenburg, Daniel Bütz, James Claus, and Mark Cook, University of Wisconsin-Madison, Madison, WI. Strategies that would increase eggshell quality could be of considerable value to egg producers. Here we demonstrate the effective use of fibroblast growth factor 23 (FGF-23) peptide vaccines to increased eggshell quality of Single Comb White Leghorn laying hens (68-wkold). Hens, fed a standard diet (containing 900 IU/kg vitamin D 3 ), were intramuscularly injected (and boosted) with either a control vaccine (n = 14 hens), or one of 2 FGF-23 peptide vaccines (peptides NP1, GMNPPPYS; and NP7, YTSTERNSFH; n = 15 hens for each peptide). During peak antibody titer, eggs were collected for shell and internal quality analysis, hens were artificially inseminated and the hatchability of fertilized eggs was determined. Eggs from laying hens vaccinated with either FGF-23 peptide NP1 or NP7 had increased (P 0.001) specific gravity (NP1 = 1.082, NP7 = 1.083, control = 1.079), shell strength (g of force, NP1 = 3995, NP7 = 4153, control = 3093), shell weight (g, NP1 = 7.4, NP7 = 7.4, control = 7.0), and shell index (% of whole egg, NP1 = 13.5, NP7 = 13.3, control = 13.0) when compared with eggs from control vaccinated hens. FGF-23 peptide NP1 vaccinated hens also had increased shell thickness (P 0.001), egg weight (P = 0.014) and yolk weight (P = 0.014), and decreased albumen index (P = 0.050) when compared with control vaccinated hens. FGF-23 peptide NP7 vaccinated hens had decreased yolk index (P = 0.011), and increased albumen weight (P = 0.035) when compared with control vaccinated hens. Dry matter content of yolk, albumen, shell and the total egg were not affected by FGF-23 peptide vaccinations (P > 0.05). Hatchability of fertilized eggs was not affected by FGF-23 peptide vaccinations (P > 0.05). In conclusion, vaccines to FGF-23 peptides increased eggshell quality of 68-wk-old laying hens with no adverse effects on egg internal quality and hatchability. Key Words: fibroblast growth factor 23, antibody, specific gravity, shell strength, egg breakage 299 Investigation of the dietary direct-fed microbials as an antibiotic alternative on growth, gut immunity and epithelial barrier protein expression in young broiler chickens. Sungteak Oh*, Ujvala Gadde, Youngsub Lee, and Hyun Lillehoj, USDA-ARS, Beltsville, MD. The objective of this study was to investigate the effects of Bacillus subtilis-based probiotic supplementation in broiler chicken diets on growth performance, feed efficiency, intestinal cytokine and tight junction (TJ) protein mrna expression. Day-old broiler chicks (n = 140) were randomly assigned to one of 5 dietary treatments: basal diet (CON), basal diet supplemented with antibiotic (BMD) or probiotics, namely B. subtilis strain 1781 (PB1), a combination of B. subtilis strain 1104+strain 747 (PB2) or B. subtilis strain 1781+strain 747 (PB3). Body weight and feed intake were measured at 14 d of age, and the feed conversion ratio (FCR) was calculated. At 2 weeks of age, ileal samples were collected and used for intestinal cytokine, TJ protein and mucin gene expression analysis using qrt-pcr. The antibiotic (BMD) supplemented group and B. subtilis strain 1781 alone (PB1) group had significantly higher body weights compared with controls (P-value = ). Dietary supplementation with antibiotic (BMD) or probiotics (PB1, PB2, PB3) significantly improved the feed efficiency as evidenced by decreased FCR compared with controls (P-value = ). No differences were observed in the expression of IL1β, IL17F, IFNγ and MUC2 gene among the different treatment groups. However, elevated expression of IL6 (P-value = ), IL8 (P-value = ) and TNFSF15 (P-value = ) compared with controls was observed in the ileum. IL2 (P-value = ) and IL10 (P-value = ) expression was upregulated in chicks in the PB2 and PB3 groups, and IL4 (P-value = ) was elevated in the PB1 group. IL13 (P-value = ) was elevated in all probiotic-fed groups (PB1, PB2, PB3). Probiotic supplementation was also shown to significantly increase the expression of TJ proteins JAM2 (P-value = ), ZO1 (P-value = ) and occludin (P-value = ). Taken together, B. subtilis supplementation altered intestinal immune activity and influenced gut barrier integrity through increased expression of TJ proteins Key Words: chicken, Bacillus subtilis, gut 300 Performance of broiler chickens fed Bacillus subtilis DSM and an antibiotic growth promoter in a necrotic enteritis challenge. Anita Menconi* 1, Adebayo Sokale 1, Kiran Doranalli 3, and Michael Sims 2, 1 Evonik Corporation, Kennesaw, GA, 2 VA Diversified Research, Harrisonburg, VA, 3 Evonik Nutrition & Care GmbH, Hanau, Germany. Necrotic enteritis (NE) is a multifactorial enteric disease of poultry caused by a pathogenic strain of Clostridium perfringens (CP). Under commercial conditions, NE often causes high mortality and lower performance, resulting in considerable economic loss. Direct-Fed Microbials (DFM) have been studied as a tool to aid in the control of NE in broilers raised without antibiotics due to the potential to maintain a stable gut microbiota, which, in turn, can reduce enteric diseases and improve growth performance. An experiment was conducted with the objective to evaluate the effects of a unique DFM strain, Bacillus subtilis DSM 32315, in comparison to bacitracin methylene disalicylate (BMD) on controlling NE in broilers under a CP challenge. Day-old chicks were randomly distributed in floor pens, with 12 replicates of 30 birds/pen and raised for 42 d. The experiment consisted of 4 treatment groups: non-challenged control, challenged control, DFM at cfu/g feed, and BMD at 50g/MT. On d 17, 18, and 19, birds from challenged control, DFM, and BMD groups were individually challenged via oral gavage with 2 ml ( cfu/ml) of CP (type A β hemolytic isolate). 111

5 All birds and feeds were weighed at d 14, 28, and 42. NE lesion scores were recorded at 21 d and mortality was recorded daily. At d 14, no significant differences in body weight and mortality were observed. However, DFM supplemented birds showed a significantly (P < 0.05) lower feed conversion ratio (FCR) at d 14 compared with challenged control and BMD. At d 21, DFM and BMD significantly (P < 0.05) decreased the average NE lesion score compared with challenged birds. At d 42, DFM, similar to BMD, significantly (P < 0.05) improved body weight and FCR. DFM fed group had a significantly (P < 0.05) lower NE related mortality and a numerically lower overall mortality compared with challenged control. Furthermore, DFM group showed a significant (P < 0.05) improvement in European Poultry Efficiency Factor. Overall, this experiment showed that dietary inclusion of B. subtilis DSM reduced NE lesions scores and associated mortality, improved weight gain and FCR, and reduced mortality from all causes, comparably to a standard antibiotic growth promoter. Key Words: broiler, Clostridium perfringens, direct-fed microbial, necrotic enteritis 301 Effects of Mentofin on humoral immune response and bursal morphology against Infectious bursal disease in broiler chickens. Muhammad Umair Shah, Asim Aslam*, Ghulam Mustafa, Ali Ahmed Sheikh, and Gulbeena Saleem, University of Veterinary and Animal Sciences, Lahore, Punjab, Pakistan. Infectious bursal disease (IBD) is one of the important viral disease causing huge economic losses mainly because of immunosuppression in chickens. A study was conducted to evaluate the effect of Mentofin (a herbal product) on humoral immune response and bursal tissue morphology in conjunct with IBD virus vaccine in broiler chickens. A total 360 broiler chickens were divided into 4 equal groups (A-D) with 5 replicates of 20 birds each. All the birds were reared under controlled environmental conditions. All the birds of groups A and B were vaccinated with the IBD live virus vaccine at d 0. Birds of Group B were treated with 0.25mL/L of drinking water during d 0 42 in addition to vaccination. Birds of Group C were given Mentofin only. While Group D served as negative control. On d 0, , 28 and 42 5 birds from each replicate were randomly selected and killed humanely for post-mortem examination, bursa/ body weight ratio and histopathological studies. Prior to necropsy blood was also collected from these birds on all experimental days to record weekly serum antibody response against IBD. Results showed that significantly (P < 0.05) higher ELISA antibody titer was observed in Group B (vaccinated and treated with Mentofin) on all experimental days as compared with all other groups. No gross pathology was observed in any of the group. However in most of birds from vaccinated groups (A and B) bursa had large size as compared with non- vaccinated groups (C and D). Histopathology revealed varying degree of lymphoproliferative changes in bursa of Fabricius with increased number of lymphocytes in Group B. Mild lymphocytic depletion was observed in birds of Group A. Bursa/ body ratio was highest (P < 0.05) in birds of Group B on all experimental days whereas lowest in birds of Group D. It was concluded that Mentofin supplementation may have potent immunomodulatory effect in chickens when vaccinated against IBD. Key Words: infectious bursal disease (IBD), Mentofin, bursa of Fabricius, histopathology, humoral immunity 112