Effects of phytobiotic feed additives on growth traits, blood biochemistry, and meat characteristics of broiler chickens exposed to Salmonella typhimurium

Characterization and antibacterial application of peppermint essential oil nanoemulsions in broiler

In order to mitigate the risk of antibiotic resistance in poultry, scientists nowadays consider plant secondary metabolites to be a major organic antibacterial substitute. This study aimed to characterize and investigate the in silico, in vitro, and in vivo antibacterial effects of peppermint essential oil (PEO) in the form of a nanoemulsion (NE), termed PEONE. Menthol as a major compound of PEO has been identified by gas chromatography and mass spectroscopy (GCMS) analysis as 32.3 %, while lower droplet size, polydispersity Index (PDI), and optimum zeta potential values depicted the stability of PEONE have been observed and validated by transmission electron microscopy (TEM) micrograph image. In silico antibacterial activity was studied by molecular docking of menthol and enrofloxacin with Topoisomerase IV protein (PDB: 1s16;) of Escherichia coli K12 MG1655 and this effect was validated by in vitro and in vivo analysis. In vitro analysis, sustained release of PEONE has been observed against Escherichia coli and Staphylococcus aureus. In this study for in vivo experiments (n = 90) day-old broiler chicks were distributed into 6 dietary treatments with 5 replicates of 3 birds per replication. Dietary treatments included 1) Negative control (basal diet), 2) Positive control (basal diet + 200 µl enrofloxacin), 3) 25 µl PEONE + basal diet, 4) 50 µl PEONE + basal diet, 5) 75 µl PEONE + basal diet, and 6) 100 µl PEONE + basal diet. Analyzed data by different statistical tools confirmed that PEONE significantly affected body weight gain (BWG) with an improved feed conversion ratio (FCR) compared to the control group. A significant increase in cecal Lactobacillus count and a decrease in total coliform was observed. Positive effects on physiological parameters, visceral organs, and meat quality characteristics have been observed. In conclusion, our experiments suggest that PEONE can be used in the broiler industry as a substitute for antibiotics to minimize bacterial resistance.

Progress on the prevention of poultry Salmonella with natural medicines

Salmonella infection is an acute and systemic disease of poultry, primarily affecting young birds. The mortality rate of chicken within one week of age can reach up to 40 %. Surviving individuals may become carriers of the bacteria, leading to latent infections that can result in bacterial residues in meat and egg products, posing serious threats to human food safety and health. Antibiotic therapy is one of the most conventional treatments for Salmonella infections in birds. However, the current abuse of antibiotics has accelerated the mutation of pathogenic bacteria to generate antibiotic-resistant strains. Thus, the effectiveness of treatment with antibiotics alone is gradually diminishing. To address this threat, researchers have explored the use of natural products to enhance the immune system of poultry for preventing Salmonella infections. This study aims to provide a comprehensive review, systematically summarizing recent research progress of the application of natural medicines on poultry Salmonella infection.

The Effect of Phytogenic Additive in Broiler's Diet on Production Results, Physicochemical Parameters, and the Composition of Volatile Organic Compounds of Broiler Meat Assessed by an Electronic Nose System

The primary objective of this study was to investigate the impact of a phytogenic additive (PA) in broiler chickens' diet on production, physiochemical parameters, and the profile of volatile organic compounds present in broiler chickens' meat. The experiment was conducted in a commercial chicken house, where Ross 308 broiler chickens were divided into two groups, each consisting of 65,000 broilers. One group was fed a diet supplemented with 100 ppm of PA throughout the rearing period. The primary chemical composition of the meat and its physicochemical parameters were determined. A visual assessment of breast muscles for defects and volatile organic compounds were evaluated using an electronic nose system. No statistically significant differences were shown in the production performance of the chickens; while summarizing all production parameters, a higher EPEF index of 31 points in the experimental group was highlighted. Breast muscle quality showed differences in drip loss and WHC (p ≤ 0.01) in favor of the experimental group, and a lower cutting force value (p ≤ 0.05) was found for breast muscles from the experimental group. The group also had a lower proportion of muscles with a white striping defect, and the results of volatile organic compound profiling showed the most aroma units.

Combined Effect of Nigella sativa and Kefir on the Live Performance and Health of Broiler Chickens Affected by Necrotic Enteritis

Coccidiosis and necrotic enteritis (NE) are prevalent poultry ailments worldwide, leading to decreased live performance and elevated mortality rates without antibiotic usage. This study evaluated Nigella sativa (black cumin) seeds (BCS) and kefir as alternatives to antibiotics for broilers. An in vivo study over a 28-day period, using 384 Cobb 500 male broilers organized into six treatment groups as part of a completely randomized block experimental design was conducted. Each treatment group included eight replicates, with each replicate containing eight birds. The treatments included positive control, negative control, antibiotic control, 5% BCS in feed, 20% kefir in drinking water, and a combination of 5% BCS and 20% kefir. NE was induced in broilers by administering ~5000 oocysts of Eimeria maxima orally on day 14, followed by inoculation with about 108 CFU/mL of Clostridium perfringens (Cp) (strain Cp#4) on days 19, 20, and 21. Live performance metrics including feed intake, body weight gain, and feed conversion were assessed in broilers. Additionally, NE disease outcomes such as lesion scores, mortality rates, and Cp populations in cecum were determined during the study. The BCS, kefir, and the combination had no detrimental effect on broiler live performance. BCS-treated and combination groups had lower NE scores (p > 0.05) in comparison to the positive control and exhibited no significant difference (p > 0.05) from antibiotic control. Additionally, treatment groups and antibiotic control were not significantly different (p > 0.05) in mortality, whereas the BCS and kefir combination significantly reduced (p < 0.05) mortality to 14.1% compared to 31.3% for the positive control. C. perfringens vegetative cells significantly decreased (p < 0.05) in treatments with BCS, kefir, and their combination on days 22 and 28 compared to the positive control. On day 22, Cp sores were significantly lower (p < 0.05) for the kefir and combination treatments compared to the positive control. In conclusion, BCS and kefir successfully reduced C. perfringens infection and mortality without any detrimental impact on broiler live performance with the combined treatment being the most effective. These results suggest that BCS and kefir could serve as potential alternatives to antibiotics in managing NE.

Exploring the efficacy of a novel prebiotic-like growth promoter on broiler chicken production performance

This study attempts to isolate a candidate growth promoter from the ovine paunch waste and scrutinize its effects on the production performance of broiler chickens as compared to mannan-oligosaccharide (MOS), a prebiotic, and lincomycin, an antibiotic growth promoter (AB). The paunch waste collected from slaughtered sheep was processed to remove particulate matter. The clarified liquid was then added to an excess of ethanol (1:9 ratio), and the resultant precipitate {(novel growth-promoting paunch extract (NGPE)} was collected, dried, and stored. In vitro increase in cell density for probiotic bacteria viz. Lactobacillus rhamnosus and Enterococcus faecalis (Log10 CFU/ml) were significantly higher (P < 0.01) in NGPE supplemented media (2.78 ± 0.11 and 2.77 ± 0.10) as compared to that on MOS (1.28 ± 0.05 and 2.49 ± 0.09) and glucose (1.09 ± 0.04 and 1.12 ± 0.04) supplemented media. In the in-vivo trial of six weeks duration with broiler chickens (Cobb-400), NGPE supplementation resulted in significantly higher growth in weeks IV (P < 0.05) and VI (P < 0.01) of age in comparison to MOS and AGP supplemented groups, a lower (P < 0.01) cumulative feed conversion ratio in comparison to MOS supplemented groups, and a higher (P < 0.01) cumulative protein efficiency ratio compared to MOS and AGP supplementation. NGPE supplementation also lowered lipid peroxidation (P < 0.01), increased reduced glutathione activity (P < 0.01) in chicken erythrocytes, and boosted the lactic acid bacteria count in the cecal contents (P < 0.01). This is the first report of the isolation of a paunch waste extract that increased the in vitro growth of probiotic bacteria and improved the production performance of broiler chickens.

The induced and intrinsic resistance of Escherichia coli to sanguinarine is mediated by AcrB efflux pump

IMPORTANCE

The use of plant extracts is increasing as an alternative to synthetic compounds, especially antibiotics. However, there is no sufficient knowledge on the mechanisms and potential risks of antibiotic resistance induced by these phytochemicals. In the present study, we found that stable drug resistant mutants of E. coli emerged after repetitive exposure to sanguinarine and demonstrated that the AcrB efflux pump contributed to the emerging of induced and intrinsic resistance of E. coli to this phytochemical. Our results offered some insights into comprehending and preventing the onset of drug-resistant strains when utilizing products containing sanguinarine.

Evaluation of the Antimicrobial Activity of a Formulation Containing Ascorbic Acid and Eudragit FS 30D Microparticles for the Controlled Release of a Curcumin-Boric Acid Solid Dispersion in Turkey Poults Infected with Salmonella enteritidis: A Therapeutic Model

The selection of components within a formulation or for treatment must stop being arbitrary and must be focused on scientific evidence that supports the inclusion of each one. Therefore, the objective of the present study was to obtain a formulation based on ascorbic acid (AA) and Eudragit FS 30D microparticles containing curcumin-boric acid (CUR-BA) considering interaction studies between the active components carried out via Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC) to minimize antagonistic effects, and comprehensively and effectively treat turkey poults infected with Salmonella enteritidis (S. enteritidis). The DSC and FTIR studies clearly demonstrated the interactions between AA, BA, and CUR. Consequently, the combination of AA with CUR and/or BA should be avoided, but not CUR and BA. Furthermore, the Eudragit FS 30D microparticles containing CUR-BA (SD CUR-BA MP) showed a limited release of CUR-BA in an acidic medium, but they were released at a pH 6.8-7.0, which reduced the interactions between CUR-BA and AA. Finally, in the S. enteritidis infection model, turkey poults treated with the combination of AA and SD CUR-BA MP presented lower counts of S. enteritidis in cecal tonsils after 10 days of treatment. These results pointed out that the use of an adequate combination of AA and CUR-BA as an integral treatment of S. enteritidis infections could be a viable option to replace the indiscriminate use of antibiotics.

The Impact of a Phytobiotic Mixture on Broiler Chicken Health and Meat Safety

The purpose of the study was to assess the effects of different doses of a phytobiotic mixture on selected production parameters and meat quality and to assess the residue of the preparation in tissues and the possible toxic effects in broiler chickens. Broiler chicks aged 160 days, divided into four equal groups, were supplemented with the phytobiotic mixture at different doses, D1-0.5 mL/L, D2-1 mL/L, and D3-2 mL/L, four times during a 42-day trial. There were no statistically significant differences in weight gain per week of life and mortality in the birds. The study also demonstrated that the use of the mixture of phytobiotics had no significant effect on colour, pH, WHC, and natural leakage. However, a beneficial effect of the additive was found in the group treated with a dose of 1 mL/L, where less thermal leakage from the meat was demonstrated. Furthermore, significant differences in the change in thigh muscle tenderness were also observed. In the histopathological analysis of the liver no significant differences were observed. In addition, no residues of the mixture or its metabolites were found in the tissues analysed. In conclusion, the proposed scheme of administration of the phytobiotic additive, regardless of the dose, does not cause pathological changes in organs and does not carry the risk of residues of the product in tissues intended for human consumption.

Luteolin: A Phytochemical to Mitigate S. Typhimurium Flagellin-Induced Inflammation in a Chicken In Vitro Hepatic Model

The use of natural feed supplements is an alternative tool to diminish the damage caused by certain bacteria, improving animal health and productivity. The present research aimed to investigate the proinflammatory effect of flagellin released from the bacterial flagellum of Salmonella enterica serovar Typhimurium and to attenuate the induced inflammation with luteolin as a plant-derived flavonoid on a chicken primary hepatocyte-non-parenchymal cell co-culture. Cells were cultured in a medium supplemented with 250 ng/mL flagellin and 4 or 16 µg/mL luteolin for 24 h. Cellular metabolic activity, lactate dehydrogenase (LDH) activity, interleukin-6, 8, 10 (IL-6, IL-8, IL-10), interferon-α, γ (IFN-α, IFN-γ), hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) concentrations were determined. Flagellin significantly increased the concentration of the proinflammatory cytokine IL-8 and the ratio of IFN-γ/IL-10, while it decreased the level of IL-10, indicating that the model served adequate to study inflammation in vitro. Luteolin treatment at 4 µg/mL did not prove to be cytotoxic, as reflected by metabolic activity and extracellular LDH activity, and significantly reduced the flagellin-triggered IL-8 release of the cultured cells. Further, it had a diminishing effect on the concentration of IFN-α, H₂O₂ and MDA and restored the level of IL-10 and the ratio of IFN-γ/IL-10 when applied in combination with flagellin. These results suggest that luteolin at lower concentrations may protect hepatic cells from an excessive inflammatory response and act as an antioxidant to attenuate oxidative damage.

Antibiotics in avian care and husbandry-status and alternative antimicrobials

Undoubtedly, the discovery of antibiotics was one of the greatest milestones in the treatment of human and animal diseases. Due to their over-use mainly as antibiotic growth promoters (AGP) in livestock farming, antimicrobial resistance has been reported with increasing intensity, especially in the last decades. In order to reduce the scale of this phenomenon, initially in the Scandinavian countries and then throughout the entire European Union, a total ban on the use of AGP was introduced, moreover, a significant limitation in the use of these feed additives is now observed almost all over the world. The withdrawal of AGP from widespread use has prompted investigators to search for alternative strategies to maintain and stabilize the composition of the gut microbiota. These strategies include substances that are used in an attempt to stimulate the growth and activity of symbiotic bacteria living in the digestive tract of animals, as well as living microorganisms capable of colonizing the host’s gastrointestinal tract, which can positively affect the composition of the intestinal microbiota by exerting a number of pro-health effects, i.e., prebiotics and probiotics, respectively. In this review we also focused on plants/herbs derived products that are collectively known as phytobiotic.

Evaluating Ruminal and Small Intestinal Morphology and Microbiota Composition of Calves Fed a Macleaya cordata Extract Preparation

The objective was to determine the impact of feeding MCE on ruminal and intestinal morphology and microbiota composition of calves. A total of 10 male and 10 female crossbred (dairy × beef) calves (6 d of age) were assigned randomly to control (CTL; n = 10) or MCE-supplemented (TRT; n = 10) groups. The MCE was fed in the milk replacer and top-dressed on the calf starter during pre-weaning (6 to 49 d) and post-weaning (50 to 95 d) periods, respectively. Calves were slaughtered at 95 d to collect rumen and intestinal samples to determine volatile fatty acid (VFA) profile, mucosal morphology, and microbiota composition. The effects of MCE were analyzed by accounting for the sex and breed effects. Feeding MCE increased rumen papillae length (p = 0.010) and intestinal villus height: crypt depth (p < 0.030) compared to CTL but did not affect rumen VFA profile. The TRT had a negligible impact on microbial community composition in both the rumen and the jejunum. In conclusion, feeding MCE from birth through weaning can improve ruminal and small intestinal mucosa development of calves despite the negligible microbiota composition changes observed post-weaning.

Impact of Supplementing Phytobiotics as a Substitute for Antibiotics in Broiler Chicken Feed on Growth Performance, Nutrient Digestibility, and Biochemical Parameters

To determine the level of application and the effectiveness of the use of plant feed additives from sweet chestnut wood extract (Castanea Sativa Mill) in the diet of Cobb-500 cross broiler chickens, four groups were formed via the balanced groups method. The chickens in the experimental groups were supplemented with sweet chestnut wood extract in the main diet rather than a feed antibiotic at an amount of 500 g per ton of compound starter feed and 250 g per ton of grower and finisher in the second experimental group; 650 g per ton of compound starter feed and 325 g per ton of grower and finisher in the third experimental group; and 800 g per ton of compound starter feed and 400 g per ton of grower and finisher in the fourth experimental group. Supplementation with phytobiotics led to an increase in the digestibility of the dry matter in the second and third groups compared to the first experimental group. Furthermore, broiler chickens supplemented with a medium dose of phytobiotics revealed a significant difference in both crude protein and fiber when compared to the second experimental group (91.95% and 12.11% vs. 88.98% and 10.07%, respectively). The preslaughter weight of the birds in the phytobiotics supplemented groups was higher than in those fed with the lowest dosage of phytobiotic by 5.47%, and the difference was significant. There were no significant differences in terms of the blood biochemical parameters between the groups. In summary, the inclusion of plant feed additives from sweet chestnut wood extract as a substitute for an antibacterial drug in the diet of broiler chickens did not deteriorate the blood biochemical parameters and improved the intensity of the nutrient digestion process. As a result, it enhanced the quality indicators of the broiler carcass during the entire growth period.

Effect of Phytobiotic Composition on Production Parameters, Oxidative Stress Markers and Myokine Levels in Blood and Pectoral Muscle of Broiler Chickens

Simple Summary

Intensive rearing of broiler chickens is accompanied with pathological processes occurring in muscle tissue that decrease meat quality. The application of common spices as feed additives for chickens may improve the birds’ health and prevent the development of myopathies. Therefore, the aim of the study was to examine the effect of the dietary level of a phytobiotic composition on the production parameters, oxidative stress markers and myokine levels in the blood and pectoral muscle of broiler chickens. The composition consisted of red pepper fruit, white mustard seed, soapwort root, calamus rhizome, and thymol, and it was tested at two levels, i.e., 60 and 100 mg/kg diet. The results showed that dietary supplementation with phytobiotic composition at the level of 100 mg/kg diet improved feed efficiency in broiler chickens and might improve the quality and economy of broiler meat production. The plant constituents exerted their beneficial effects on meat via decreasing tumor necrosis factor-α concentration in pectoral muscle and increasing interleukin-6 content in the blood of chickens.

Abstract

The aim of this study was to evaluate the effect of dietary level of a phytobiotic composition (PBC) on production parameters, oxidative stress markers and cytokine levels in the blood and breast muscle of broiler chickens. The experiment was performed on 48 one-day-old female Ross 308 broiler chickens divided into three groups (n = 16) fed the control diet (without PBC), and a diet supplemented with 60 or 100 mg/kg of PBC. After 35 days of feeding, blood and breast muscle samples were collected for analyses. There was no effect on final body weight and feed intake but PBC addition (100 mg/kg) improved feed efficiency as compared to the control. Also, this dietary level of PBC contributed to an increase in interlukin-6 content in blood and a reduction in tumor necrosis factor-α concentrations in pectoral muscle in comparison with the control group. In conclusion, the addition of 100 mg/kg PBC improved the production parameters of broiler chickens and beneficially influenced the regeneration and protection of pectoral muscle against pathophysiological processes that may occur during intensive rearing.

Recent developments in antimicrobial growth promoters in chicken health: Opportunities and challenges

With a continuously increasing human population is an increasing global demand for food. People in countries with a higher socioeconomic status tend to switch their preferences from grains to meat and high-value foods. Their preference for chicken as a source of protein has grown by 70% over the last three decades. Many studies have shown the role of feed in regulating the animal gut microbiome and its impact on host health. The microbiome absorbs nutrients, digests foods, induces a mucosal immune response, maintains homeostasis, and regulates bioactive metabolites. These metabolic activities are influenced by the microbiota and diet. An imbalance in microbiota affects host physiology and progressively causes disorders and diseases. With the use of antibiotics, a shift from dysbiosis with a higher density of pathogens to homeostasis can occur. However, the progressive use of higher doses of antibiotics proved harmful and resulted in the emergence of multidrug-resistant microbes. As a result, the use of antibiotics as feed additives has been banned. Researchers, regulatory authorities, and managers in the poultry industry have assessed the challenges associated with these restrictions. Research has sought to identify alternatives to antibiotic growth promoters for poultry that do not have any adverse effects. Modulating the host intestinal microbiome by regulating dietary factors is much easier than manipulating host genetics. Research efforts have led to the identification of feed additives, including bacteriocins, immunostimulants, organic acids, phytogenics, prebiotics, probiotics, phytoncides, and bacteriophages. In contrast to focusing on one or more of these alternative bioadditives, an improved feed conversion ratio with enhanced poultry products is possible by employing a combination of feed additives. This article may be helpful in future research towards developing a sustainable poultry industry through the use of the proposed alternatives.

In Vitro Evaluation of Antimicrobial Effect of Phytobiotics Mixture on Salmonella spp. Isolated from Chicken Broiler

Background: The identification of natural antibacterial agents from various sources that can act effectively against disease-causing foodborne bacteria is one of the major concerns throughout the world. In the present study, a unique phytobiotics mixture containing thymol, menthol, linalool, trans-anethole, methyl salicylate, 1,8-cineole, and p-cymene was evaluated for antibacterial activity against selected strains of Salmonella spp. Results: The phytobiotics mixture was effective against Salmonella enterica subsp. enterica serovars Enteritidis, Typhimurium, and Kentucky. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of this unique mixture for these three pathogens were 1:256. Among these three strains, one S. Kentucky presented the most extensive resistance profiles to 18 antibiotics belonging to 5 classes of antibiotics. One of S. Typhimurium presents extensive resistance profiles to 14 antibiotics belonging to 5 classes of antibiotics. Conclusions: The results suggest that the phytobiotics mixture used in the experiment can be used as a strong natural antibacterial agent against Gram-negative foodborne pathogens such as S. Typhimurium, S. Kentucky, and S. Enteritidis. This is a preliminary analysis of the effectiveness of a phytobiotic product in an in vitro model, which may be the starting point for further studies, including in vivo animal models.

Transcriptomic Analysis of the Spleen of Different Chicken Breeds Revealed the Differential Resistance of Salmonella Typhimurium

Salmonella Typhimurium (ST) is a foodborne pathogen that adversely affects the health of both animals and humans. Since poultry is a common source and carrier of the disease, controlling ST infection in chickens will have a protective impact on human health. In the current study, Beijing-You (BY) and Cobb chicks (5-day-old specific-pathogen-free) were orally challenged by 2.4 × 1012 CFU ST, spleen transcriptome was conducted 1 day post-infection (DPI) to identify gene markers and pathways related to the immune system. A total of 775 significant differentially expressed genes (DEGs) in comparisons between BY and Cobb were identified, including 498 upregulated and 277 downregulated genes (fold change ≥2.0, p < 0.05). Several immune response pathways against Salmonella were enriched, including natural killer-cell-mediated-cytotoxicity, cytokine−cytokine receptor interaction, antigen processing and presentation, phagosomes, and intestinal immune network for IgA production, for both BY and Cobb chickens. The BY chicks showed a robust response for clearance of bacterial load, immune response, and robust activation of phagosomes, resulting in ST resistance. These results confirmed that BY breed more resistance to ST challenge and will provide a better understanding of BY and Cobb chickens’ susceptibility and resistance to ST infection at the early stages of host immune response, which could expand the known intricacies of molecular mechanisms in chicken immunological responses against ST. Pathways induced by Salmonella infection may provide a novel approach to developing preventive and curative strategies for ST, and increase inherent resistance in animals through genetic selection.

Growth performance, carcass and meat quality, bone strength, and immune response of broilers fed low-calcium diets supplemented with marine mineral complex and phytase

Influence of marine mineral complex (CeltiCal) as a partial substitute for limestone on growth efficiency, carcass traits, meat quality, bone strength, calcium (Ca) retention, and immune response was investigated in broilers fed low-Ca diets with or without phytase (PHY) addition for a 35-d trial period. A total of 300 one-day-old Ross 308 straight-run broilers were randomly allocated to: T1 (positive control), recommended Ca levels + PHY; T2 (negative control), 0.2% below the recommended Ca levels + PHY; T3, 0.1% below the recommended Ca levels + 0.2% CeltiCal + PHY; T4, 0.2% below the recommended Ca levels + 0.4% CeltiCal + PHY; T5, 0.2% below the recommended Ca levels + 0.4% CeltiCal. PHY was added at 500 phytase units/kg diets. Each dietary treatment had 10 replications of 6 chicks each. Results revealed that production efficiency factor was greater for T4 compared to T2 and T5 during 22-35 d and for T1, T3, and T4 compared to T2 during 0 to 35 d (P < 0.05). Feed conversion ratio was lower for T3 and T4 compared to T2 and T5 during 0 to 35 d (P < 0.05). T4 had a greater (P < 0.05) dressing percentage than T2, which had a lighter (P < 0.01) small intestinal relative weight than all other treatments. Breast meat temperature at 15 min postmortem was highest for T1 and lowest for T3 (P < 0.001). Breast meat pH was greater for T1 compared to T5 at 15 min postmortem and for T3 compared to T4 at 24 h postmortem (P < 0.05). T5 had a lower breast meat redness than all other treatments at 15 min postmortem and then T1 and T3 at 24 h postmortem (P < 0.01). Tibia and femur weights were greater (P < 0.05) for T3, T4, and T5 compared to T2, which had the lowest tibia ash content (P < 0.05) and femur geometric properties (P < 0.001). Greater antibodies to infectious bronchitis virus (P < 0.01) and Ca retention (P < 0.001) were observed for T3 and T4 in comparison to T2. Based on the findings of this research, CeltiCal can adequately replace a considerable portion of limestone in broiler reduced-Ca diets containing PHY.

Allium-Based Phytobiotic for Laying Hens' Supplementation: Effects on Productivity, Egg Quality, and Fecal Microbiota

The poultry industry is constantly demanding novel strategies to improve the productivity and health status of hens, prioritizing those based on the holistic use of natural resources. This study aimed to assess the effects of an Allium-based phytobiotic on productivity, egg quality, and fecal microbiota of laying hens. One hundred and ninety-two 14-week-old Lohmann Lite LSL hens were allocated into an experimental farm, fed with a commercial concentrate with and without the Allium-based phytobiotic, and challenged against Salmonella. Productivity, egg quality, and fecal microbiota were monitored for 20 weeks. Results showed that the phytobiotic caused an increase on the number of eggs laid (p < 0.05) and in the feed conversion rate (p < 0.05); meanwhile, egg quality, expressed as egg weight, albumin height, haugh units, egg shell strength, and egg shell thickness remained unchanged (p > 0.05), although yolk color was decreased. Fecal microbiota structure was also modified, indicating a modulation of the gut microbiota by increasing the presence of Firmicutes and Bacteroidetes but reducing Proteobacteria and Actinobacteria phyla. Predicted changes in the functional profiles of fecal microbiota suggest alterations in metabolic activities that could be responsible for the improvement and maintenance of productivity and egg quality when the phytobiotic was supplemented; thus, Allium-based phytobiotic has a major impact on the performance of laying hens associated with a possible gut microbiota modulation.

Non-Antibiotics Strategies to Control Salmonella Infection in Poultry

Salmonella spp. is a facultative intracellular pathogen causing localized or systemic infections, involving economic and public health significance, and remains the leading pathogen of food safety concern worldwide, with poultry being the primary transmission vector. Antibiotics have been the main strategy for Salmonella control for many years, which has allowed producers to improve the growth and health of food-producing animals. However, the utilization of antibiotics has been reconsidered since bacterial pathogens have established and shared a variety of antibiotic resistance mechanisms that can quickly increase within microbial communities. The use of alternatives to antibiotics has been recommended and successfully applied in many countries, leading to the core aim of this review, focused on (1) describing the importance of Salmonella infection in poultry and the effects associated with the use of antibiotics for disease control; (2) discussing the use of feeding-based (prebiotics, probiotics, bacterial subproducts, phytobiotics) and non-feeding-based (bacteriophages, in ovo injection, vaccines) strategies in poultry production for Salmonella control; and (3) exploring the use of complementary strategies, highlighting those based on -omics tools, to assess the effects of using the available antibiotic-free alternatives and their role in lowering dependency on the existing antimicrobial substances to manage bacterial infections in poultry effectively.

Effect of the Eucalyptus viminalis leaf extract compound on the amino acid and fatty acid composition of broiler chicken meat

The article presents the results on evaluating the effect of the gamma-octalactone compound isolated from Eucalyptus viminalis leaf extract on the amino acid and fatty acid composition of protein and lipids of broiler chickens' muscle tissue. The object of the study was 7-day-old broiler chickens of the Arbor Acres cross. During the experiment, the control group poultry consumed the main diet (MD); the poultry of the experimental groups received the main diet plus gamma-octalactone at the following dose: group I – 0.05 ml/kg l.w./ day; II – 0.1 ml/kg l.w./ day; III – 0.2 ml/ kg l.w./day. It was found that the experimental compound's introduction into the diets significantly increases protein and fat content, as well as improves the balance of experimental groups' chicken meat for essential amino acids, as evidenced by a significant increase in the content of leucine and isoleucine - 2.27% (P≤0.01), valine - 0.8% (P≤0.05), phenylalanine 0.44 (P≤0.05) % in chickens of the experimental group III in relation to the control. With a relatively stable amount of saturated fatty acids in the experimental groups, compensation for insufficient synthesis of polyunsaturated fatty acids was observed by increased accumulation of monounsaturated fatty acids. However, despite the existing differences in the concentration of unsaturated fatty acids, no significant intergroup changes were observed.

Effects of Nano Emulsified Vegetable Oil and Betaine on Growth Traits and Meat Characteristics of Broiler Chickens Reared under Cyclic Heat Stress

The effects of nano-emulsified vegetable oil (NEVO) and betaine (BET) supplements on growth performance and meat qualities of broilers reared under cyclic heat stress (HS) were investigated. Two hundred and eighty-eight mixed-sex broilers at 21 d were randomly distributed to a 2 × 3 factorial arrangement of treatments formed by two environmental temperatures (thermoneutral (TN; 24 ± 1 °C) and cyclic high-temperature (HT; 35 ± 1 °C)) and three dietary treatments (control (CON), NEVO, and BET). The cumulative performance (21-35 d) revealed a reduction in average daily gain (ADG) (p < 0.05) in the CON compared to NEVO. NEVO and BET groups had a better feed conversion ratio (FCR) and performance efficiency factor (PEF) compared with the CON (p < 0.001, p < 0.01, respectively). The environmental temperature affected daily feed intake (DFI), ADG, FCR, and PEF. The addition of BET improved breast fillets yield, temperature, pH_15min, and pH_24hr (p < 0.05) in comparison with the CON. Moreover, the TN group had lower fillet temperature and higher pH_15min compared to the HT. Moreover, HT increased shear force (SF), hardness, springiness, cohesiveness, and chewiness of the fillets compared to TN. In conclusion, dietary supplementation with BET and NEVO could effectively improve performance parameters and meat characteristics under HS conditions.

Phytobiotics to improve health and production of broiler chickens: functions beyond the antioxidant activity

Phytobiotics, also known as phytochemicals or phytogenics, have a wide variety of biological activities and have recently emerged as alternatives to synthetic antibiotic growth promoters. Numerous studies have reported the growth-promoting effects of phytobiotics in chickens, but their precise mechanism of action is yet to be elucidated. Phytobiotics are traditionally known for their antioxidant activity. However, extensive investigations have shown that these compounds also have anti-inflammatory, antimicrobial, and transcription-modulating effects. Phytobiotics are non-nutritive constituents, and their bioavailability is low. Nonetheless, their beneficial effects have been observed in several tissues or organs. The health benefits of the ingestion of phytobiotics are attributed to their antioxidant activity. However, several studies have revealed that not all these benefits could be explained by the antioxidant effects alone. In this review, I focused on the bioavailability of phytobiotics and the possible mechanisms underlying their overall effects on intestinal barrier functions, inflammatory status, gut microbiota, systemic inflammation, and metabolism, rather than the specific effects of each compound. I also discuss the possible mechanisms by which phytobiotics contribute to growth promotion in chickens.