Early Feeding Strategy Mitigates Major Physiological Dynamics Altered by Heat Stress in Broilers.

Heat stress is one of the stressors that negatively affect broiler chickens, leading to a reduction in production efficiency and profitability. This reduction affects the economy in general, especially in hot and semi-hot countries. Therefore, improving heat tolerance of broiler chicks is a key to sustained peak performance, especially under adverse environmental heat stress conditions. The present study investigated three early feed withdrawal regimes (FWD) as a potential mitigation for thermal stress exposure. A total of 240 unsexed one-day-old Cobb-500 chicks were randomly recruited to one of four experimental groups using a completely randomized design (10 birds × 6 replicates). The experimental groups included the control group with no feed withdrawal (control), while the other three groups were subjected to early feed withdrawal for either 24 h on the 5th day of age (FWD-24), 12 h on the 3rd and 5th day of age (FWD-12), or 8 h on the 3rd, 4th, and 5th day of age (FWD-8), respectively. Production performance was monitored throughout the experiment. Meanwhile, blood and liver samples were taken at the end of the experimental period to evaluate major physiological dynamic changes. Our findings demonstrated that under chronic heat stress conditions, FWD treatments significantly improved broilers' production performance and enhanced several physiological parameters compared with the control. Serum levels of thyroid hormones were elevated, whereas leptin hormone was decreased in FWD groups compared with the control. Moreover, serum total protein, globulin, and hemoglobin levels were higher, while total cholesterol and uric acid were lower in the FWD groups. Furthermore, FWD groups showed significantly higher antioxidant marker activity with a significantly lower lipid peroxidation level. Immunoglobulin levels, lysozyme, complement factor C3, and liver heat shock protein 70 (HSP70) concentration were also elevated in FWD compared with the control. Also, serum interleukin-1ß (IL-1ß) and interferon-gamma (IFN-γ) significantly increased with FWD. Based on our findings, early feed withdrawal can be applied as a promising non-invasive nutritional strategy for broilers reared under chronic heat stress conditions. Such a strategy promotes the alleviation of the deleterious effects of heat stress on broiler performance, immunity, and redox status, owing to the onset of physiological adaptation and the development of thermotolerance ability.

Microbiological Indoor and Outdoor Air Quality in Chicken Fattening Houses.

This study was conducted at one of the largest poultry companies in Kuwait during November and December 2019 to evaluate the microbiological threats of Escherichia coli (APEC), Salmonella spp., and Aspergillus fumigatus to chickens in fattening houses by counting and identifying the microorganisms by culturing and pyrosequencing analysis. During the fattening cycle, the temperature and humidity ranged between 23.6°C and 29°C and 64.1% and 87.1%, respectively. The total bacterial population and Aspergillus fumigatus measured in the indoor and outdoor air exhibited a linear relationship during the fattening cycle. The total bacterial and Aspergillus concentrations determined during the cycle ranged between 150 and 2000 CFU/m3 and 0 and 1000 CFU/m3, respectively. E. coli and Salmonella spp. concentrations determined during the cycle ranged between 1 and 220 CFU/m3 and 4 and 110 CFU/m3, respectively. Pyrosequencing analysis of the air inside the houses at the end of the cycle revealed extensive biodiversity in the microorganisms, detecting 32 bacterial genera and 14 species. The identified species belonging to the genera Corynebacterium, Haemophilus, Streptococcus, Veillonella, and Aspergillus were identified as potentially affecting human and broiler health. The emission of potentially pathogenic bacteria to the outdoor environment from chicken housing can pose a considerable risk to human health and environmental microbial pollution. This study could guide the development of integrated control devices for monitoring microbes in broiler production facilities during chicken collection for transport to slaughterhouses.

Corrigendum: The impact of multi-enzyme fortification on growth performance, intestinal morphology, nutrient digestibility, and meat quality of broiler chickens fed a standard or low-density diet.

[This corrects the article DOI: 10.3389/fvets.2022.1012462.].

The impact of multi-enzyme fortification on growth performance, intestinal morphology, nutrient digestibility, and meat quality of broiler chickens fed a standard or low-density diet.

This research aimed to study the impact of supplementation of three multi-enzyme levels (0, 0.1, and 0.2% of feed) and two levels of dietary treatments [standard diet (SD) and low-density diet (LDD)] on growth performance, carcass traits, digestibility, and meat quality of broilers from 1 to 38 days of age. A total of 216 1-day-old Arbor Acres broiler chicks were randomly assigned to a factorial experiment (2 × 3) comprising six dietary treatments, each with six replicates and each replicate with six chickens. The results showed that the LDD significantly reduced body weight gain by 5.0%, compared with the SD. Multi-enzymes significantly improved body weight gain and the production index (PI) relative to the SD. The feed conversion ratio was significantly enhanced with increased multi-enzymes from 1 to 21 days. A significant relation between the multi-enzyme concentration and type of dietary treatment was observed in body weight gain and feed conversion ratio from 1 to 21 days of age. Nitrogen-free extract digestibility was significantly increased by using the SD diet compared with using the LDD. Multi-enzyme supplementation improved the digestibility of dry matter, crude protein, crude fiber, and nitrogen-free extract in the LDD. A significant relationship was found between the multi-enzyme concentration and type of dietary treatment on the pancreas, liver, and intestinal length percentages. The meat dry matter concentration was significantly higher in the LDD group than in the SD group. The low-density diet significantly reduced the total revenue compared with the SD, whereas broilers fed the SD recorded significantly higher total revenue and economic efficiency than those fed the LDD. The low-density diet significantly increased economic efficiency compared with the SD. Multi-enzymes significantly increased the total revenue, net revenue, and economic efficiency than the standard set. In conclusion, using multi-enzymes in broiler diets improved body weight gain. The LDD with multi-enzymes showed enhanced body weight gain compared with the SD without multi-enzymes.

Cellular and humoral immune response between snail hosts and their parasites.

In invertebrates, the innate immune system protects against a wide range of microbiological infections. Several immunological processes are involved in the interactive immune response between snails and their parasites, including phagocytosis, nitric oxide synthesis, phenol oxidase activity, lysozymes, and lectin formation. The immunological responses connected to the interaction between snails and parasites are discussed in detail in the current research. Understanding the nature of these interactive reactions will enable scientists to explore approaches to eliminate and cure parasitic infections.

The relation between avian coronaviruses and SARS-CoV-2 coronavirus.

The coronaviruses (CoVs) are a family of ribonucleic acid viruses that are present in both mammals and birds. SARS-CoV and MERS-CoV originated in bats, and there is a possibility that this could be the case for SARS-CoV-2 as well. There is already evidence that a probable intermediary host is responsible for the emergence of viruses in humans as was the case for SARS-CoVs and MERS-CoV. As the SARS-CoV-2 originated from a live animal market, there is always the question if domestic animals are susceptible to these viruses and the possible risk of zoonotic transmission with mammals, including humans. This uncertainty of the transmission of the COVID-19 virus between humans and animals is of great significance worldwide. Hence, this paper focuses on the avian CoVs and their possible relation and interaction with SARS-CoV-2.

Effects From Dietary Addition of Sargassum sp., Spirulina sp., or Gracilaria sp. Powder on Immune Status in Broiler Chickens.

Algae are innovative and significant nutrient sources with various health benefits when used as additives in animal feed. The study aims to examine the effect of different inclusions of three algae species, Sargassum sp., Spirulina sp., and Gracilaria sp. on the immune response of broiler chickens, as measured by the cellular immune response, humoral immune response, intestinal microbial counts, hindgut acidosis, and hematological measures. Here is a list of the seven experimental treatments (TRT). TRT 1 was the control group without algae; TRT 2 was supplemented with Sargassum sp. at 1% of the diet; TRT 3 with Sargassum sp. at 2% of the diet; TRT 4 with Spirulina sp. at 5% of the diet; TRT 5 with Spirulina sp. at 7.5% of the diet; TRT 6 with Gracilaria sp. at 0.5% of the diet; and TRT 7 Gracilaria sp. at 1% of the diet. Each treatment involved five replicates with 17 broiler chickens each, and the analyses were triplicated. The results showed that including algae in the feed ration of broiler chickens induces a higher cellular response than the control group, represented by T-cell response in the wattle area (P = 0.037). Sargassum sp. at 1 and 2% enhanced IgA antibody titers significantly and Gracilaria sp. at 5% enhanced IgY antibody titers, P = 0.045 and P = 0.030, respectively. All algal inclusions inhibited the growth of Salmonella sp. and improved LAB counts in the intestine of broilers, excepting the Gracilaria sp. at 0.5%, where LAB counts were similar to the control group. The E. coli counts decreased numerically but not significantly. Blood lymphocytes were enhanced while white blood cells (WBC) and heterophils were decreased as a results of algal inclusions. In conclusion, supplementing broiler chickens with algae could enhance their cellular and humoral immune status and promote healthy microflora in their guts.

Major Molecular Factors Related to Leishmania Pathogenicity.

Leishmaniasis is a major health problem with 600k - 1M new cases worldwide and 1 billion at risk. It involves a wide range of clinical forms ranging from self-healing cutaneous lesions to systemic diseases that are fatal if not treated, depending on the species of Leishmania. Leishmania sp. are digenetic parasites that have two different morphological stages. Leishmania parasites possess a number of invasive/evasive and pathoantigenic determinants that seem to have critical roles in Leishmania infection of macrophages which leads to successful intracellular parasitism in the parasitophorous vacuoles. These determinants are traditionally known as "virulence factors", and are considered to be good targets for developing specific inhibitors to attenuate virulence of Leishmania by gene deletions or modifications, thus causing infective, but non-pathogenic mutants for vaccination. Pathway of biosynthesis is critical for keeping the parasite viable and is important for drug designing against these parasites. These drugs are aimed to target enzymes that control these pathways. Accordingly, maintaining low level of parasitic infection and in some cases as a weapon to eradicate infection completely. The current paper focuses on several virulence factors as determinants of Leishmania pathogenicity, as well as the metabolites produced by Leishmania to secure its survival in the host.

Modulating the Growth, Antioxidant Activity, and Immunoexpression of Proinflammatory Cytokines and Apoptotic Proteins in Broiler Chickens by Adding Dietary Spirulina platensis Phycocyanin.

This study investigated the dietary effect of Spirulina platensis phycocyanin (SPC) on growth performance (body weight (BW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR)) at starter, grower, and finisher stages, intestinal histomorphology, serum biochemical parameters, inflammatory and antioxidant indices, and proinflammatory cytokines (tumor necrosis factor-α and caspase-3) immune expression in broiler chickens. In total, 250 one-day-old chicks (Ross 308 broiler) were randomly allotted to five experimental groups (5 replicates/group, 10 chicks/replicate) and fed basal diets supplemented with five levels of SPC (0, 0.25, 0.5, 0.75, and 1 g kg-1 diet) for 35 days. Compared with SPC0 treatment, different SPC levels increased the overall BW and BWG without affecting the total feed consumption. However, the FCR decreased linearly with an increase in supplementation level. The serum levels of total proteins, albumin, globulins, and growth hormone increased linearly by increasing levels of SPC supplementation. Further, SPC supplementation increased the thyroxin hormones without affecting serum glucose and leptin levels. Serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) values decreased in broilers fed SPC0.250 and SPC1 diets. Triglycerides (TG) decreased in SPC0.25-, SPC0.75-, and SPC1-treated groups. Though antioxidant enzyme activities (total antioxidant capacity, catalase, and superoxide dismutase) increased linearly and quadratically, malondialdehyde (MDA) decreased linearly by increasing the SPC level. There was no effect on serum proinflammatory cytokines IL1ß levels. Immunolabelling index of caspase-3 and tumor necrosis factor-α (TNF-α) were downregulated by SPC supplementation. The intestinal histomorphology is represented by increased villus height, the villus height to crypt depth ratio, and numbers of goblet cells in different sections of the small intestine. In conclusion, SPC supplementation is beneficial in broiler chicken diets due to its growth-promoting, antioxidant, and anti-inflammatory properties.

Dietary Supplementation of Fructooligosaccharides Enhanced Antioxidant Activity and Cellular Immune Response in Broiler Chickens.

This study investigated the impact of various concentrations of fructooligosaccharides (FOS) prebiotic on the production performance, antioxidant status, and immune response of broiler chicken. The FOS was used at 0, 0.3, 0.5, and 0.7%. The cycle included 340 broilers distributed into 4 batteries, with 85 broiler chickens in each battery. There were 5 replicates with 17 broiler chickens each, and the analyses were triplicated. The studied parameters were production performance, antioxidant status, hematological measurements, cellular and humoral immune response, intestinal acidosis, intestinal microbial counts, and volatile fatty acid (VFA) level in the hindgut. Results showed that broiler chickens fed 0.7% of FOS had significantly higher body weight gain than the control group and the groups fed 0.3% and 0.5% of FOS. Supplementing broiler feed with FOS at all levels increased the total antioxidant capacity (TAC) and reduced the malondialdehyde of the sera (P = 0.015 and 0.025, respectively). Liver catalase enzyme in the broiler chickens fed 0.5 and 0.7% of FOS was higher than that of the control group and the group fed 0.3% of FOS (P = 0.001). However, the liver MDA of the control group was higher than that of all the other groups (P = 0.031). The total WBC and heterophils % were the highest after supplementing broilers with 0.7% FOS (P = 0.004 and 0.003, respectively) at 3 wks of age. Conversely, lymphocytes and monocytes were the lowest for the 0.7% FOS group (P = 0.030 and 0.020, respectively). Dietary 0.05 and 0.7% of FOS induced the highest cellular response compared to the other treatments (P = 0.020). Thymus, bursa of Fabricious, and spleen weights were enhanced after FOS supplementation, which indicates a higher specific cellular response. To conclude, FOS prebiotic at all levels can be utilized safely to enhance the antioxidant activity and the cellular immune response of broiler chickens. Using 0.7% of FOS resulted in higher body weight of broilers. Accordingly, this amount of FOS is sufficient to reach the required results.

Effect of Ginger Powder on Production Performance, Antioxidant Status, Hematological Parameters, Digestibility, and Plasma Cholesterol Content in Broiler Chickens.

The effect of dietary ginger powder on the production performance, digestibility, hematological parameters, antioxidant status, dietary oxidation stability, and plasma cholesterol content of broiler chickens was investigated. Ginger powder was included in the diet at 0, 5, 10, or 15 g/kg. Total antioxidant capacity and malondialdehyde in sera samples, superoxide dismutase activity, glutathione peroxidase, catalase, and malondialdehyde in liver samples, and the peroxide value and acid value of the stored diets were evaluated. The results showed that ginger inclusion significantly improved antioxidation indices in broiler sera and liver. Total body weight gain in ginger-supplemented birds was higher than that of control birds (p < 0.048). Supplementing the broiler chickens with ginger powder reduced total feed consumption (p < 0.031). White blood cell counts and the percentage of heterophils in the blood were increased in birds that received ginger supplementation (p < 0.001). The inclusion of ginger in the diet improved dry matter digestibility, crude protein utilization, crude fiber utilization, and ether extract utilization. In addition, blood cholesterol, triglyceride, and very low-density lipoprotein levels were decreased (p < 0.001), and high-density lipoprotein and levels were increased, following the inclusion of ginger in the diet (p < 0.001).

Potential Effects of Anthocyanin-Rich Roselle (Hibiscus sabdariffa L.) Extract on the Growth, Intestinal Histomorphology, Blood Biochemical Parameters, and the Immune Status of Broiler Chickens.

The potential effects of anthocyanin-rich roselle, Hibiscus sabdariffa L. extract (ARRE) on the growth, carcass traits, intestinal histomorphology, breast muscle composition, blood biochemical parameters, antioxidant activity, and immune status of broiler chickens were evaluated. In the present study, Hibiscus acidified ethanolic extract was reported to have a total anthocyanin content of about 359.3 mg cyanidin 3-glucoside/100 g DW, total polyphenol concentration (TPC) of about 598 mg gallic acid equivalent (GAE)/100 g DW, and total flavonoids (TFs) of about 100 mg quercetin equivalent (QE)/100 g DW. Two-hundred-fifty one-day-old chicks (Ross 308 broiler) (87.85 gm ± 0.32) were randomly allotted to five experimental groups and fed on basal diets supplemented with five levels of ARRE: 0, 50, 100, 200, and 400 mg Kg-1 for 35 days. Dietary ARRE addition did not improve the birds' growth and carcass traits. Supplemental ARRE increased the n-3 polyunsaturated fatty acids (PUFA) (ω-3) percentage in the breast muscle. Dietary ARRE increased the villous height, and the ARRE100 group raised the villus height to crypt depth ratio. Dietary ARRE increased the immunoexpression of immunoglobulin G (IgG) in the spleen. The serum thyroxine hormone (T4) level was higher in the ARRE200 group. The serum growth hormone level was increased by ARRE addition in a level-dependent manner. According to the broken-line regression analysis, the optimum inclusion level of ARRE was 280 mg Kg-1. All levels of supplemental ARRE decreased the serum triglyceride level. The serum total antioxidant capacity (TAC) was increased in the ARRE100-ARRE400 groups, the serum superoxide dismutase (SOD) level was increased in the ARRE200 group, and the serum malondialdehyde (MDA) level was decreased by increasing the ARRE level. Supplemental ARRE significantly increased the serum levels of lysozymes and IL10. The serum complement 3 (C3) level was increased in ARRE200 and ARRE400 groups. It can be concluded that dietary ARRE addition had many beneficial effects represented by the improvements in the bird's metabolic functions, blood biochemistry, intestinal morphology, antioxidant activity, immune status, and higher ω-3 content in the breast muscles. However, it had no improving effect on the birds' growth.

Black Pepper or Radish Seed Oils in a New Combination of Essential Oils Modulated Broiler Chickens' Performance and Expression of Digestive Enzymes, Lipogenesis, Immunity, and Autophagy-Related Genes.

Optimal combinations of essential oils (EOs) can enhance performance and maintain poultry productivity. The effects of EOs with black pepper oil (BPO) or radish seed oil (RSO) on performance and the expression of digestive enzymes, lipogenesis, immunity, and autophagy-related genes in broiler chickens were explored. Six dietary treatments for 300 one-day-old chicks were allocated as follows: controls were fed a basal diet, one group was fed an EO-supplemented diet (1.5 g/kg diet of parsley, mint, and carrot seed oils (1:1:1)), and other groups received Eos + BPO0.25, Eos + BPO0.5, Eos + RSO0.25, and Eos + RSO0.5 treatments, with a basal diet containing EOs plus BPO or RSO at the level of 0.25 or 0.5 g/kg, respectively. Supplementation with 0.5 g/kg of EOs plus BPO or RSO resulted in the most improved maximum BWG and FCR in broiler chickens. The lactobacilli population was increased in Eos + BPO0.5, followed by EOs + RSO0.5, unlike in the control. The highest expression of the CCK and PNLIP genes was identified in the Eos + BPO group. The FAS and ACC genes were upregulated, while the IgA and IL-10 genes were downregulated, with EOs plus RSO or BPO. The group that received Eos + BPO0.5, followed by Eos + RSO0.5, displayed patterns of higher expression for atg5, atg7, and atg12, with lower expression of mTOR. In summary, a new combination of EOs with 0.5 g/kg BPO had potential growth-promoting and immune-boosting effects in broiler chickens.

Antioxidant Status, Blood Constituents and Immune Response of Broiler Chickens Fed Two Types of Diets with or without Different Concentrations of Active Yeast.

Probiotics, such as active yeasts, are widely used to enhance poultry production and reduce feeding costs. This study aimed to investigate the antioxidant and immune responses of broilers to different concentrations of active Saccharomyces cerevisiae (SC) when supplemented to two types of diets. A total of 216 1-day-old Arbor Acres unsexed chicks were used in a factorial design, involving two feeds (regular- versus low-density diet) and three concentrations of SC (0%, 0.02% and 0.04%). The results revealed that the low-density diet reduced the body weight and production index of broilers. The addition of SC improved the production index more than the control diet. Total antioxidant capacity (TAC), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and eosinophils were significantly higher in response to the regular-density diet than the low-density diet; however, phagocytic activity (PA), lymphocyte and lysozyme activity (LYS) were lower. Saccharomyces cerevisiae reduced ALT, AST, malondialdehyde (MAD) and TAC more than the standard set, but improved packed cell volume (PCV), hemoglobin (Hgb), red blood cells (RBCs), lymphocytes, monocytes, heterophils, phagocytic index (PI) and the immune response to Newcastle disease virus (NDV) and avian influenza (AI). In conclusion, supplementation of a regular- or low-density diet with SC at a concentration of 0.02% or 0.04% improved the antioxidant parameters, immune status and production index of broilers against stress and infectious agents.

Performance, Serum Biochemical and Immunological Parameters, and Digestive Enzyme and Intestinal Barrier-Related Gene Expression of Broiler Chickens Fed Fermented Fava Bean By-Products as a Substitute for Conventional Feed.

Improving the nutritional quality of unconventional feed ingredients such as fava bean by-products can enhance their utilization by broiler chickens. Hence, the quality of fermented fava bean by-products (FFB), in addition to growth, nutrient digestibility, digestive enzyme, and intestinal barrier-related gene expression, and serum biochemical and immunological parameters were evaluated in response to different levels of FFB. A total of 500 1-day-old broiler chicks (46.00 ± 0.388 g) were allocated to five groups with 10 replicates each (100 chicks per treatment). The first group was fed a corn-soybean diet (control diet), and the other four groups were fed a diet containing 5, 15, 25, and 35% FFB for 38 days. Birds fed 25% FFB exhibited maximum body weight gain (increase by 12.5%, compared with the control group) and the most improved feed conversion ratio. Additionally, birds fed FFB at 15, 25, and 35% showed improved dry matter and crude protein digestibility. Moreover, birds fed FFB at 25 and 35% exhibited a decrease in ileal pH and an increase in fiber digestibility (p < 0.05). Upregulation of digestive enzyme genes (AMY2A, PNLIP, and CCK) was observed in groups fed with FFB. The most prominent upregulation of genes encoding tight junction proteins (claudin-1, occludin, and junctional adhesion molecules) in the duodenum was observed in chicks fed 25 and 35% FFB (increase of 0.66-, 0.31-, and 1.06-fold and 0.74-, 0.44-, and 0.92-fold, respectively). Additionally, the highest expression level of enterocyte protective genes [glucagon-like peptide (GLP-2), mucin-2 (MUC-2), and fatty acid-binding protein (FABP-6)] was detected in duodenum of chicks fed high levels of FFB. Substitution of corn-soybean diet with FFB had an inhibitory effect on cecal pathogenic microbes (Escherichia coli and Clostridium perfringens) and increased beneficial microflora (Lactobacilli and Bifidobacterium), especially at high levels. Additionally, an increase was observed in IgM and lysozyme activity, with no effect on IgA in all groups fed FFB. All levels of FFB decreased cholesterol levels. Based on our results, we concluded that substitution of corn-soybean diet with FFB can improve the growth rate and nutrient digestibility of broiler chickens, enhance their intestinal barrier functions, and increase the number of beneficial microorganisms. Using FFB at 25% had a positive effect on the growth performance of broiler chickens, and it could be utilized in poultry farms.

Promising Role of Growth Hormone-Boosting Peptide in Regulating the Expression of Muscle-Specific Genes and Related MicroRNAs in Broiler Chickens.

Appropriate skeletal muscle development in poultry is positively related to increasing its meat production. Synthetic peptides with growth hormone-boosting properties can intensify the effects of endogenous growth hormones. However, their effects on the mRNA and miRNA expression profiles that control muscle development post-hatching in broiler chicks is unclear. Thus, we evaluated the possible effects of synthetic growth hormone-boosting peptide (GHBP) inclusion on a chicken's growth rate, skeletal muscle development-related genes and myomiRs, serum biochemical parameters, and myofiber characteristics. A total of 400 one-day-old broiler chicks were divided into four groups supplied with GHBP at the levels of 0, 100, 200 and 300 µg/kg for 7 days post-hatching. The results showed that the highest levels of serum IGF-1 and GH at d 20 and d 38 post-hatching were found in the 200 µg/kg GHBP group. Targeted gene expression analysis in skeletal muscle revealed that the GHBP effect was more prominent at d 20 post-hatching. The maximum muscle development in the 200 µg/kg GHBP group was fostered by the upregulation of IGF-1, mTOR, myoD, and myogenin and the downregulation of myostatin and the Pax-3 and -7 genes compared to the control group. In parallel, muscle-specific myomiR analysis described upregulation of miR-27b and miR-499 and down-regulation of miR-1a, miR-133a, miR-133b, and miR-206 in both the 200 and 300 µg/kg GHBP groups. This was reflected in the weight gain of birds, which was increased by 17.3 and 11.2% in the 200 and 300 µg/kg GHBP groups, respectively, when compared with the control group. Moreover, the maximum improvement in the feed conversion ratio was achieved in the 200 µg/kg GHBP group. The myogenic effects of GHBP were also confirmed via studying myofiber characteristics, wherein the largest myofiber sizes and areas were achieved in the 200 µg/kg GHBP group. Overall, our findings indicated that administration of 200 µg/kg GHBP for broiler chicks could accelerate their muscle development by positively regulating muscle-specific mRNA and myomiR expression and reinforcing myofiber growth.

Dietary source of polyunsaturated fatty acids influences cell cytotoxicity in broiler chickens.

The current study aims to investigate the effects of dietary source of n-3 polyunsaturated fatty acids (PUFA) on immune response in broiler chickens, represented by cytotoxic cell activity. A total of 255 one-day-old male Cobb 500 broiler chickens were fed on fish oil (FO)-, flaxseed oil-enriched diets at 50 and 19 g/kg, respectively, in addition to the soybean-based control diet. At slaughter, samples of blood and spleen were harvested from 20 birds/treatment (n = 20). The immune tissues' fatty acid profile was analyzed by gas chromatography, and the cytotoxic cell activity was investigated. The results showed that supplementing broiler chickens with diets rich in n-3 PUFA had a substantial effect on the broiler immune tissues' fatty acid profile. Cytotoxic cell activity was significantly higher in splenocytes and peripheral blood mononuclear cells (PBMCs) from broilers fed flaxseed oil than those provided FO and the soybean control diet. These results suggest that flaxseed oil may be used to enrich chickens with n-3 PUFA and improve the immune status of chicken flocks to resist diseases.

Effects of ecofriendly synthesized calcium nanoparticles with biocompatible Sargassum latifolium algae extract supplementation on egg quality and scanning electron microscopy images of the eggshell of aged laying hens.

In the present study, 200 Brown commercial egg-type layers (60 wk old) were used to study the effects of different levels of ecofriendly synthesis of calcium (Ca) nanoparticles (0.0, 0.50, 1.0, and 1.5 g/kg diet) with biocompatible Sargassum latifolium algae extract (SL-CaNps) on exterior egg quality traits, electronic microscopic view of eggshells, Ca and phosphorus (P) retention, serum Ca and P concentrations, and the histology of the uterus. Hens fed with dietary SL-CaNps powder had higher egg weight and shell weight % values than those of the control group. All SL-CaNps treatment groups had the greatest values of shell weight per unit surface area and shell thickness. Dietary supplementation of SL-CaNps at graded levels up to 1.5 g/kg diet had higher serum Ca and inorganic P levels than that of the control. Laying hens fed with SL-CaNps-added diets had beneficial effects on shell ultrastructure in terms of well-developed palisade and mammillary layers. The numbers of apical cells along the branched tubular gland were greater in SL-CaNps-treated groups than those of control. Conclusively, supplementing SL-CaNps powder up to 1.5 g/kg to the diet of laying hens improved eggshell thickness, shell weight% and shell weight per unit surface and has no adverse effect on their eggshell quality or electronic microscopic view of their eggshell.

Effects of Phenolic-Rich Onion (Allium cepa L.) Extract on the Growth Performance, Behavior, Intestinal Histology, Amino Acid Digestibility, Antioxidant Activity, and the Immune Status of Broiler Chickens.

The effect of phenolic-rich onion extract (PROE), as a feed additive, was evaluated on the growth, carcass traits, behavior, welfare, intestinal histology, amino acid ileal digestibility "AID%," and the immune status of broiler chicks for 35 days. A total number of 400, 1-day-old broiler chicks (45.38 g ± 1.35) were allocated to four different treatments with 10 replicates each (100 chicks/treatment) consisting of: T1, basal diet without additives (control treatment) (PROE0); T2, basal diet + phenolic-rich onion extract (1 g/kg diet) (PROE1); T3, basal diet + phenolic-rich onion extract (2 g/kg diet) (PROE2); and T4, basal diet + phenolic-rich onion extract (3 g/kg diet) (PROE3). An increase in the final body weight "FBW," bodyweight gain "BWG," and feed consumption was observed (P < 0.05) at different PROE levels. Also, the thymus and bursa percentages were increased in the PROE2 and PROE3 treatments (P < 0.05). The chicks fed on PROE supplemented diets had increased frequency of feeding and drinking and showed comfortable behavior (P < 0.05) with lesser aggression (P < 0.05). Additionally, an increase was observed in the antioxidant enzyme activity, phagocytic %, phagocytic index, and serum lysozyme activity in PROE supplemented treatments, with the best outcome reported in the PROE3 treatment (P < 0.01). IgM was increased in the birds fed with PROE2 and PROE3 diets (P < 0.01). PROE supplementation increased the AID% of lysine and methionine (P <0.01), PROE3 treatment increased the AID% of threonine (P < 0.05), and PROE2 and PROE3 treatments increased the AID% of leucine and isoleucine (P < 0.05). Besides, PROE2, and PROE3 treatments increased the villus height and width, mucosal thickness, and goblet cell count from the duodena, jejuna, and ilea (P < 0.05) compared to control treatment. Based on these results, we concluded that the dietary addition of phenolic-rich onion extracts can improve the growth rate of broiler chicken by improving the AID% of amino acids and intestinal histology. Also, it can improve the welfare, antioxidant enzymes activity, and immune status of the birds. Phenolic-rich onion extracts can be used as a natural growth promoter in the poultry feed for good health and improved performance.

Effect of Egyptian Leek Leaf Extract Supplementation on Productive and Economic Performance of Broilers.

Antibiotic growth promoters have been used to improve growth and feed conversion in the poultry industry for a long time; however, they were banned because of several life-threatening side effects in animals, poultry, and humans. This work was carried out to investigate the effect of leek (Allium ampeloprasum var. kurrat) leaf extract (LLE) as a non-traditional growth promoter and feed additive on growth performance, carcass characteristics, serum biochemical parameters, and economic efficiency of broilers. Hubbard unsexed 1-day-old broilers (n = 250) were fed with diets supplemented with LLE for 42 days. The experimental chicks were randomly assigned to one of the five treatment groups varying in LLE quantity in diets: 0% (control), 0.05, 0.1, 0.15, and 0.2%, with five replicates per treatment (50 chicks/treatment or 10 chicks/replicate). Results showed that LLE supplementation improved (P < 0.05) different growth performance parameters. Furthermore, dietary LLE not only decreased serum total cholesterol, triglyceride, low-density lipoprotein, and glucose levels but also increased serum high-density lipoprotein level compared to the control diet. The weight percentages of dressing (P = 0.022) and liver (P = 0.041) showed a marked increase after the addition of LLE. Return, net profit, and collective efficiency measures were increased (P = 0.001) in all LLE groups compared with the control group. Broilers that fed on diets containing 0.2% LLE showed the highest growth and economic efficiency. It could be concluded that supplementation with LLE in broilers has growth-promoting effects, improved biochemical parameters, carcass quality, and promoted economic efficiency through maximizing both return and net profit.