The Effects of Dietary Spirulina platensisis on Physiological Responses of Broiler Chickens Exposed to Endotoxin Stress.

This study was proposed to highlight the impact of dietary Spirulina platensis (SP) supplementation in alleviating the deterioration effect of Escherichia coli (EC) on the growth performance, redox biomarkers, immune reaction, and hindgut microbial counts and acidosis in broiler chickens. Four hundred Cobb500, one-day-old, broiler chickens were deposited in battery cages (10 chicks per cage). The chicks were distributed into totally randomized 2 × 2 factorial treatments (10 replicate cages per treatment) from the day 22 to the day 42 of age. Birds of two of the groups were fed on a basal diet without SP supplementation (-SP groups), while birds of the other two groups were fed on a basal diet supplemented with 10 g/kg SP (+SP groups). At day 36th of age, birds in one of the -SP and +SP groups were challenged by an intraperitoneal (i.p.) injection with 107 CFU/bird EC (O157:H7 strain) in 0.5 mL sterilized saline (+EC groups), whereas the other non-challenged groups were i.p. injected with 0.5 mL saline only (-EC groups). The current study results indicated that the boilers challenged with EC had a significant (p < 0.05) lower performance, poor antioxidant activity, immunosuppression, and higher numbers of pathogenic bacteria in the intestine when compared with the non-challenged birds. Dietary SP inclusion enhanced (p < 0.05) broiler growth, antioxidant activity, immune response, and intestinal beneficial bacteria and acidosis. Moreover, SP alleviated the reduction in all these parameters after exposure to EC infection. Therefore, diets containing 10 g/kg SP could be used as a promising approach to maximize broilers' production and support their health, particularly when challenged with EC infection.

Effect of Dietary Blue-Green Microalgae Inclusion as a Replacement to Soybean Meal on Laying Hens' Performance, Egg Quality, Plasma Metabolites, and Hematology.

Spirulina platensisis (SP) is a blue-green microalgae with a high value for animal and poultry nutrition. The study employed 250 40-week-old, HY-Line W-36 commercial laying hens. The layers received one of five experimental diet substitutes in five groups for 10 consecutive weeks (five replicates of 10 hens each group); a soybean-corn basal diet formulation without SP (Control group) or the soybean partially substituted with 3% SP, 6% SP, 9% SP, and 12% SP (for the remaining four groups). The results showed that dietary SP treatment significantly (p < 0.05) improved the productive performance, egg quality, blood metabolites, and hematological parameters of laying hens. In addition, there were linear and quadratic effects for increasing the levels of SP inclusion into the layer diets; however, the highest values of most parameters were observed when using 9% SP (90 g/kg of the layer diets). Furthermore, the results showed that 4.7% of the soybean meal ingredient in the layer diet could be replaced by 1% of SP. In conclusion, the partial replacement of soybean meal by SP into layer diets could be used as a promising nutritional approach to optimize the performance of laying hens.

Modulation of Antioxidant Defense, Immune Response, and Growth Performance by Inclusion of Propolis and Bee Pollen into Broiler Diets.

(1) Background: Propolis and bee pollen have natural bioactive compounds that may support the performance and immunological response of broilers. (2) Methods: The study included 300 1 d old Cobb-500 broiler chicks. Starting from 22−42 d of age, chicks were divided according to a 2 × 2 factorial design into one of the four treatment groups (5 replicates × 15 chicks per replicate); a basal diet without supplementation (CONT) or supplemented with 1 g/kg of propolis (PR) or bee pollen (BP) separately or in an even combination (PR + BP). (3) Results: A significant (p < 0.05) increase was obtained in the body-weight gain of broilers treated with PR, BP, and PR + BP compared to the CONT. The total antioxidant capacity and superoxide dismutase were highly (p < 0.05) activated in all treated groups compared to the CONT. Immunological parameters, especially the leukocyte cell viability, T- and B-lymphocyte proliferation, immunoglobulins (IgA and IgM), antibody titers, and wattle-swelling test were significantly (p < 0.05) enhanced in the treated broilers with PR and/or BP compared to the CONT. (4) Conclusions: The dietary supplementation of PR and/or BP could be beneficial for broiler growth through maximizing the antioxidant- and immune-system defenses.

Intermittent Lighting Program Relieves the Deleterious Effect of Heat Stress on Growth, Stress Biomarkers, Physiological Status, and Immune Response of Broiler Chickens.

The effects of heat stress on broiler performance and immunological response were explored using lighting-program manipulation as a potential tool. The study included 200 Cobb500 broiler chicks that were one day old at the time of recruitment. The birds were divided into four-compartment groups with similar environments (five cages per compartment, ten chicks per cage). Starting from the fourth day of age, birds of two compartments received a continuous lighting program (23L:1D a day; C.L. groups) while birds of the other two compartments received an intermittent lighting program (1L:3D 6 times per day; I.L. groups). Within each lighting program during 22-42 d of age, one group was subjected either to a thermoneutral temperature at 24 °C or heat stress at 35 °C. The results reveal that stress biomarkers, especially the plasma concentrations of corticosterone (CORT), tumor necrosis factor-alpha (TNF-α), and malondialdehyde (MDA) were relieved by 46%, 27%, and 51%, respectively, in the I.L. treatment groups compared to the C.L. program in broiler chicks subjected to heat stress. The liver function was also improved by 24% and 32% in AST and ALT levels, respectively, in the I.L. program compared to the C.L. program in stressed birds. Furthermore, the I.L. program positively influenced the immune response of the heat-stressed broilers. Eventually, the I.L. program increased the heat-stressed broilers' body weight gain and feed conversion ratio. It can be concluded that applying the I.L. program to broiler chickens can effectively improve their physiological balance and growth performance under heat-stress conditions.

Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress.

Heat stress (HS) induces deleterious effects on the performance of laying hens and causes economic losses for poultry industry. This study was carried out to investigate the organic effect of selenium-enriched yeast (SY) on relieving the performance, immunity and physiological deterioration induced by heat stress in laying hens. A total of 324, 28-week-old, Hy-Line Brown commercial chicken layers were randomly distributed into 4 treatments according to a 2 × 2 factorial design, with 9 hens × 9 replicates per treatment (n = 81). From 30 to 34 weeks of age, layers were exposed to 2 temperature treatments (the HS treatment groups): a thermoneutral temperature at 24°C and a heat stress at 35°C. Layers were further assigned into the 2 subgroups according to dietary supplementation with organic selenium-enriched yeast (the SY treatment groups) at either 0 or 0.4 mg/kg diet. Results indicated that all the aspects of the layer performance during the experimental period were impaired by exposure to HS, while SY supplementation improved the layer performance in both the HS and non-HS layers. Intestinal villi disruptions and liver necrotic hepatocytes were observed in the layers exposed to HS, while villi integrity and hepatocytic normality were enhanced by SY treatment. A significant (P < 0.05) decrease in the total leukocyte count, sheep red blood cell (SRBC) antibody titer, and T- and B-lymphocyte proliferation along with an increase in the heterophils/lymphocytes (H/L) ratio were observed in the HS layers compared to non-HS layers. On the contrary, SY treatment significantly (P < 0.05) improved the immune function traits in both the HS layers and non-HS layers. Furthermore, the SY treatment plays an important role in mitigating the oxidative stress and inflammation induced by HS, displaying lower levels of plasma corticosterone, lipid peroxidation, interleukin-1ß, and tumor necrosis factor-α in HS layers supplemented with SY compared to HS layers without SY supplementation. These results conclude that addition of SY to the diet of laying hens could be applied as a potential nutritional approach to relieve the deterioration effects of heat stress on the immunity, physiological status, and productive performance of laying hens.

Citrullus colocynthis Seed Ameliorates Layer Performance and Immune Response under Acute Oxidative Stress Induced by Paraquat Injection.

Oxidative stress is a detrimental physiological state that threatens birds' productivity and general health. Colocynth is an herbal plant known for its bioactive properties, and it is mainly known for its antioxidant effects. This study's purpose was to investigate how effective colocynth seed is at lowering the detrimental impact of acute oxidative stress caused by paraquat (PQ) injection in laying hens. A total of 360 Hy-Line Brown chickens, aged 39 weeks, were gathered and divided into four equal groups (10 hens × 9 replicates) in a 2 × 2 factorial design. The experimental groups were given either a basal diet or the basal diet supplemented with colocynth seed (1% of diet). Starting from week 40 of age and for 7 successive days, the experimental groups were either injected daily with paraquat (5 mg/kg body weight) or with saline (0.5 mL, 0.9% NaCl). Egg production performance with selected stress biomarkers and immunological response parameters were investigated at the end of week 40 of age. Our data revealed a significant reduction in egg production with an increase in blood stress biomarkers (i.e., HSP-70, corticosterone, and H/L ratio) in PQ-injected groups compared with non-stressed groups. Furthermore, an unbalanced redox state was detected in acute oxidative stress groups, with a significant rise in lipid peroxidation level, a reduction in total antioxidant capacity (TAC), and a drop in superoxide dismutase (SOD) and catalase enzyme activity. Supplementing PQ-injected hens with colocynth seed reduced the deleterious effects of acute oxidative stress. There was a significant drop in stress biomarkers with a significant rise in antioxidant enzyme activity and TAC observed in the PQ-injected group provided with colocynth seed supplementation. Remarkably, supplementation of colocynth in the non-stressed group resulted in a significant 27% increase in TAC concentration and 17% higher SOD activity when compared with the non-stressed control group. Colocynth supplementation in the PQ-injected group elevated the total white blood cell count by 25% and improved the B-lymphocyte proliferation index (a 1.3-fold increase) compared with the PQ-injected group that did not receive supplementation. Moreover, the non-stressed colocynth-supplemented group had significantly higher cell-mediated and humoral immune responses than the non-stressed control group. This study demonstrated that colocynth seed supplementation in birds exposed to acute oxidative stress may effectively alleviate its negative impacts on production performance, immunological responses, and redox status. We also inferred that, under normal conditions, colocynth seed can be added to laying hens' diets to stimulate production and ameliorate immune responses.

Blue-Green Algae (Spirulina platensis) Alleviates the Negative Impact of Heat Stress on Broiler Production Performance and Redox Status.

The modern broiler industry faces huge challenges to keep high production quality and quantity, especially under environmental heat stress conditions. The negative effect of heat stress on broiler productivity is mediated by oxidative stress induction. The blue-green alga (Spirulina platensis) has many applications in poultry nutrition with the high levels of bioactive antioxidant compounds, which can alleviate the oxidative stress damage induced by high ambient temperature. The current study was designed to investigate the effects of dietary Spirulina inclusion at different levels on growth performance, redox status, carcass traits, meat quality, blood hematology, and metabolites profile of broilers subjected to cyclic heat stress. A total of 300 one-day-old Cobb-500 broiler chicks were recruited. Starting from day 21 to 42 of age, birds were randomly divided into five treatment groups with 6 replicates × 10 birds per group, where the first one was provided with the basal diet and reared under normal thermal conditions (23 ± 1 °C) to serve as a negative control. Meanwhile, the other four groups were exposed to cyclic heat stress (34 ± 1 °C for 8 h per day) and were fed a basal diet supplemented with Spirulina at a concentration of 0, 0.5, 1 or 1.5%. Spirulina supplementation to heat-stressed broilers was able to alleviate the negative impacts of heat stress on the final average daily gain, body weight and feed conversion ratio, with the best impact observed among the chickens fed 1% Spirulina. Hematological results indicate increasing hemoglobin and hematocrit levels with Spirulina supplementation compared to the non-supplemented stressed group. Further, Spirulina supplementation significantly influenced blood lipid metabolites marked by reduced serum cholesterol and low-density lipoprotein (LDL), and increased high-density lipoprotein (HDL) levels. The lipid peroxidation level was reduced (p < 0.05), while the antioxidant enzyme activity was increased with Spirulina supplementation to the heat-stressed group. Spirulina supplementation at 0.5 or 1% improved carcass dressing, breast and leg percentages. It can be concluded that dietary Spirulina supplementation at 0.5 or 1% to broiler reared under heat stress conditions can effectively improve broiler production performance and balance the redox status.

Modulating Laying Hens Productivity and Immune Performance in Response to Oxidative Stress Induced by E. coli Challenge Using Dietary Propolis Supplementation.

Propolis (PR) is a resin product of bee colonies that has rich bioactive antioxidant and bactericidal compounds. Endotoxin, a byproduct of bacterial growth, is reported to cause progressive induction of endogenous oxidative stress and has negative impacts on individual health and wellbeing. Hereby, we investigated the ability of PR to alleviate the oxidative stress and immunosuppression imposed by avian pathogenic Escherichia coli using laying hen as a based model. In this study, PR was dietary supplemented to hens for 4 weeks at a concentration of 0.1%. At the beginning of the 4th week of the experiment, hens from control and PR treatment were injected with E. coli (O157:H7; 107 colonies/hen) or saline. The results showed significant (p < 0.05) negative impact of E. coli challenge on antioxidant status, immune response and productive performance. PR supplementation reduced (p < 0.05) inflammation markers levels (tumor necrosis factor α (TNFα) and interleukin 1ß (IL-1ß)) and plasma corticosterone concentration. The antioxidant status was ameliorated with dietary PR supplementation to challenged hens, showing significant (p < 0.05) reduction in malondialdehyde (MDA) levels and increasing total antioxidant capacity (TAC) concentrations. Cell mediated, as well as, humeral immune response improved significantly (p < 0.05) with dietary PR verified by the enhancement of T- and B-lymphocyte proliferation and the positive respond to phytohemagglutinin (PHA). Leucocyte cells viability increased significantly and the apoptotic factor forkhead box O3 (Foxo3) was reduced with PR supplementation. The current study revealed that dietary PR supplementation can effectively be used as an organic feed additive to overcome the endogenous oxidative stress induced by endotoxins challenge.

Dietary Supplementation of Probiotic Lactobacillus acidophilus Modulates Cholesterol Levels, Immune Response, and Productive Performance of Laying Hens.

This study examines the effect of dietary supplementation with Lactobacillus acidophilus (LA) on the cholesterol levels, immune response, and productive performance of laying hens. A total of 216, 40-week-old, commercial Hy-Line brown chicken layers were randomly assigned into four treatment groups (18 birds × three replicates per group) and fed diet supplemented with 0 (control), 1 × 109, 21 × 109, and 31 × 109 colony forming units (CFUs) of Lactobacillus acidophilus (LA) per kg of feed for six consecutive weeks. Results show that plasma triglycerides, low-density lipoprotein (LDL) and total cholesterols became lesser, while high-density lipoprotein (HDL) cholesterol became higher in LA-supplemented groups compared to the control. In addition, a significant reduction occurred in the liver and egg yolk cholesterol by LA supplementation. Moreover, the immunological parameters including antibody titer against sheep red blood cells (SRBCs), phytohemagglutinin (PHA)-wattle swelling test, and T- & B-lymphocyte proliferation were enhanced in laying hens supplemented with LA compared to the control hens. While the heterophil to lymphocyte (H/L) ratio decreased with LA supplementation, indicating low stress conditions in the treated hens. These positive effects for LA were further reflected on the productive performance of laying hens and improved egg production, egg weight, egg mass, and feed efficiency. Our findings indicate that LA probiotic could be recommended in laying hens' diets for lowering egg yolk cholesterol with positive impacts on health and performance.

Microbial and Fungal Phytases Can Affect Growth Performance, Nutrient Digestibility and Blood Profile of Broilers Fed Different Levels of Non-Phytic Phosphorous.

A total of 420 day old chicks were divided into seven groups (5 replicates of 12 chicks/group) fed isoproteic and isoenergetic diets. The control group was fed diets containing 0.50%, 0.45% and 0.40% of non-phytic phosphorous (nPP) in starter (1-35), grower (37-56) and finisher (57-64 d) periods, respectively. The three intermediate nPP (IntnPP) groups were fed diets with 0.40%, 0.35% and 0.30% nPP according to the growth period and were submitted to three dietary treatments: unsupplemented; supplemented with 500 FTU/kg diet of an Aspergillus niger phytase (IntnPP_fp) and supplemented with 500 FTU/kg diet of an Escherichia coli phytase (IntnPP_bp). The three low nPP groups fed diets contained 0.30%, 0.25% and 0.20% nPP and were submitted to the same dietary treatments than IntnPP to obtain LnPP, LnPP_fp and LnPP_bp groups. IntnPP and LnPP groups had lower body weight gain and feed, crude protein (CP) and metabolizable energy (ME) intake (p < 0.05) than the control. Feed conversion ratio of IntnPP was more favorable (p < 0.01) than the LnPP group. CP and ME conversion ratios worsened (p < 0.01) in IntnPP and LnPP groups in comparison to the control. The nPP conversion ratio improved (p < 0.01) from the control to the LnPP group. Fungal phytase reduced (p < 0.05) feed, CP, ME and nPP intake than the bacterial one. IntnPP and LnPP diets had a lower digestibility of CP (p < 0.01) and CF (p = 0.01) than the control. IntnPP and LnPP groups showed a higher (p < 0.05) economic efficiency than the control. Blood total protein was the lowest (p < 0.05) in the LnPP group, the control group showed the lowest (p < 0.05) level of albumin and IntnPP group had the lowest (p < 0.01) globulin level. The use of bacterial phytase increased (p < 0.01) total protein and globulin and decreased (p < 0.05) the plasma cholesterol in comparison to fungal phytase. Decreasing nPP levels in colored slow-growing broilers diet negatively affects growth performance and the use of phytase can partly alleviate these negative effects, but the efficiency of different enzyme sources (bacterial or fungal) was tied to the dietary nPP levels.

The Strategy of Boosting the Immune System Under the COVID-19 Pandemic.

The novel coronavirus (SARS-CoV-2) infection (COVID-19) has raised considerable concern on the entire planet. On March 11, 2020, COVID-19 was categorized by the World Health Organization (WHO) as a pandemic infection, and by March 18, 2020, it has spread to 146 countries. The first internal defense line against numerous diseases is personalized immunity. Although it cannot be claimed that personalized nutrition will have an immediate impact on a global pandemic, as the nutritional interventions required a long time to induce beneficial outcomes on immunity development, nutritional strategies are still able to clarify and have a beneficial influence on the interplay between physiology and diet, which could make a positive contribution to the condition in the next period. As such, a specific goal for every practitioner is to evaluate different tests to perceive the status of the patient, such as markers of inflammation, insulin regulation, and nutrient status, and to detect possible imbalances or deficiencies. During the process of disease development, the supplementation and addition of different nutrients and nutraceuticals can influence not only the viral replication but also the cellular mechanisms. It is essential to understand that every patient has its individual needs. Even though many nutrients, nutraceuticals, and drugs have beneficial effects on the immune response and can prevent or ameliorate viral infections, it is essential to detect at what stage in COVID-19 progression the patient is at the moment and decide what kind of nutrition intervention is necessary. Furthermore, understanding the pathogenesis of coronavirus infection is critical to make proper recommendations.