Lymphoid Organ Weights Research Articles

The comparative effects of probiotics on growth, antioxidant indices and intestinal histomorphology of broilers under heat stress condition.

Heat stress adversely affects both the productivity and well-being of chickens. Probiotics offer beneficial impacts on the health and growth performance of broilers. The current study investigates the influence of administering of Bacillus (including B. subtilis, B. licheniformis, B. coagulans, and B. indicus) and Lactobacillus (consisting of L. acidophilus, L. plantarum, L. buchneri, and L. rhamnosus) probiotics via drinking water, either singular or combined, on various aspects including growth performance, oxidative stress markers, carcass characteristics, fecal microbial composition, intestinal structure, and intestinal pH in broilers exposed to chronic heat stress. A total of 150 one-day-old broiler chicks were divided into 5 groups: (1) NC, negative control; (2) HS, birds exposed to chronic heat stress; (3) HSpBacil, exposed to chronic heat stress and received Bacillus probiotic; (4) HSpLAB, subjected to chronic heat stress and provided with Lactobacillus probiotic; (5) HSpMix, subjected to chronic heat stress and administered a combined probiotic from Bacillus and Lactobacillus. The HS group exhibited significantly reduced levels of growth performance, carcass traits, and notably affected oxidative stress indices, as well as intestinal pH and histomorphology in the birds. Additionally, the administered probiotics led to increased weight of lymphoid organs, enhanced body weight gain, and improved intestinal histomorphology. Furthermore, the probiotics decreased malondialdehyde and increased total antioxidant capacity in broilers. In conclusion, Bacillus and Lactobacillus probiotics, as single or multi-species, particularly Lactobacillus and combined probiotic, demonstrated potential in alleviating the adverse effects of heat stress in broiler chickens. They could serve as beneficial feed additives and growth enhancers.

Early-life immunomodulation by carvacrol delivered in ovo in broiler chickens

In the first 2 wk after hatching, broiler chickens are vulnerable to enteric pathogens due to underdeveloped gastrointestinal and immune systems. Carvacrol has been reported to improve digestive and immune functions. This study aimed to optimize immune development of broiler chickens by delivering carvacrol in ovo. Effects of 2 in ovo treatments delivered at embryonic day (E)17.5 (saline or carvacrol) were evaluated at 3 stages (E19.5, hatch, and d 14 posthatch). Hatchability, performance parameters, lymphoid organ and yolk sac weights were determined. Histomorphology assessment was performed for jejunal samples at hatch and bursa of Fabricius samples at hatch and d 14. Gene expression of immune-relevant genes was determined for jejunal, bursal, and yolk sac samples over time. At hatch, BW was 0.85% lower (P = 0.02) after in ovo carvacrol delivery compared to the controls. Interactions between in ovo treatment and age were found for gene expression. At hatch, carvacrol treatment resulted in lower expression of proinflammatory cytokines IL-8 and IFN-γ in the yolk sac compared to the controls (P = 0.05 and < .001, respectively) suggesting a potential role for carvacrol-mediated immune modulation. At d 14, carvacrol treatment led to lower expression of proinflammatory cytokine IL-6 in the bursa compared to the controls (P = 0.002). In ovo carvacrol delivery led to bursal histomorphometric changes, including a larger cortex in the bursal follicles (P = 0.03), and a higher cortex/medulla ratio (P = 0.04) compared to the controls, indicating increased B-cell stimulation and maturation. Main effects were found for carvacrol treatment in the jejunum, with overall higher expression of proinflammatory mediators IL-1β and NF-κB, and anti-inflammatory IL-10 compared to the controls (P = 0.04, 0.02, and 0.02 respectively) from E19.5 to d 14. Age-related main effects showed various alterations in expression dynamics of immune-related genes across all tissues over time. Our findings suggest changes in immune parameters occur as the chicken develops, but these mostly do not interact with in ovo carvacrol treatment. In ovo carvacrol treatment alters immune activity of broiler chickens independent of age.

Effect of feeding chitosan and blend of essential organic acids on growth performance, haematological parameters and innate immunity in early aged male layer chicks.

The use of antibiotics as conventional feed additives in poultry operations have proven useful, however resulted serious health concerns to consumer due to their bio-accumulation, besides rising problem of antimicrobial resistance in microbes, thus, an alternative to antibiotic growth promoter have called for. One of the aim of the experiment was to assess the lone and combined effects of feeding of chitosan oligosaccharide (COS) and blend of organic acids and short chain fatty acids in essential oils on growth performance, haematological parameters, relative lymphoid organ weight and innate immunity in early aged layer chick(male birds). A total of ninety, day-old chicks were randomly allotted into five groups: CO, Control group fed only poultry feed ; AGP, antibiotic growth promoter fed Avilomycin at the dose of 200mg/kg of poultry feed; CH, chitosan oligosaccharide fed at the rate of 100mg/kg feed; OE, blend of organic acids and short chain fatty acids in essential oils contained 1000 to 2000mg/kg feed in a graded dose per week and CH + OE, chitosan oligosaccharide plus blend of organic acids and short chain fatty acids in essential oils at consistent rate and manner as followed for each of given feed additives when fed individually. Data on growth performance, samples for haematological parameters and innate immunity were measured and assayed on 7th, 21st and 42nd day post feeding (dpf) respectively. The results showed that compared with the control group; there is a marginal gain in body weight at 7th and 21st dpf in CH group and the corresponding CH + OE group. Feed conversion ratio in CH group was remarkably good at 7th and 21st dpf. No significant difference was observed in relative organ weights of thymus, spleen and Bursa of Fabricius in treatment groups as compared to control birds; however a significant rise in splenic weight index in OE fed birds at 42nd dpf noted. Haematological changes were inconsequential in treatment groups with an exception to enhancement of heterophil to lymphocyte ratio (H:L ratio) in CH group at 42nd dpf. Serum lysozyme activity proportionately elevated in CH + OE group on 21st and 42nd dpf when measured against control group; on the other hand no detectable augmentation of gut lysozyme activity observed. Both serum bactericidal and gut bactericidal activity boosted in combinatorial group at 42nd dpf. These results indicated that early age feeding of chitosan individually or combination with organic acids and short chain fatty acids in layer chick is beneficial, as it has the potential to enhance body weight gain to some extent and improves systemic and localized innate immunity to offer protection against infectious assaults thus may avoid early chick mortality in farms.

INVESTIGATING THE POTENTIAL OF SILYMARIN AND/OR SPIRULINA PLATENSIS TO ATTENUATE THE DELETERIOUS CONSEQUENCES OF AFLATOXIN CONTAMINATION IN BROILERS’ FEEDS

The aim of this investigation was to establish the impact of silymarin and/or Spirulina platensis in mitigating the adverse effects of aflatoxin (AF) present in poultry feed. A total of 450 one-day-old, unsexed Ross 308 broiler chicks were allocated to a completely randomized design with five experimental groups. Each group consisted of six replicate, housing 15 chicks per replicate. The treatment groups comprised: 1) the negative control (NC) fed the standard diet lacking AF supplementation; 2) the positive control (PC) fed the standard diet contaminated with 1 mg AF/kg; 3) the silymarin (SIL) fed the PC diet + 0.6 g silymarin/kg feed; 4) the Spirulina platensis (SP) fed the PC diet + 1g /kg diet; 5) the silymarin +Spirulina fed the PC diet + 0.6 g SIL/kg + 1g SP/kg diet. Productive performance, serum biochemical profile (levels of AST, ALT, total cholesterol, HDL, uric acid, creatinine, and calcium), weight of lymphoid organs, levels of glutathione and malonaldehyde in the liver, antibody titers against NDV and IBD, concentration of cecal bacteria, nutrition composition of flesh, and level of remnants of AF in liver and flesh were studied. Our findings revealed a successful reversal of adverse effects caused by AF. Supplementation with either SIL and/or SP restored performance metrics to the levels observed in the non-contaminated (NC) fed control group. These results indicate that dietary inclusion of 0.6 g of SIL/kg and/or 1 g of SP/kg represents a suitable strategy to maintain broiler growth performance, immune function, serum composition, and meat quality in birds exposed to AF contamination at a concentration of 1 mg/kg of feed. Keywords: aflatoxicosis, silymarin, Spirulina platensis, poultry, productive performance

Comparative effects of dietary zinc nanoparticle and conventional zinc supplementation on broiler chickens: A meta-analysis.

Zinc (Zn) is important for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. The gastrointestinal absorption of Zn in broiler chickens was notably low. One approach that has been explored for enhancing the bioavailability of Zn is the development of Zn nanoparticles (NPs). Zn is required for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. Therefore, this study aimed to assess the impact of conventional Zn and Zn NPs on broiler chickens using a meta-analysis methodology. A database was built from published literature to evaluate the effects of the addition of Zn NPs and conventional Zn on broiler chicken responses, including the following parameters: production performance; carcass cuts; visceral organ weight; lymphoid organ weight; nutrient digestibility; intestinal villi; mineral Zn, calcium, and phosphorus concentrations; hematology; blood parameters; immunoglobulin; and intestinal bacterial population. Various scientific platforms, including Scopus, Web of Science, PubMed Central, and Google Scholar, were used to search for peer-reviewed articles. A database was created from 25 studies that met the inclusion criteria. The data were then processed for a meta-analysis using a mixed-model methodology. Different types of Zn (NPs versus conventional) were considered fixed effects, different studies were treated as random effects, and p-values were used as model statistics. Across the parameters observed in this study, the use of Zn NPs was more efficient in Zn utilization than conventional Zn, as evidenced by the average dose of Zn NPs being much lower than that of conventional Zn (79.44 vs. 242.76 mg/kg) yet providing similar (p > 0.05) or even significantly better effects (p < 0.05) compared to conventional Zn usage. This investigation revealed the beneficial influence of Zn NPs in broiler chickens compared to the conventional utilization of Zn through an all-encompassing meta-analysis. Moreover, Zn NPs have proven to be more effective in Zn utilization when juxtaposed with conventional Zn, as demonstrated by the significantly lower quantity of Zn NPs administered compared to conventional Zn, while yielding comparable or even superior outcomes compared to the traditional utilization of Zn. A limitation of this study is that the Zn NPs used were sourced from inorganic Zn NPs. Therefore, future research should focus on evaluating the efficiency of organic Zn NPs in broiler chicken feed.

Significance of successive feeding of sources of n-3 fatty acids to broiler breeders and their progeny on growth performance, intestinal lesion scores, lymphoid organs weight and plasma immunoglobulin A in broiler chickens challenged with Eimeria

The study examined the effects of successive feeding of sources of n-3 PUFA to broiler breeders (BB) and their progeny in broiler chickens challenged with Eimeria. The BB were fed: 1) control (CON), corn-soybean meal diet, 2) CON + 1 % microalgae (DMA), as a source of DHA and 3) CON + 2.50% co-extruded full fat flaxseed (FFF), as a source of ALA. Eggs were hatched at 34, 44, and 54 wk of age. Posthatch treatments (BB-progeny) were: CON-CON, DMA-CON, FFF-CON, DMA-DMA and FFF-FFF with diets formulated for starter (d 1-10) and grower/finisher (d 11-42) phases. All chicks were orally challenged with Eimeria (E. acervulina and E. maxima) on d 10. Relative to CON, DMA and FFF increased concentration of n-3 PUFA by ≥ 2-fold in hatching eggs and progeny diets. There were no (P > 0.05) interactions between treatment and BB age on d 0 to 10 growth. In general, BB age affected (P < 0.05) growth performance throughout the study. In the starter phase, successive exposure to DHA and ALA improved FCR over CON-CON (P < 0.01). The interaction between treatment and BB age in grower/finisher was such that DHA exposure to younger BB resulted in poor growth performance (P < 0.05) relative to exposure to older BB. In contrast, exposure to ALA had similar (P > 0.05) growth performance irrespective of BB age. Moreover, successive exposure to ALA resulted in higher BWG, breast weight and lower FCR compared to successive exposure to DHA (P < 0.05). There were no (P > 0.05) interactions between treatment and BB age on the intestinal lesion scores, lymphoid organ weights and concentration of plasma immunoglobulin A (IgA). Successive exposure to DHA resulted in higher (P = 0.006) jejunal lesion scores than CON-CON birds. The results showed that successive exposure of DHA and ALA improved FCR relative to non-exposed birds in the starter phase. However, responses in the grower/finisher phase depended on n-3 PUFA type, with birds on successive ALA exposure supporting better growth and breast yield than birds on successive DHA exposure.

Effect of citrus peeling (Citrus sinensis) on production performance, humoral immunity, nutrients, and energy utilization of broiler quails

Citrus citrus peeling has a wide range of vitamins and trace minerals that have antioxidant and antimicrobial properties. It is hypothesized that the addition of citrus peeling to broiler quail diets can improve their production performance, humoral immunity, nutrients, and energy utilization. A trial was performed to study the impact of a methanolic extract of citrus peeling (Citrus sinensis) on production performance, humoral immunity, nutrients, and energy utilization of broiler quails. A healthy day-old 300 quails were randomly assigned with 5 replicates each replicate had 15 birds and used CRD for the trial. Different dietary supplementations were presented to different groups. The control group was not supplemented with any supplementation in their feed. While, the 3 other groups were supplemented by 0.5 mL/kg, 1 mL/kg, and 1.5 mL/kg of methanolic extract of dried Citrus sinensis peel (DCSP) in the basal diet (DCSP0.5, DCSP1, and DCSP1.5 groups, respectively). All the birds were allowed ad libitum feeding and water. The feed intake and FCR were significantly higher in the control group, followed by DCSP0.5, and then DCSP1. The significantly lowest feed intake and FCR were observed in the DCSP1.5 group. The weight gain and dressing % were significantly improved with the increasing level of methanolic extract of Citrus sinensis. The significantly highest weights of thymus, spleen, and bursa were recorded in the DCSP1.5 group, followed by the DCSP1. The antibody titers against infectious bursal disease, New Castle disease, and infectious bronchitis disease were significantly higher in the DCSP1.5, DCSP1, and DCSP0.5 groups than in the control group. It was concluded from the study that supplementation of quails with methanolic extract of citrus at a dose rate of 0.5 to 1.5 mL/kg of feed can improve feed intake, weight gain, FCR, dressing percentage, relative weight of lymphoid organs, and digestibility coefficient. Supplementation of Citrus sinensis has also concluded positive impacts on antibody titers against various viral diseases. The best improvement in the evaluated parameters was observed at a dose of extract of citrus was 1.5 mL/kg of feed.

Efficacy of clove and tulsi supplementation in drinking water in broiler immunity.

Medicinal plants or their products are popular substitutes for antibiotics or other synthetic growth promoters for their beneficial effects and cost-effectiveness. Clove (Cv) and tulsi (Ts) are rich in phytochemicals and are used to augment the growth performance of poultry. The current investigation was carried out to evaluate the effects of Cv and Ts supplementation in drinking water on the morphologic and morphometric adaptations in the lymphoid organs. The experiment was conducted on 60 broiler chicks, divided into 4 homogenous groups (5 pens/group and 3 broilers/pen) named T0 (control), T1 (0.5% Cv and 2% Ts), T2 (1% Cv and 3% Ts) and T3 (1.5% Cv and 4% Ts). The treatments were administered from days 8 to 28. Lymphoid organs (thymus, spleen and bursa of Fabricius) were collected on days 14, 21 and 28 after sacrificing five broilers from each group. The treatment groups had higher thymus and spleen weights on day 21, whereas the weights of the bursa of Fabricius were higher on days 14, 21 and 28. In the histomorphologic study, no noticeable difference in the histoarchitectures of the lymphoid organs was noticed. However, substantial differences in the cortico-medullary ratio and the number of follicles in the thymus and bursa of Fabricius, respectively, were found in the histomorphometric investigation. The inclusion of Cv and Ts in drinking water augments the weight of lymphoid organs with histomorphometric adaptations that might improve the immune status in broilers.

Impact of Cassava Leaf Meal as a Rice Bran Substitute and Enzyme Supplementation on Lymphoid Organ Weight and Digestibility in Broiler Chickens

Cassava leaves are a potential alternative feed ingredient due to their high levels of crude protein and energy. However, their utilization in poultry feed is constrained by factors such as cyanic acid, fiber content, and nutrient digestibility. This study aimed to investigate the impact of including cassava leaf meal (CLM) as a rice bran substitute and enzyme supplementation on lymphoid organ development and metabolizable energy parameters in broiler chickens. A 2x3 completely randomized factorial design was conducted using 48 Cobb-strain broilers unsexing at 35 days old. The treatments included different levels of CLM and enzyme (NSP and protease) supplementation at a dose of 250 g/ton of feed. The treatments consisted of R0E0: 0% CLM without enzyme, R0E1: 0% CLM with enzyme, R1E0: 1.5% CLM without enzyme, R1E1: 1.5% CLM with enzyme, R2E0: 3% CLM without enzyme, and R2E1: 3% CLM with enzyme. The variables assessed were lymphoid organ development (thymus, bursa Fabricius, and spleen) and metabolizable energy parameters (Apparent Metabolizable Energy (AME), True Metabolizable Energy (TME), Apparent Metabolizable Energy Corrected to Nitrogen (AMEn), and True Metabolizable Energy Corrected to Nitrogen (TMEn)). The data were subjected to analysis of variance (ANOVA) with post-hoc tests conducted for significant differences. Results indicated no interaction between CLM and enzymes in lymphoid organ development and energy metabolizable. The inclusion of CLM led to a reduction in AME and TME (p&amp;lt;0.05). However, enzyme supplementation significantly increased the relative weight of lymphoid organs (thymus, bursa Fabricius, spleen) and metabolizable energy parameters (AME, TME, AMEn, and TMEn) (p&amp;lt;0.05). Importantly, the inclusion of CLM up to a level of 3.0% did not negatively impact the health of broiler chickens. Furthermore, the addition of enzymes effectively mitigated the negative effects associated with CLM inclusion in the feed, suggesting their potential as a strategy to improve feed utilization in broiler production systems.

Growth and response to Escherichia coli lipopolysaccharide challenge in Lohmann LSL-Lite pullets when fed a source of omega-3 fatty acids and yeast bioactives from hatch through to 16 wk of age

Growth and response to Escherichia coli lipopolysaccharide (LPS) challenge in Lohmann LSL-Lite pullets when fed a source of omega-3 fatty acids (n-3 FA) and yeast bioactives (YB) from hatch through to 16 wk of age (woa) were investigated. Co-extruded full fat flaxseed and pulse mixture (FFF; 1:1 wt/wt) supplied n-3 FA and YB were yeast cell walls processed with β-1,3-glucan hydrolase. A total of 1,064-day-old pullets were placed in cages (19 birds/cage) and allocated to 7 diets (n=8). The iso-caloric and iso-nitrogenous diets were control, control+1, 3, or 5% FFF and+0.025, 0.05, or 0.1% YB. The birds had ad libitum access to feed and water. Body weight (BW), feed intake, and lymphoid organs weight were recorded. At 15 woa, 2 pairs of pullets/cage received intravenous injection of either 1 mL of sterile saline without or with 8 mg LPS/kg BW. Injected pullets were bled, monitored for BW and cloaca temperature at time points within 168 h. Birds fed 1% FFF were heavier (P < 0.04) than birds fed other diets at 16 woa with FFF and YB exhibiting non-linear responses. Control birds had heavier (P=0.02) thymus at 4 woa. Spleen weight increased quadratically (P < 0.05) in response to FFF at 8 and YB at 16 woa. The LPS increased cloaca temperature and altered concentration of several plasma metabolites (P < 0.05). Theinteraction (P < 0.05) between LPS and diet was such thatcontrol birds exhibited lower creatine kinase (CK) upon challenge with LPS relative to birds fed other diets. The LPS birds fed 1% FFF and 0.05% YB showed higher plasmaalbumin than non-LPS cohorts. Non-LPS birds fedcontrol, 1 and 3% FFF had higher plasma K than LPS cohorts. In general, FFF and YB exhibited linear and quadratic effects (P < 0.05) onselect plasma metabolites. In conclusion, dietary provision of n-3 FA and YB influenced pullet BW at sexual maturity, development of lymphoid organs and modulated some plasma metabolites in response to LPS.

Effect of two brooding systems and four stocking densities on immune response and stress indicators of broiler chicks during the brooding period

This experiment investigated the effects of the brooding system (BS) and stocking density (SD) on the immune response of 1-14-day-old broiler chicks. A 3672 one-day-old Cobb 500 chicks were raised in two BSs (conventional floor brooding system (CFBS) and the newly developed multi-tier closed brooding system (NDBS)) at four different SDs (30, 60, 90, and 120 chicks/m2), resulting in a 2 × 4 factorial arrangement. Immunity data on lymphoid organ weights, maternal antibody titres to IBV, IBDV, and NDV, and stress indicators were collected on days 6 and 12. The results showed that CFBS and NDBS had similar effects on the relative development of chick lymphoid organs (Bursa, spleen, and thymus), the durability of the maternal humoral immune response against IBDV, and the maintenance of normal levels of stress indicators. Birds in CFBS outperformed NDBS in terms of the durability of maternal immunity to IBV and NDV. Birds in NDBS had a higher liver weight percentage than CFBS. Maternal immunity, lymphoid organ weights %, glucose and cholesterol concentrations were not altered by SD. In contrast to relative weights, differences in absolute lymphoid weights (g) were attributed to differences in live weights. An increase in SD per area unit resulted in an increase in heterophils and a decrease in lymphocyte percentage resulted in an increase in the ratio of heterophils to lymphocytes(H:L). In conclusion, birds in the higher SD had lower live weights and higher H:L ratios. Smarter brooding systems are needed to usher in a new era for the poultry industry. Highlights The brooding system and/or stocking density accounted for the stress factors of the birds. Both brooding systems increased the relative development of chick lymphoid organs and the durability of the maternal humoral immune response to IBDV. Smarter brooding systems are needed to apply the critical control point standard and usher in a new era for the poultry industry. As stocking density per unit area increased, live and liver weights decreased, and the lymphocyte ratio increased.

Comparative Biological Pathotyping of Newcastle Disease Virus Sub-genotypes VIIg, VIIh, and VIIi in Specific Pathogen Free (SPF) Chickens

Newcastle Disease (ND) is an infectious viral disease in poultry caused by the Newcastle Disease virus (NDV). The NDV that causes ND cases in Indonesia is genotype VII with various sub-genotypes. This study was conducted to compare the in vivo pathogenicity of ND virus sub-genotypes VIIg, VIIh, and VIIi in specific pathogen free (SPF) chickens. The virus isolates were isolated and identified as ND virus sub-genotypes VIIg, VIIh, and VIIi. The level of pathogenicity is known by calculating the mean death time (MDT) and the intravenous pathogenicity index (IVPI). The comparations of lesions of NDV were analyzed descriptively and statistically based on clinical signs, the ratio of lymphoid organ weight, and lesions in hematoxylin-eosin (HE). Isolate confirmation was conducted by harvesting the lung organs. ND was detected using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using specific primers of the fusion (F) fragment gene. The sequence was compared with that of other NDVs from GenBank and Analyzed using MEGA-6 software. The analysis results showed that the VIIh and VIIi sub-genotypes were virulent strains due to the MDT <60 hours with IVPI value index of 3.0, the lymphoid organs showing atrophy and lymphocyte depletion. On the other hand, the VIIg sub-genotype was a less virulent strain because it had an IVPI index of 0.0 with MDT >60 hours, and the lymphoid organs showed mild lymphocyte depletion. Based on the in vivo results with the sequence analysis at the cleavage site showed that ND isolates Sub-genotypes VIIh (112RRQRRF117) and GVIIi (112RRQKRF117) were virulent strains, but Sub-genotype VIIg (112GRQGRL117) was less virulent.

Effects of dietary zinc oxide nanoparticles supplementation on broiler growth performance, zinc retention, liver health status, and gastrointestinal microbial load

BackgroundZinc (Zn) is an essential trace element for poultry health and biological functions. Inorganic Zn, like Zn oxide and Zn sulfate, was commonly used in poultry feed due to its low cost. However, the bioavailability of inorganic Zn is low, leading to a high level of Zn being added to the feed and resulting in other issues. Zinc oxide nanoparticles (ZnO NPs) have emerged as a promising alternative to their bulkier counterparts, but concerns about their safety persist. Therefore, this study aimed to evaluate the potential benefits and toxicity of dietary ZnO NPs as a feed supplement and antibacterial agent in broiler chickens. Methods180 broiler chicks (Cobb500) were randomly allocated to five dietary treatment groups (36 birds/group). The experimental treatment groups were as follows: (G1) basal diet supplemented with 100 mg kg−1 ZnO (control group), (G2-G5) basal diet supplemented with 10, 40, 70, and 100 mg kg−1 ZnO NPs. The effects of dietary ZnO NPs at different inclusion levels were studied by measuring growth performance (FI, BWG, and FCR), Zn retention, liver enzyme activity, lymphoid organ weight, and gastrointestinal microbial load. ResultsThe results showed that dietary ZnO and different levels of ZnO NPs inclusion had no effect on broiler growth performance (p > 0.05). The birds fed dietary ZnO NPs retained significantly more Zn than the control group (p < 0.05), lowering feces Zn excretion. The supplementation of ZnO NPs did not reduce lymphoid organs weight; in fact, a notable increase in weight was observed in groups supplemented with higher levels of ZnO NPs when compared to the control group. Furthermore, no significant increase in liver weight (p > 0.05) or enzymatic activities (AST and ALT) were observed in birds fed ZnO NPs, indicating no liver damage occurred. ZnO NPs at 100 mg kg−1 in the diet showed antibacterial effects, reducing Enterococcus spp. and E. coli count significantly, without affecting commensal bacteria (lactic acid bacteria) count. ConclusionThe inclusion of ZnO NPs to broiler chicken feed as a Zn source had no negative effects on growth or health. Additionally, it increased Zn absorption and bioavailability, reduced Zn excretion, and exhibited potential antibacterial activity against tested pathogens.

Impact of stocking density and dietary nano-zinc supplementation on stress indicators, immunity, and DNA damage in broiler chickens

Effects of stocking density (SD) and nano zinc on oxidative status, immune function, and DNA damage in broilers were examined in the current study. Totally 480 one-day-old male broilers (Ross 308) were randomly divided into 4 treatments each contained 8 replicates. A 2 ´ 2 factorial arrangement with two groups for dietary zinc (Zn) form (inorganic or nano) and two groups for SD (low = 12 birds/m2 and high = 18 birds/m2) was conducted. Basal diets based on the corn-soybean meal were formulated. Relative liver weight was lower (P&lt;0.05) in broiler subjected high stocking density (HSD) but other lymphoid organ weights did not affect. Relative lymphoid organ weights were not affected by dietary nano zinc. HSD increased the serum corticosterone level of broiler (P&lt;0.05) but did not affect the blood heterophil:lymphocyte ratio, serum glutathione, superoxide dismutase, and malondialdehyde levels. Dietary nano zinc had no effect on these stress indicators. Serum interferon-gamma, interleukin 12, and interleukin 18 levels were not affected by HSD. Dietary nano zinc tended to reduce the interferon-gamma level (P=0.05) but did not affect interleukin 12, and interleukin 18 levels in broiler. Eeither HSD or nano zinc had no effect on DNA damage in lymphocyte. In conclusion, HSD may decrease the relative lymphoid organ weights and increase the stress indicators but did not affect the immunity and DNA damage. Generally, dietary nano zinc had no effect on stress indicators, immunity, and DNA damage in broiler.

Effect of dietary dexamethasone on the morphologic and morphometric adaptations in the lymphoid organs and mortality rate in broilers.

Thymus, bursa of Fabricius and spleen are the major lymphoid organs of avian species that plays a crucial role in their immunity. Though glucocorticoids are reportedly used as growth promoters, they also suppress the immune system. The objective of this study was to investigate the morphologic and morphometric adaptations in the lymphoid organs as well as the mortality rate in broilers in response to long-term treatment with dexamethasone (DEX). A total of 80 one-day-old broiler chicks (Cobb 500) were randomly divided into four homogenous groups (control - C and treatment groups - T1, T2, and T3). The treatment groups received DEX at the rate of 3, 5, and 7 mg/kg commercial feed. Samples, i.e. thymus, bursa of Fabricius, and spleen, were collected on 7, 14, 21, and 28 days of the experiment. Relative weight of the organs was calculated on each sampling day. The tissues were then processed and stained with haematoxylin and eosin stain for morphological and morphometric study. The relative weight of lymphoid organs was found substantially (p < 0.05) less in the DEX-treated groups. Significant (p < 0.05) reduction in lobular size and the cortical-medullary ratio was observed in the thymus of the DEX-treated broilers. Follicular atrophy and massive depletion of lymphocytes were evident in the bursa of Fabricius. The mortality rate was also increased which was largely dependent on the dose and duration of DEX treatment. The study results indicate that DEX treatment can alter the morphology and morphometry of lymphoid organs which might result in severe immunosuppression and increased mortality rate in broilers.

Impact of Prebiotic Supplementation on Productive Performance, Carcass Traits, and Physiological Parameters of Broiler Chickens under High Stocking Density Condition

The present study was performed to investigate the effect of increasing stocking density, prebiotic supplementation, and the interactions on broiler chicken performance and some physiological parameters. A total of 912 one-day-old chickens were used in this study, and they were randomly divided into six groups with 4 replicates each. The experiment included three levels of stocking densities (10, 13, and 15 broiler chicken/m2) in 6 groups. Groups 1, 3, and 5 were maintained without prebiotic supplementation, while groups 2, 4, and 6 received a diet supplemented with prebiotics in water (1cm/liter). Reducing stocking densities and adding prebiotics improved body weight, feed consumption, feed conversion ratio, hemoglobin, packed cell volume, oxidative stress parameters (total antioxidant capacity), and European production efficiency factor, while decreasing malondialdehyde levels. On the other hand, stocking density and prebiotic supplementation did not affect dressing percentage, the relative weight of giblet parts, hind part, front part, and lymphoid organs (thymus and bursa of Fabricius). In conclusion, adding prebiotics at 1 cm/liter (Mannan-oligo saccharide and B-Glucan) can partially mitigate the negative effects of high stocking density on production performance, physiological and oxidative stress parameters, and European production efficiency factor. Keywords: Antioxidant biomarkers, Broiler chicken, β-glucan, Mannan oligosaccharide, Oxidant, Prebiotic, Stocking density

Modulation of Immunity, Antioxidant Status, Performance, Blood Hematology, and Intestinal Histomorphometry in Response to Dietary Inclusion of Origanum majorana in Domestic Pigeons’ Diet

This experiment was conducted to evaluate the effect of adding Origanum majorana (OM) powder to domestic pigeon diets on growth performance, feeding and drinking behaviour, blood hematology, blood biochemical parameters, blood inflammatory and oxidative markers, carcass characteristics, the weights of lymphoid organs, and and intestinal cecal, and bursa of Fabricius histology. A random distribution of fifty-four unsexed pigeon squabs (30 days old, average body weight; 321 g ± 7.5) into three groups was done. The first group was fed the grower basal diet without adding OM powder, while OM powder was added at levels of 0.5 and 1% to the basal diets of the second and third groups, respectively. The changes in growth performance parameters and feeding and drinking behavior under OM powder's effect were insignificant. However, the lymphoid organs (spleen and thymus) significantly increased in weight (p < 0.05) in the OM-fed groups. Moreover, blood examination showed positive responses to OM powder in terms of blood cell counts (RBCs andWBCs), and the values of hemoglobin, hematocrit, mean corpuscular volume, lymphocyte numbers, levels of globulin, and glutathione peroxidase enzyme were significantly increased. The numbers of heterophils, the ratio of heterophil to lymphocyte, malondialdehyde levels were reduced (p < 0.05). Histomorphometry examination revealed increases in intestinal villi height, cecal thickness, and bursal follicle area and number. These results indicated that adding OM powder to the pigeon diet may improve their immunity, increase their antioxidant status, and correct some hematological disorders.

Effect of clove buds powder supplementation on hematological profile, biochemical parameters, lymphoid organs, and cell-mediated immunity of broilers.

Phytogenic feed additives are products derived from plants used to improve the performance and health of animals. Nowadays, this type of phytogenic feed additive is widely used as an alternative to antibiotic growth promoters in poultry feed, and clove bud is one of the most effective medicinal herbs that has caught the attention of researchers. This experiment was conducted to evaluate the effects of adding clove bud powder to the broiler chicken's feed on the hematological profile, biochemical parameters, lymphoid organs, and cell-mediated immunity. A total of 360 unsexed chicks (Ross 308) were allotted to three groups. All chicks were raised under the same normal management conditions from 1 day to 6 weeks of age. The first group was fed a basal diet and the other two groups were assigned to add 0.5% and 1.0% of clove bud powder to the basal diet. The studied traits were total leukocyte counts (TLC), differential leukocyte counts (DLC), blood cholesterol level, blood liver enzymes [aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase (ALP) enzymes], the weight of lymphoid organs (bursa of Fabricius and spleen), and cell-mediated immunity. Despite the significant and varied changes (p ≤ 0.05) that resulted from adding clove buds powder to the broiler feed in the second and third weeks, the results at the end of the experiment indicated that there was no negative effect of adding clove powder on the TLC and DLC, as well as the heterophils/lymphocytes ratio. In addition, feeding on a diet containing clove buds powder had no significant effect on the level of cholesterol and liver enzymes in the blood, except for (ALP), which showed a significant increase (p ≤ 0.01) in comparison to the control group. Moreover, the results showed in the second and fifth weeks a significant increase (p ≤ 0.05) in the relative weight of the spleen, but, in general, there were no significant effects at the end of the experiment on the relative weight of the lymphoid organs. Furthermore, the broiler chickens that consumed clove bud powder at a rate of 0.5% showed a highly significant (p ≤ 0.01) cellular immune response. This study concluded that the addition of clove bud powder had no negative effect on leukocyte counts or differentiated leukocyte counts. The addition also raised the spleen weight and improved the level of blood alkane phosphatase activity and cellular immune response in broiler chickens during the growth stages.

Effect of humic acid and probiotics on immunity of broiler chickens.

The immune system in chickens has a fundamental role in controlling many diseases based on vaccination, thus enhancement of the immune system response is a priority. The aim of this experiment was to study the effect of probiotics and humic acid on immunity of broiler chickens. Day-old 300 Ross broiler chicks were segregated into 5 groups of 60 chicks per group. Group C was considered as a control. Groups T1, T2, T3, and T4 were given probiotics, antibiotics, humic acid for the first 7 days and humic acid for 42 days, respectively. Samples were collected on days 27 and 42 to assess the humoral immunity, cellular immunity, lymphoid organs weight, and differential leucocyte count (DLC). The results showed a significant increase (p < 0.05) in antibodies titer against Newcastle disease virus in chickens given humic acid (T4) daily for 42 days as compared to the control. There was also a significant increase in antibodies titer in the T1 group given probiotic for the first week lasting up to day 27 as compared to the control. The skin thickness of T4 group showed a significant increase as compared to T1 and T2 groups after 24 hours of DNCB challenge. After 48 hours, the thickness was still significantly higher in the T4 group as compared to other groups except for the control. There were no significant differences in Bursa of Fabricius/Body weight (%) between the groups. Spleen/Body weight (%) was significantly higher in the control group and T1 than the other groups on day 42. The DLC remains normal in all groups. It is concluded that the humic acid has a stimulant and strengthening effect on the humoral and cellular immune system when given daily to broiler chickens. Moreover, the use of humic acid and probiotics with good hygiene in the first week of age may alternate the use of antibiotics which could be toxic and raise bacterial resistance.

Internal relative potency factors based on immunotoxicity for the risk assessment of mixtures of per- and polyfluoroalkyl substances (PFAS) in human biomonitoring

Relative potency factors (RPFs) for per- and polyfluoroalkyl substances (PFAS) have previously been derived based on liver effects in rodents for the purpose of performing mixture risk assessment with primary input from biomonitoring studies. However, in 2020, EFSA established a tolerable weekly intake for four PFAS assuming equal toxic potency for immune suppressive effects in humans. In this study we explored the possibility of deriving RPFs for immune suppressive effects using available data in rodents and humans. Lymphoid organ weights, differential blood cell counts, and clinical chemistry from 28-day studies in male rats from the National Toxicology Program (NTP) were combined with modeled serum PFAS concentrations to derive internal RPFs by applying dose–response modelling. Identified functional studies used diverse protocols and were not suitable for derivation of RPFs but were used to support immunotoxicity of PFAS in a qualitative manner. Furthermore, a novel approach was used to estimate internal RPFs based on epidemiological data by dose–response curve fitting optimization, looking at serum antibody concentrations and key cell populations from the National Health and Nutrition Examination Survey (NHANES). Internal RPFs were successfully derived for PFAS based on rat thymus weight, spleen weight, and globulin concentration. The available dose–response information for blood cell counts did not show a significant trend. Immunotoxic potency in serum was determined in the order PFDA > PFNA > PFHxA > PFOS > PFBS > PFOA > PFHxS. The epidemiological data showed inverse associations for the sum of PFOA, PFNA, PFHxS, and PFOS with serum antibody concentrations to mumps and rubella, but the data did not allow for deduction of reliable internal RPF estimates. The internal RPFs for PFAS based on decreased rat lymphoid organ weights are similar to those previously established for increased rat liver weight, strengthening the confidence in the overall applicability of these RPFs.