Oral antibodies to human intestinal alkaline phosphatase reduce dietary phytate phosphate bioavailability in the presence of dietary 1α-hydroxycholecalciferol

Sequencing approaches to identify distal jejunum microbial community composition and function in broiler chickens fed anti-interleukin-10 during coccidiosis and necrotic enteritis challenge

Strategies to counteract interleukin (IL)-10-mediated immune evasion by Eimeria spp. during coccidiosis- like anti-IL-10 antibodies- may protect broiler chicken health and reduce incidence of secondary necrotic enteritis (Clostridium perfringens) via undetermined mechanisms. Objectives were to use sequencing techniques to evaluate jejunal microbial community composition and function in anti-IL-10-fed broilers during coccidiosis and necrotic enteritis. On d0, Ross 308 chicks were placed in 32 cages (15 chicks/ cage) for a 25-d study and randomly assigned to diets ± 0.03% anti-IL-10. Six chicks/ diet were euthanized for distal jejunum content and tissue collection on d 14 (baseline) before inoculating the remainder with saline or 15,000 E. maxima oocysts (M6 strain). Half the chicks challenged with E. maxima were challenged with C. perfringens (1×108 colony forming units) on d 18 and 19. Follow-up samples (6 chicks/treatment) were collected at 7 and 11 d postinoculation (pi) for the E. maxima-only group, or 3 and 7 dpi for the E. maxima + C. perfringens group with 3/7 dpi being designated as peak and 7/11dpi as postpeak challenge. DNA was extracted from digesta for microbiota composition analysis (16S rRNA gene sequencing) while RNA was extracted from tissue to evaluate the metatranscriptome (RNA sequencing). Alpha diversity and genus relative abundances were analyzed using the diet or challenge main effects with associated interactions (SAS 9.4; P ≤ 0.05). No baseline microbial changes were associated with dietary anti-IL-10. At peak challenge, a diet main effect reduced observed species 36.7% in chicks fed anti-IL-10 vs. control; however, the challenge effect reduced observed species and Shannon diversity 51.2-58.3% and 33.0 to 35.5%, respectively, in chicks challenged with E. maxima ± C. perfringens compared to their unchallenged counterparts (P ≤ 0.05). Low sequencing depth limited metatranscriptomic analysis of jejunal microbial function via RNA sequencing. This study demonstrates that challenge impacted the broiler distal jejunum microbiota more than anti-IL-10 while future research to characterize the microbial metatranscriptome may benefit from investigating other intestinal compartments.

Ileal phosphorus digestibility of soybean meal for broiler chickens remains consistent across institutions in a collaborative study regardless of non-phytate phosphorus concentration in the pre-experimental starter diet

The same experimental protocol was used in 4 institutions to evaluate the impact of non-phytate phosphorus (nPP) concentration in the starter diet on regression method-derived ileal P digestibility of soybean meal (SBM) during the subsequent grower phase. A total of 1,536 Ross 308 male broiler chickens on d 0 post hatching were allotted to 2 pre-experimental starter diets that contained 3.5 or 4.5 g nPP/kg (96 replicate cages per diet, 8 birds per cage) for 18 d. Subsequently, 576 birds from each starter diet were selected and allocated to 3 experimental semi-purified grower diets containing 400, 510, or 620 g SBM/kg (32 replicate cages per diet, 6 birds per cage) for 3 d until collection of ileal digesta. Statistical analysis was conducted as a randomized complete block design with the starter period as whole plot and the grower period as split-plot. The only significant 2-way interaction was between grower diet and experimental institution (P < 0.05) on BW gain and gain to feed ratio. The main effect of institution and grower diet impacted (P < 0.05) feed intake, the digestibility of DM, P, and calcium, and disappearance of inositol hexakisphosphate (InsP6) in the grower diets. Birds fed the 3.5 g nPP/kg starter diet had lower (P < 0.05) BW gain and feed intake during the grower period, but presented higher (P < 0.05) digestibility of P and disappearance of InsP6 compared with the birds that were fed the 4.5 g nPP/kg starter diet. Regression method-derived ileal P digestibility of SBM was determined to be 46 or 42% for the respective 3.5 or 4.5 g nPP/kg pre-experimental starter diet and was not affected by the nPP concentration or by the institution. In conclusion, the experimental protocol used in the current study resulted in similar estimates across multiple institutions and is thus endorsed for future application in studies that aim to expand the database of digestible P content in plant source feed ingredients.

Coccidiosis and necrotic enteritis model may have a greater impact than dietary anti-interleukin-10 on broiler chicken systemic immunometabolic responses

Dietary egg yolk-derived anti-interleukin (IL)-10 may preserve broiler chicken performance during coccidiosis due to Eimeria spp. infection while effects on secondary Clostridium perfringens (necrotic enteritis) are unknown. Some necrotic enteritis models implement Salmonella Typhimurium to improve repeatability; however, Salmonella upregulation of IL-10 may be a confounder when evaluating anti-IL-10. The study objective was to investigate anti-IL-10 effects on systemic cytokine concentrations and immunometabolism during E. maxima ± C. perfringens challenge in models ± S. Typhimurium. Three 25 d replicate studies using Ross 308 chicks were conducted in wire-floor cages (32 cages/ replicate) with chicks assigned to diets ± 0.03% anti-IL-10. 640 chicks (20/ cage; replicates 1 and 2) were inoculated with sterile saline ± 1×108 colony forming units (CFU) S. Typhimurium while 480 chicks (15/ cage) were placed in replicate 3. In all replicates, blood samples were collected on d 14 (6 chicks/treatment) before administering 15,000 sporulated E. maxima M6 oocysts to S. Typhimurium-inoculated (replicates 1 and 2) or challenge-designated chicks (replicate 3). Half the E. maxima-challenged chicks received 1×108 CFU C. perfringens on d 18 and 19. Blood samples were collected at 1, 3, 7, and 11 d post-inoculation (dpi) with E. maxima and 1, 3, and 7 dpi with secondary C. perfringens. Plasma cytokines were determined by ELISA while immunometabolic assays evaluated peripheral blood mononuclear cell ATP production and glycolytic rate responses. Data were analyzed with diet and challenge fixed effects plus associated interactions (SAS 9.4; P ≤ 0.05). Replicates 1 and 2 showed few immunometabolic responses within 3 dpi with E. maxima, but 25 to 31% increased ATP production and 32% increased compensatory glycolysis at 1 dpi with C. perfringens in challenged vs. unchallenged chicks (P ≤ 0.04). In replicate 3, total ATP production and compensatory glycolysis were increased 25 and 40%, respectively, by the E. maxima main effect at 1dpi (P ≤ 0.05) with unobserved responsiveness to C. perfringens. These outcomes indicate that model type had greater impacts on systemic immunity than anti-IL-10.

Early Salmonella Typhimurium inoculation may obscure anti-interleukin-10 protective effects on broiler performance during coccidiosis and necrotic enteritis challenge

Anti-interleukin (IL)-10 may preserve broiler performance during coccidiosis by diminishing Eimeria spp. host-evasion but has not been evaluated during secondary Clostridium perfringens challenge (necrotic enteritis). Early Salmonella Typhimurium inoculation is implemented in some models to improve repeatability-a potential confounder due to Salmonella using similar IL-10 host evasion pathways. The objective was to evaluate performance and disease outcomes in broilers fed anti-IL-10 during necrotic enteritis challenge ± S. Typhimurium. Three 42 d replicate studies in wire-floor cages (32 cages/replicate) were conducted with Ross 308 chicks assigned to diets ± 0.03% anti-IL-10 for 25 d before moving to floor pens for the study remainder. In replicates 1 and 2, 640 chicks were placed at hatch (20/cage) and inoculated with sterile saline ± 1 × 108 colony forming units (CFU) S. Typhimurium. Replicate 3 placed 480 chicks (15/cage) at hatch. On d 14, S. Typhimurium-inoculated chicks (replicates 1 and 2) or those designated for challenge (replicate 3) were inoculated with 15,000 sporulated Eimeria maxima M6 oocysts. On d 18 and 19, half the E. maxima-challenged chicks were gavaged with 1 × 108 CFU C. perfringens. Body weight (BW) and feed intake were measured throughout, while 6 chicks/ treatment were scored for jejunal lesions at 7 and 3 d postinoculation (pi) with E. maxima and C. perfringens, respectively. Oocyst shedding was measured at 8 and 4 dpi with E. maxima and C. perfringens, respectively. Performance and oocyst shedding were analyzed with diet and challenge fixed effects (SAS 9.4), whereas lesion scores and mortalities were analyzed by ordinal logistic regression (R 4.2.2; P ≤ 0.05). In replicate 3, no wk 3 feed conversion ratio (FCR) differences were observed between chicks fed anti-IL-10 challenged with E. maxima ± C. perfringens, whereas control-fed chicks had a 50 point less efficient FCR during E. maxima + C. perfringens challenge vs. E. maxima only (P = 0.04). Outcomes suggest anti-IL-10 may preserve bird feed efficiency during necrotic enteritis challenge in models without S. Typhimurium.

Dietary peptide-specific antibodies against interleukin-4 differentially alter systemic immune cell responses during Eimeria challenge with minimal impacts on the cecal microbiota

Eimeria spp. induce host interleukin (IL)-4 production, a potent immune regulator, during coccidiosis to evade immune responses. Dietary anti-IL-4 may preserve bird performance during challenge; however, specific mechanisms have not been investigated. Study objectives were to develop peptide-specific anti-IL-4 antibodies and evaluate immune cell profiles and the cecal microbiota during Eimeria challenge. Four candidate IL-4 peptides were selected based on antigenicity and location. Hens were injected with conjugated peptide or carrier-only control (3/injection), eggs were collected post-vaccination and yolks were pooled by peptide before freeze-drying. On d 0, 300 Ross 708 broilers were placed in floor pens (10/pen) and assigned to 5 diets consisting of basal diet + 2% egg yolk powder containing antibodies against 1 of 4 target peptides or carrier-only control for 14-d starter and grower periods (28 d total). Baseline blood and cecal contents were collected on d 14 (6 birds/diet) before half the remainder were inoculated with 10X Coccivac-B52 (Merck Animal Health, Kenilworth, NJ). Body weight (BW) and feed intake (FI) were recorded weekly and blood and cecal samples were collected at 3, 7, and 14 d post-inoculation (pi; 3/treatment). Immune cell profiles in peripheral blood mononuclear cells (PBMC) were evaluated flow cytometrically and cecal microbial communities determined by 16S/18S rRNA gene amplicon sequencing. Data were log-transformed when necessary and analyzed with diet, Eimeria, and timepoint fixed effects plus associated interactions (SAS 9.4; P ≤ 0.05). Anti-IL-4 did not alter baseline performance but generally increased PBMC Bu-1+ B cells 38.0 to 55.4% (P < 0.0001). Eimeria challenge reduced FI and BWG 16.1 and 30.3%, respectively, regardless of diet (P < 0.0001) with only birds fed peptide 4 antibodies not recovering feed conversion by d 28. Minimal diet-associated cecal microbiota changes were observed, indicating that anti-IL-4 effects were likely host-specific. Eimeria-challenged birds fed peptide 3 antibodies displayed minimal immune cell fluctuations compared to unchallenged counterparts, suggesting these antibodies potentially modulated intestinal immune responses to minimize systemic requirements, making them good candidates for further research.

Dietary supplementation of sulfur amino acids improves intestinal immunity to Eimeria in broilers treated with anti-interleukin-10 antibody

Oral antibody to interleukin-10 (anti-IL-10) enhances the intestinal immune defense against Eimeria. The sulfur amino acids methionine and cysteine (M+C) play essential roles in inducing and maintaining protective immune responses during intestinal infections. Hence, increased dietary M+C may support the anti-IL-10-induced intestinal immunity to Eimeria. Broilers (n = 640) were arranged in a 2 × 2 × 2 factorial design with 2 levels of each of the 3 main factors: dietary standardized ileal digestible (SID) M+C levels (0.6% or 0.8%), dietary anti-IL-10 supplementation (with or without), and coccidiosis challenge (control or challenge). Briefly, the broilers were supplied with either 0.6% or 0.8% SID M+C, each with or without anti-IL-10 (300 μg/kg), from d 10 to 21. On d 14, broilers from each diet were gavaged with either PBS or Eimeria. The resulting Eimeria infection induced fecal oocyst shedding and intestinal lesions. Broilers fed 0.8% SID M+C (main effects, P ≤ 0.05) had decreased feed-to-gain ratio, increased duodenum and cecum luminal anti-Eimeria IgA titers, and decreased fecal oocyst counts, when compared to 0.6% SID M+C. The supplementation of anti-IL-10 (main effects, P ≤ 0.05) increased cecum luminal total IgA concentration and decreased cecum lesions. Interactions (P ≤ 0.05) were detected for growth performance and cecum luminal IFN-γ. Briefly, the highest body weight gain and feed intake were reached in PBS-gavaged broilers fed 0.8% SID M+C with no anti-IL-10 and in Eimeria-challenged broilers fed 0.8% SID M+C with anti-IL-10. In Eimeria-infected broilers, anti-IL-10 increased intestinal luminal IFN-γ and body weight gain only at 0.8% SID M+C. Collectively, anti-IL-10 increased intestinal luminal IFN-γ levels, decreased cecum lesions and restored growth only when fed with adequate amounts of sulfur amino acids. Our findings underscore the importance of providing sufficient essential nutrients to support the anti-IL-10 induced immunity against coccidiosis.

Effect of anti-fibroblast growth factor receptor 1 antibodies on phosphorus metabolism in laying hens and their progeny chicks

Targeting fibroblast growth factor 23 (FGF-23) signaling pathway is of interest in controlling body phosphate metabolism. This study investigated the effect of anti-fibroblast growth factor receptor 1 (FGFR1, major FGF-23 receptor in the kidney) antibodies on phosphate metabolism. White Leghorn laying hens (65-wk-old) were vaccinated with either a FGFR1 peptide vaccine (five 8-amino-acid peptides were selected, CrZ-1:LPEDPRWE, CrZ-2:LDKDKPNR, CrZ-3:RRPPGMEY, CrZ-4:GSPYPGVP, and CrZ-5:RMDKPSNC) or adjuvant control. At peak antibody titer, hens were artificially inseminated. Chicks from control-vaccinated hens were fed either a non-phytate phosphorus (nPP) sufficient (nPP = 0.45%, positive control) or deficient (nPP = 0.20%, negative control) diet, while chicks from each of the FGFR1 peptide vaccinated hens were fed with the above nPP-deficient diet, for 14 D. When compared to control hens, plasma phosphate in CrZ-1, CrZ-2, CrZ-3, CrZ-4, and CrZ-5 vaccinated hens were decreased by 33, 30, 24, 20, and 26%, respectively (P < 0.05); egg weight in CrZ-2 and CrZ-5 vaccinated hens were increased by 6 and 7%, respectively (P < 0.05); egg production in CrZ-3, CrZ-4, and CrZ-5 vaccinated hens tended to decrease (P = 0.085; decreased by 14, 15, and 13%, respectively). When compared to positive control, chicks from all other groups had decreased body weight gain (BWG) and feed intake (FI) during 1 to 14 D, and had decreased plasma phosphate, tibiotarsus ash, and 24-h phosphorus excretion on day 14. When compared to negative control, BWG of CrZ-1, CrZ-2, CrZ-3, and CrZ-4 antibody chicks were decreased by 23, 28, 26, and 20%, respectively (P < 0.05); FI of CrZ-1, CrZ-2, and CrZ-3 antibody chicks were decreased by 15, 15, and 18%, respectively (P < 0.05); plasma phosphate of CrZ-5 antibody chicks were decreased by 26% (P < 0.05); plasma FGF-23 levels of CrZ-4 antibody chicks were increased by 18% (P < 0.05); tibiotarsus ash content of CrZ-2, CrZ-3, and CrZ-4 antibody chicks were decreased by 20, 20, and 21%, respectively (P < 0.05). In conclusion, anti-FGFR1 peptide antibodies decreased egg production of hens and growth performance of their progeny chicks probably by activating FGF-23 signaling and stimulating FGF-23 production.

Egg yolk antibodies (IgY) and their applications in human and veterinary health: A review

Egg yolk constitutes a relevant alternative source of antibodies. It presents some advantages over mammalian serum immunoglobulins regarding productivity, animal welfare and specificity. The main immunoglobulin present in avian blood (IgY) is transmitted to their offspring and accumulates in egg yolks, which enables the non-invasive harvesting of high amounts of antibodies. Moreover, due to structural differences and phylogenetic distance, IgY is more suitable for diagnostic purposes than mammalian antibodies, since it does not react with certain components of the human immune system and displays greater avidity for mammalian conserved proteins. IgY has been extensively used in health researches, as both therapeutic and diagnostic tool. This article aims to review its applications in both human and veterinary health.

Vaccine to fibroblast growth factor 23 peptides increases eggshell strength

Strategies that would increase eggshell quality could be of considerable value to egg producers. This research demonstrated the effective use of fibroblast growth factor 23 (FGF-23) peptide vaccines to increase eggshell quality of Single Comb White Leghorn laying hens (from 69 to 72 wk of age). Hens, fed a standard diet (containing 900 IU/kg vitamin D3), 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. Laying hens vaccinated with either FGF-23 peptide NP1 or NP7 had increased (P < 0.05) plasma phosphate level (mmol/L; NP1 = 1.74, NP7 = 1.76, control = 1.47), egg specific gravity (NP1 = 1.083, NP7 = 1.083, control = 1.079), and eggshell strength (g of force; NP1 = 4002, NP7 = 4157, control = 3102) when compared to control vaccinated hens. FGF-23 peptide NP1 vaccinated hens also had increased eggshell thickness (mm, P < 0.001), shell weight (g, P = 0.032), and shell index (% of whole egg, P = 0.023) when compared to control vaccinated hens. FGF-23 peptide NP7 vaccinated hens tended to have decreased eggshell weight (P = 0.064) when compared to control vaccinated hens. Hatchability of fertilized eggs was not affected in incubations 1 and 3, but tended to be decreased (P = 0.097) by FGF-23 peptide NP1 vaccination in incubation 2. In conclusion, vaccines to FGF-23 peptides increased eggshell quality of laying hens with minimal adverse effects on egg internal quality. The effect of FGF-23 peptide vaccination on hatchability remains to be clarified.

Additive effects of fibroblast growth factor 23 neutralization and dietary phytase on chick calcium and phosphorus metabolism

Phytase hydrolyzes phytate rendering phosphorus available for intestinal absorption, while systemic neutralization of fibroblast growth factor 23 (FGF-23), using anti-FGF-23 antibody, has been shown to increase phosphate retention. Hence, neutralization of FGF-23 should be additive with phytase in reducing dietary non-phytate phosphorus (nPP) needs in chickens fed plant-based diets rich in phytic acid. This study was designed to test the additive effects of maternally derived anti-FGF-23 antibody and dietary phytase on the performance of chicks fed a low nPP diet from one to 14 d. Single Comb White Leghorn laying hens were vaccinated with either an adjuvant control or a synthetic FGF-23 peptide (GMNPPPYS). Chicks from vaccinated hens with control or anti-FGF-23 maternal antibodies were fed either a diet containing 0.2% nPP and 0.9% calcium with or without 500 unit phytase per kg of diet (2 × 2 factorial with main effects of antibody type and phytase addition, n = 15 pens of chicks/treatment). A significant interaction between dietary phytase and maternally derived anti-FGF-23 antibody on growth and feed efficiency was observed (P ≤ 0.05), in which chicks receiving either phytase or maternally derived anti-FGF-23 antibody had improved body weight gain (21 or 15%, respectively) and feed efficiency (16 or 18%, respectively) as compared to chicks with control antibody and not fed phytase. Both phytase and maternally derived anti-FGF-23 antibody independently increased (P ≤ 0.05) plasma phosphate (11 and 11%, respectively) and percent tibiotarsus ash (13 and 11%, respectively). Significant main effects and the lack of an interaction supported an additive effect of phytase and anti-FGF-23 antibody on plasma phosphate and percent tibiotarsus ash. Feeding phytase to chicks fed 0.2% nPP increased plasma FGF-23 levels by 22% (P ≤ 0.05); however, no effects of anti-FGF-23 antibody on plasma FGF-23 levels were observed. In conclusion, dietary phytase and presence of anti-FGF-23 antibody have an additive effect on plasma phosphate and tibiotarsus ash in chicks fed low nPP diets. Data support that phytase and anti-FGF-23 antibody increase phosphate utilization by different mechanisms.

Maternally derived anti-fibroblast growth factor 23 antibody as new tool to reduce phosphorus requirement of chicks

Novel means to reduce phosphate input into poultry feeds and increase its retention would preserve world phosphate reserves and reduce environmental impact of poultry production. Here we show that a maternally derived antibody to a fibroblast growth factor-23 (FGF-23) peptide (GMNPPPYS) alleviated phosphorus deficiency in chicks fed low non-phytate phosphorus (nPP) diets. White Leghorn laying hens were vaccinated with either an adjuvant control or the synthetic FGF-23 peptide, and chicks with control or anti-FGF-23 maternal antibodies were fed a diet containing either 0.13 or 0.45% nPP (experiment 1), and 0.20 or 0.45% nPP (experiment 2) for 14 d. In both experiments, decreasing nPP from 0.45 to 0.13 or 0.20% decreased BW gain, G:F, excreta phosphorus, plasma phosphate, and plasma FGF-23 at all time periods examined (nPP main effect, P < 0.05). In experiment 1, chicks with maternal anti-FGF-23 antibody had increased tibiotarsi ash (d 14), and decreased excreta phosphate (d 7, 14) and plasma intact parathyroid hormone (d 7) when compared to chicks with control antibody (antibody main effect, P < 0.05). Mortality (d 7 to 14, 1 to 14), posture scores (d 7, 14) and bone lesion scores (d 14) decreased and plasma phosphate (d 14) increased in anti-FGF-23 chicks fed 0.13% nPP, compared to those with control antibody on the same diet (P < 0.05). In experiment 2, chicks with maternal anti-FGF-23 antibody had increased tibiotarsi ash (d 14), and plasma phosphate (d 14) and 1,25(OH)2D3 (d 14) levels, compared to chicks with control antibody (antibody main effect, P < 0.05). BW gain and G:F were increased in chicks with anti-FGF-23 antibody fed 0.20% nPP, compared to control antibody chicks on the same diet, at all time periods examined (P < 0.05). In conclusion, maternally-derived anti-FGF-23 antibody increased phosphorus retention in chicks fed diets containing either 0.13 or 0.20% nPP and thereby, reduced signs of phosphorus deficiency.