Effect of Housing System and Rosemary and Cinnamon Essential Oils on Layers Performance, Egg Quality, Haematological Traits, Blood Chemistry, Immunity, and Antioxidant

Rosmarinus officinalis L. essential oil enhances salt stress tolerance of durum wheat seedlings through ROS detoxification and stimulation of antioxidant defense

Salt-induced stress poses a significant barrier to agricultural productivity by impeding crop growth. Presently, environmentalists are dedicated to safeguarding food security by enhancing agricultural yields in challenging environments. Biostimulants play a crucial role in mitigating abiotic stresses in crop production, and among these, plant essential oils (EOs) stand out as organic substances with diverse biological effects on living organisms. Among the natural promoters of plant growth, Rosmarinus officinalis L. essential oil (RoEO) has gained considerable attention. Although the manifold effects of essential oils (EOs) on plant growth have been extensively demonstrated, their impact on salt stress tolerance in durum wheat seedlings remains unexplored. This investigation was undertaken to evaluate the biostimulatory capabilities of RoEO on the durum wheat cultivar "Mahmoudi." The effects of three RoEO concentrations (1, 2.5, and 5 ppm) on seed germination, growth establishment, and the induction of salt resistance under salinity conditions (150 mM NaCl) were tested. At 5 ppm, RoEO enhanced seedlings' tolerance to salinity by improving growth and reducing membrane deterioration and oxidative stress-induced damage. The expression profile analyses of seven stress-related genes (TdNHX1, TdSOS1, TdSOD, TdCAT, TdGA20-ox1, TdNRT2.1, and TdGS) using RT-qPCR showed enhancement of several important genes in durum wheat seedlings treated with 5 ppm RoEO, even under control conditions, which may be related to salt stress tolerance. The results indicate that the application of RoEO suggests a possible alternative strategy to increase salt tolerance in durum wheat seedlings towards better growth quality, thus increasing ROS scavenging and activation of antioxidant defense.

Essential oils as promising treatments for treating Candida albicans infections: research progress, mechanisms, and clinical applications

Candida albicans: (C. albicans) is a prevalent opportunistic pathogen that can cause severe mucosal and systemic fungal infections, leading to high morbidity and mortality rates. Traditional chemical drug treatments for C. albicans infection have limitations, including the potential for the development of drug resistance. Essential oils, which are secondary metabolites extracted from plants, have gained significant attention due to their antibacterial activity and intestinal regulatory effects. It makes them an ideal focus for eco-friendly antifungal research. This review was aimed to comprehensively evaluate the research progress, mechanisms, and clinical application prospects of essential oils in treating C. albicans infections through their antibacterial and intestinal regulatory effects. We delve into how essential oils exert antibacterial effects against C. albicans infections through these effects and provide a comprehensive analysis of related experimental studies and clinical trials. Additionally, we offer insights into the future application prospects of essential oils in antifungal therapy, aiming to provide new ideas and methods for the development of safer and more effective antifungal drugs. Through a systematic literature review and data analysis, we hope to provide insights supporting the application of essential oils in antifungal therapy while also contributing to the research and development of natural medicines. In the face of increasingly severe fungal infections, essential oils might emerge as a potent method in our arsenal, aiding in the effective protection of human and animal health.

A systematic review of potential productivity, egg quality, and animal welfare implications of extended lay cycles in commercial laying hens in Canada

Lay cycle lengths in the Canadian egg industry are currently 50 to 52 wk (68-70 wk of age). In light of increased productivity in commercial laying hens over the last few decades, the much longer lay cycle lengths already implemented in other countries, extending lay cycle lengths in Canada, should be considered with careful attention to potential environmental, economic, and animal welfare implications. However, there is a lack of information in the public domain that provides robust evidence of performance levels and potential trade-offs to support comprehensive consideration of the desirability of extending lay cycles beyond current Canadian norms. Hence, a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was undertaken. Data collection focused primarily on information related to feed-, flock management-, and hen genetics/physiology-related interventions that were studied in literature to support extension of lay cycles (review objective 1), and compiling and analyzing productivity, egg quality, and animal welfare outcomes reported at 70 wk of age or beyond (review objective 2). Several feed-related interventions such as high-protein diets, and probiotics supplements, and flock management interventions such split-feeding were found to potentially improve productivity, and especially egg quality, outcomes in the late laying phase. More studies with bigger flock sizes and in commercial lay facilities need to be undertaken before any of these interventions can be definitively recommended for commercial egg production. Under objective 2, productivity was found to be at acceptable levels well beyond 70 wk of age. Performance on most egg quality traits and animal welfare indicators were also at acceptable levels past 70 wk of age but increased variability was observed beyond ∼80 wk of age. There were also inconclusive indications on how hens in caged housing and white laying hens fare relative to hens in noncaged housing and brown-type layers during the late laying phase. Economic data were limited but suggested that lay cycle lengths beyond 90 wk might not generated net economic benefits.

Effects of Dietary Supplementation of Essential Oils, Lysozyme, and Vitamins' Blend on Layer Hen Performance, Viral Vaccinal Response, and Egg Quality Characteristics

Maintaining respiratory tract health is crucial for layers, impacting gut health, laying performance, and egg quality. Viral diseases and standard vaccinations can compromise tracheal epithelium function, leading to oxidative stress. This study assessed the impact of a blend of feed additives, predominantly lysozyme (L), essential oils (EO), and vitamins (VIT) (referred to as L + EO + VIT), on young layers during an oral vaccination schedule. The supplementation significantly enhanced antibody titers for Newcastle Disease Virus (NDV) and Infectious Bronchitis Virus (IBV) after vaccination, trachea functionality and intestinal health in the jejunum, increased egg production, and exhibited a trend toward higher egg weight. Although feed intake showed no significant difference, egg quality remained consistent across experimental groups. Moreover, L + EO + VIT supplementation elevated total phenolic content in eggs, improving oxidative stability in both fresh and stored eggs, particularly under iron-induced oxidation. Notably, it substantially reduced yolk lipid peroxidation and albumen protein carbonyls. In conclusion, water supplementation with L + EO + VIT may enhance humoral immune response to IBV and NDV, positively impacting hen productivity. These findings indicate improved tracheal function and enhanced oxidative stability, emphasizing the potential of this blend in promoting overall health and performance in layers.

Effects of essential oils on egg production and feed efficiency as influenced by laying hen breed: A meta-analysis

Background and Aim

Successful rearing of laying hens to achieve optimal egg production is an endeavor that often faces various constraints and challenges, such as infectious diseases, environmental stressors, and fluctuations in feed quality. The incorporation of essential oils (EOs) into the diet of laying hens has attracted considerable attention in recent years. Therefore, our study aimed to evaluate the efficacy of EO inclusion in laying hen diets by considering the effects of production phase and breed on performance, egg quality, serum biochemistry, gut health, and antioxidant activity.

Materials and Methods

The articles were obtained from the Web of Science, Scopus, Science Direct, and PubMed using the search terms "essential oils," "laying hens," and "phytobiotics." Data from 27 articles and 71 experiments were grouped according to laying hen production phase and breed in the database. The EO levels ranged from 0 to 1000 mg/kg, with thymol and carvacrol being the major EOs. A mixed model was used to analyze the data. Random effects were applied to the treatment, and fixed effects were applied to EO level, production phase, and breed.

Results

Egg production, feed intake, feed efficiency, eggshell quality, villus height, crypt depth, superoxide dismutase, and glutathione peroxidase levels increased linearly (p = 0.05) and egg weight and mass increased quadratically (p < 0.05) with increasing EO concentrations. An interaction was observed between the EO level egg production and feed conversion ratio (p = 0.05). Serum glucose, cholesterol, and malondialdehyde levels decreased with increasing EO concentrations (p < 0.05).

Conclusions

The inclusion of EOs effectively increased egg production, feed efficiency, egg weight, egg mass, eggshell quality, oxidative enzymes, and intestinal health. In addition, the proportion of dietary EOs in lightweight laying hens was higher than that in semi-heavy-weight laying hens in improving egg production and feeding efficiency.

Effects of housing systems and feed additive on growth, carcass traits, liver function, oxidative status, thyroid function, and immune parameters of broilers

The effects of rearing Cobb500 broiler chickens under 3 different housing systems (floor litter, floor plastic, and batteries) without or with feed additive (Butinov) on broiler performance, blood parameters and carcass traits were evaluated. Three hundred 1-day-old chicks were distributed in a 3 × 2 factorial arrangement (6 treatments each of 5 replicates). The results showed that reared broilers on litter or plastic floors had high values (P ≤ 0.01) of bird's weight (BW), weight gain (WG), and feed intake (FI) throughout the entire study period (1-42 d of age) compared with rearing on batteries. Rearing broilers in the different housing systems and with or without feed additives did not affect (P ≥ 0.05) total feed conversion (FCR). Different rearing systems or feed additives did not influence broiler chicks' carcass traits and some serum blood parameters. The plastic floor system significantly increased (P ≤ 0.05) blood serum corticosterone compared with litter and batteries. Feed additive (Butinov) decreased the level of T4 (P ≤ 0.05) in blood serum. Plastic floors or batteries significantly increased (P ≤ 0.01) the level of antibody titer against avian influenza virus (HIAV) compared to chicken reared on a litter floor. The results suggested that using housing systems of litter or plastic floors could improve broiler growth performance without adversely affecting carcass traits and blood characteristics compared with rearing in batteries. Also, broiler diets' feed additive (Butinov) and their interaction with rearing systems did not improve broiler growth performance.

Effect of rosemary (Rosmarinus officinalis) leaf meal supplementation on production performance and egg quality of laying hens

This experiment was conducted to investigate the supplemental effect of rosemary leaf meal (RLM) on egg production and egg quality in Lohmann-Brown laying hens. For each treatment, six replicates were performed with four 24-week-old laying hens for a total of 96 chickens. Dried rosemary leaf meal (RLM) was present in the commercial laying hen ration at 0, 1.7, 3.5 and 5.2%, respectively. The interactions between dietary treatments, egg storage temperatures (4 °C, 21.5 °C), and egg storage durations (7, 14, 21, 28, and 35 days) were examined in factorial designs using a fully randomized design. The data were analyzed using the Statistical Analysis System (SAS, 2014, Ver. 9.3) and Tukey's multiple range tests to separate the means. The inclusion of dried RLM at a level of 5.2% (p < 0.05) significantly improved the hens' daily egg production (78.9%). Feed conversion ratio (2.25) and egg weight (56.7 g) compared to control treatment. Similarly, at 3.5% and 5.2% RLM supplementation, eggshell weight (5.876 g) and eggshell strength increased significantly (p < 0.05) (compared to control, a weight of 3.76 kg/cm2 and a shell thickness (0.37 mm) was observed. In addition, the groups fed 5.2% RLM had significantly higher albumin weight (34.9 g/L), albumin height (6.9 mm), and yolk weight (15.6 g/L). l), yolk height (15.9 mm), yolk color (5.3 points), and Hough unit (83.9 points) than the control groups. Regarding the external characteristics of stored eggs, a group of hens fed at rates of 3.5 and 5.2% RLM showed significantly greater (p < 0.05) egg weight with increases in storage temperature and duration as a control group. There was a significant interaction effect between stored eggs collected from the supplemented groups in terms of egg weight, weight loss, shell weight, shell strength, and shell thickness stored at specific temperatures and storage durations. There was a decrease in albumen level and Haugh unit (HU) with an increase in storage temperature and duration over treatment (P < 0.05). Therefore, better external quality was observed in eggs collected from a group of chickens fed 4.5 and 5.2% RLM after 35 days of storage compared to a control group. Mean albumen height, albumen weight, HU, yolk height, and yolk color of eggs stored in the refrigerator (4 °C) were an exception for yolk weight, which was higher compared to room temperature (21.5 °C). Significantly low (P < 0.05) albumen height (6.61 to 2.96 cm), Hough unit (82.49 to 47.64 points), and yolk height (14.66 to 12.35 mm) were observed at 35 days storage recorded in the control group. In conclusion, supplementation with RLM at 3.5% and 5.2% improved the performance and quality of both fresh and stored eggs.

Plectranthus amboinicus and rosemary (Rosmarinus officinalis L.) essential oils effects on performance, antioxidant activity, intestinal health, immune response, and plasma biochemistry in broiler chickens

This work aimed to assess the effects of Plectranthus amboinicus essential oil (PAE) and rosemary (Rosmarinus officinalis L.) essential oil (ROE) as feed additives on performance, antioxidant activity, intestinal microbiota, intestinal morphology, immune response, and plasma biochemistry using 320 unsexed 1-day-old Ross 308 broiler chickens. The chickens were assigned randomly into four treatments containing eight replicates with 10 chickens each. Treatment diets included a basal diet as a control group, 100 mg/kg PAE, 200 mg/kg PAE, and 100 mg/kg ROE. ROE affected the growth performance in the starter phase by improving (p = .01) the feed conversion ratio (FCR) compared with the control diet. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity in the plasma were elevated (p < .0001) by both feed additives. Supplementation of additives could increase (p < .006) total antioxidant capacity (TAC). Furthermore, malondialdehyde (MDA) values in the breast (p < .0001) and thigh (p < .001) for all supplemented diets were less than the control group. The essential oils (EOs) reduced (p < .005) coliform counts in the ileum and increased (p = .029) lactic acid bacteria counts. In addition, villus height (VH) and crypt depth (CD) increased, whereas the density of goblet cells decreased in the small intestine when feed additives were included. Also, the antibody titers against sheep red blood cells (SRBC) and Newcastle disease virus (NDV) were increased (p < .0001) by EOs. Plasma total protein (p = .04) and globulin (p = .02) were increased, and cholesterol was reduced (p = .002) by supplemented diets. Our study revealed that PAE could effectively improve the antioxidant activity, intestinal microbiota population, intestinal morphology, immune response, and plasma biochemistry parameters in broiler chickens.

Effect of increasing levels of Leucaena leucocephala seeds to grass pellets on performance of grower rabbits

The study was carried out to determine the chemical composition of composite pellets of Megathyrsus maximus containing Leucaena leucocephala seed meal at the varying level and growth responses, as well as haematological and serum biochemical of rabbits, fed the pellets for 60 days. The treatment consists of M. maximus and L. leucocephala-100:0, 90:10, 80:20, 70:30 and 60:40, respectively. Results revealed an increase (P < 0.05) in the proximate composition of the grass pellets with an increase in seed inclusion while there was a reduction (P < 0.05) in the NDF contents of the pellets. An increase in the tannin contents was recorded with an increase in seed inclusion to the grass pellets. Rabbits fed with 30 and 40% inclusions of seed in the grass pellets had similar weight gain while the lowest feed conversion ratio was recorded in rabbits fed grass with 30% seed inclusion. Packed cell volume, RBC and lymphocyte in rabbits were altered with feeding grass seed pellet (P < 0.05), although no particular pattern was followed. Total protein, globulin and urea contents were reduced in the rabbits as the contents of the seeds in the grass pellets increased. Albumin contents in pellets with 30% of seeds were higher in the rabbits fed the pellets above other treatments. It can be concluded that increasing the seed meal level up to 30% in grass pellets supported growth response without inflicting any side effects on the health indices of the rabbits.

The Effect of In Ovo Administration of Rosemary Essential Oil on Hatchability, Relative Hatching Weight, and Embryo Mortality Rate in Japanese Quail (Coturnix coturnix japonica)

This study aimed to determine the effects of air sac injection of rosemary essential oil at different concentrations in ovo in quail eggs on hatching rate, relative chick weight at hatching, and embryonic mortality rate. A total of 1060 Japanese quail eggs were divided into four groups: negative control (non-injected), positive control (30 µL sterile distilled water/egg), and two treated groups with 1 and 3 µL oil/egg, respectively. The concentration of 3 µL/egg showed a toxic effect on embryonic development, as revealed by the significantly (p = 0.015) higher post-injection mortality rate (18.21%) compared to 1 µL/egg with 8.3%. Furthermore, hatchability was significantly increased (p = 0.0001) with 1 µL/egg compared to 3 µL/egg with 69.1% and 44.48%, respectively. No significant difference was observed between the concentration of 1 µL/egg and the control groups (p = 0.822). Both l and 3 µL essential oil/egg significantly enhanced (p = 0.0001) relative chick weight at hatching by 67.14% and 70.32%, respectively, compared to the control groups. In conclusion, injecting eggs with 1 µL oil/egg showed positive effects both on hatching and relative chick weight. The concentration of 3 µL/egg was revealed to be toxic, with dramatic effects on embryonic survival.

Application of botanical products as nutraceutical feed additives for improving poultry health and production

Poultry is one of the most consumed sources of animal protein around the world. To meet the global demands for poultry meat and eggs, it is necessary to improve their nutrition to sustain the poultry industry. However, the poultry industry faces several challenges, including feedstuff availability, the banning of antibiotics as growth promoters, and several environmental stressors. Therefore, there is a critical need to include available nutraceuticals in the diet to sustain the poultry industry. Nutraceuticals are natural chemical substances that positively influence animal physiological and productive traits. Botanical products (such as fenugreek seeds, ginger roots, and olive leaves) are among the most commonly used nutraceuticals and are gradually gaining popularity in the poultry industry due to their immense benefits in nutrition and therapeutic properties. They can be added to the diet separately or in combination (as a natural antioxidant and immunostimulant) to improve poultry health and production. Botanical products are rich in essential oils and essential fatty acids, which have multiple benefits on the animal's digestive system, such as activating the digestive enzymes and restoring microbiota balance, enhancing poultry health, and production. These nutraceuticals have been shown to stimulate the expression of several genes related to growth, metabolism, and immunity. In addition, the essential oil supplementation in poultry diets up-regulated the expression of some crucial genes associated with nutrient transportation (such as glucose transporter-2 and sodium-glucose cotransporter-1). Previous studies have suggested that supplementation of botanical compounds increased broiler body weight and hen egg production by approximately 7% and 15%, respectively. Furthermore, the supplementation of botanical compounds enhanced the reproductive efficiency of hens and the semen quality of roosters by 13%. This review article discusses the significant effects of some botanical products in the poultry industry and how they can benefit poultry, especially in light of the ban on antibiotics as growth promoters.

Essential oils as valuable feed additive: A narrative review of the state of knowledge about their beneficial health applications and enhancement of production performances in poultry

New research has begun to develop safe and effective alternatives to feed-antibiotics as growth enhancers in response to mounting pressure on the poultry sector to do so. There is a significant demand for poultry products all across the world right now. To achieve this goal, key performance indicators are optimized, such as the rate of chicken growth, the amount of feed used, and the health of the flock as a whole. As a result of this growing need, various alternatives to antibiotics have entered the market. New approaches are desperately needed to keep poultry productivity and efficiency at a high level in the face of mounting pressure to limit the use of antibiotics. Recent years have seen an uptick in interest in the potential of aromatic plant extracts as growth and health boosters in poultry. The great majority of plants' positive effects are accounted for by essential oils (EOs) and other secondary metabolites. EOs have been proven to promote digestive secretion production, improve blood circulation, exert antioxidant qualities, reduce levels of dangerous microbes, and maybe improve the immune status of poultry. EOs are often believed to be safe, non-toxic alternatives because they are all-natural, chemical-free, and devoid of potentially harmful deposits. EOs are extracted from plants, and while there are thousands of them, only approximately 300 have been deemed to have significant commercial value. Many different types of bacteria, viruses, fungi, and parasites are negatively affected by EOs in multiple studies conducted both in vitro and in vivo. The review covers the fundamentals of EOs, their anti-oxidant and immunomodulatory capabilities, their growth-promoting benefits, and their effectiveness against numerous diseases in poultry.

Origanum dubium (Cypriot Oregano) as a Promising Sanitizing Agent against Salmonella enterica and Listeria monocytogenes on Tomato and Cucumber Fruits

In recent years, the use of natural products such as essential oils (EOs) and other plant extracts for the preservation of fresh produce has attracted much interest from the food industry. Many endemic medicinal and aromatic plants, such as Cypriot oregano (Origanum dubium), present a plethora of properties that can be utilized by the fruit and vegetable sectors of the food industry. The purpose of the present study was to assess the effects of O. dubium EO and hydrosol (at different concentrations and durations of dipping application) for the preservation of tomato and cucumber fruit quality, and their effectiveness as sanitizing agents against two foodborne pathogens (Listeria monocytogenes and Salmonella enterica). The results of this study indicated that increased concentrations of EO, combined with a longer duration of application, resulted in less marketable fruit compared to hydrosol application. Interestingly, EO application at lower concentrations and shorter durations of application (i.e., 0.01% for 5 min) increased fruit antioxidant, ascorbic acid and carotenoid levels (for tomato fruit), suggesting an increase in the nutritional value of the treated fruit, compared to the control. EO and hydrosol were able to decrease the bacterial populations (both bacteria) on fruits. Both products were especially effective against L. monocytogenes, even seven days after their application and storage at 11 °C (up to an approx. 3 log reduction with the EO application). Overall, the results of this study suggest that the use of O. dubium EO and hydrosol could be considered as alternative sanitation means for tomatoes and cucumbers.

Use of Cinnamon and its Derivatives in Poultry Nutrition

The recent trend toward banning the use of antibiotics in poultry feed as a growth promoter directs the scientific community to look for natural alternatives with potential growth-promoting and immunomodulating properties. Phytogenic feed additives have attracted significant attention as alternatives to antibiotics to improve growth performance and enhance immune responses. They have anti-inflammatory, antioxidant, antiviral, and antifungal properties, depending on their chemical structure and composition. Scientists are using these non-conventional ingredients as feed additives in the form of oil or powder. Essential oils (EO) are volatile liquids produced from aromatic plants. Their application has gained momentum in controlling cholesterol as free radical scavengers, anti-microbials, antifungals, and stimulants of digestive enzymes. EO's possible antimicrobial features against harmful pathogens are primarily associated with the high content of volatile components in oils. The current chapter highlights the beneficial impact of cinnamon oil as a feed additive on poultry growth performance, meat quality, carcass traits, and its hypo-cholesterolaemic impact, antioxidant act, microbiological aspects, and immunomodulatory effects.

Advanced Practical Strategies to Enhance Table Egg Production

The global demand for table eggs has increased exponentially due to the growing human population. To meet this demand, major advances in hen genetics, nutrition, and husbandry procedures are required. Developing cost-effective and practically applicable strategies to improve egg production and quality is necessary for the development of egg industry worldwide. Consumers have shown a strong desire regarding the improvement of hens' welfare and egg quality. They also become interested in functional and designer foods. Modifications in the nutritional composition of laying hen diets significantly impact egg nutritional composition and quality preservation. According to previous scientific research, enriched egg products can benefit human health. However, producers are facing a serious challenge in optimizing breeding, housing, and dietary strategies to ensure hen health and high product quality. This review discussed several practical strategies to increase egg production, quality, and hens' welfare. These practical strategies can potentially be used in layer farms for sustainable egg production. One of these strategies is the transition from conventional to enriched or cage-free production systems, thereby improving bird behavior and welfare. In addition, widely use of plant/herbal substances as dietary supplements in layers' diets positively impacts hens' physiological, productive, reproductive, and immunological performances.

Inhibition of Essential Oils on Growth of Aspergillus flavus and Aflatoxin B1 Production in Broth and Poultry Feed

Aflatoxin B1 (AFB1), a common contaminant in food and feed during storage, does great harm to human and animal health. Five essential oils (thymol, carvacrol, cinnamaldehyde, eugenol, and citral) were tested for their inhibition effect against Aspergillus flavus (A. flavus) in broth and feed. Cinnamaldehyde and citral were proven to be most effective against A. flavus compared to others and have a synergistic effect when used simultaneously. The broth supplemented with cinnamaldehyde and citral was inoculated with A. flavus (106 CFU/mL) by using the checkerboard method, and mold counts and AFB1 production were tested on days 0, 1, 3, and 5. Similarly, 100 g poultry feed supplemented with the mixture of cinnamaldehyde and citral at the ratio 1:1 was also inoculated with A. flavus, and the same parameters were tested on days 0, 7, 14, and 21. In poultry feed, cinnamaldehyde and citral significantly reduced mold counts and AFB1 concentrations (p < 0.05). Results showed that cinnamaldehyde and citral have a positive synergy effect and could both inhibit at least 90% the fungal growth and aflatoxin B1 production at 40 μg/mL in broth and poultry feed, and could be an alternative to control aflatoxin contamination in food and feed in future.

The Impact of Paulownia Leaves Extract on Performance, Blood Biochemical, Antioxidant, Immunological Indices, and Related Gene Expression of Broilers

The current research sought to assess the effects of paulownia leaves extract (PLE) on performance, blood hematological, antioxidant activity, and immunological response of broiler chicken. In total, two hundred 1-day-old male Cobb⁵⁰⁰ chicks were allocated randomly into four equal treatments with 5 replicates. The first treatment served as a control (CNT) and was fed the basal diet only, while the other treated treatments were fed on the basal diet supplemented with 0.1, 0.3, and 0.5 g/kg diet of PLE, respectively. The performance results showed significant increments (P < 0.05) in live body weight (LBW), weight gain (WG), and European production efficiency factors (EPEIs) (linearly; p < 0.001) in cooperated with increasing PLE levels in broiler diets. At the same time, feed conversion ratio (FCR) and livability percentages were numerically enhanced under the effects of PLE supplementation. Moreover, a notable increase (P < 0.05 or 0.01) in oxidative remarks activity (GSH, glutathione; SOD, super oxide-dismutase and CAT, catalase) and elevated levels of immunoglobulin (IgM, immunoglobulin M and IgG, immunoglobulin G) were noted (P < 0.05) for treatments fed with PLE in a dose-dependent manner. Also, a dramatic linear increase was observed in mRNA expression of IGF-1, GHR, IL-1β, and IL-10 genes of broiler chickens. This study concluded that enriched broiler feeds with 0.5 g/kg PLE might be a beneficial strategy to promote broiler health and production.

Anti-proliferative and immunomodulatory potencies of cinnamon oil on Ehrlich ascites carcinoma bearing mice

Cinnamon is a well-known natural spice and flavoring substance used worldwide. The objective of the present work is to explore the possible antitumor and immunomodulatory potencies of cinnamon essential oil (Cinn) on Ehrlich ascites carcinoma (EAC). A total of fifty female Swiss albino mice were sub-grouped into five groups (n = 10), namely, normal (a non-tumorized and non-treated) group; EAC-tumorized and non-treated group; Cinn (non-tumorized mice received Cinn, 50 mg/kg per body weight daily) group; a group of EAC-tumorized mice treated with Cinn and the final positive control group of EAC-tumorized mice received cisplatin. Eight compounds were identified from Cinn using UPLC-MS-Qtof and NMR analysis. Compared to EAC untreated group, Cinn successfully (P < 0.05) inhibited tumor growth by reducing tumor cell count (45%), viability (53%) and, proliferation accompanied by the inhibition of tumor growth rate. Moreover, a significant (P < 0.05) arrest in the cell cycle at G₀/G₁ phase was noticed following Cinn treatments (~ 24.5%) compared to EAC group. Moreover, Cinn markedly evoked an antitumor immune response by elevating the percentage of splenic T helper (CD3⁺CD4⁺) and T cytotoxic (CD3⁺CD8⁺) cells. It is noteworthy that Cinn treatments significantly restored different hematological alterations as well as liver and kidney functions in EAC-tumorized mice. In conclusion, results suggest that Cinn has a good antitumor and immunostimulatory potencies against Ehrlich ascites carcinoma in vivo. The mechanism underlying its antitumor activity may be attributed to its immunostimulatory effects which increase its potential as a promising anticancer candidate.

Minthostachys verticillata Griseb (Epling.) (Lamiaceae) essential oil orally administered modulates gastrointestinal immunological and oxidative parameters in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Minthostachys verticillata (Griseb.) Epling (Lamiaceae) is a plant used in folk medicine for digestive or respiratory disorders. In addition, it is incorporated as condiment, in foods, as beverage flavoring or mate. The ethnopharmacological interest of M. verticillata resides in its essential oil (EO). Part of group has demonstrated the immunomodulatory ability of EO giving this oil a biological potential not known until that moment and conducted studies to evaluate their possible application in diseases of veterinary interest. However, the immunomodulatory effects of EO administered orally have not been fully characterized.

AIM OF THE STUDY

This study evaluated the impact of EO oral administration on gastrointestinal and immune health through measurement of immunological and oxidative parameters in mice.

MATERIAL AND METHODS

The EO was extracted from the leaves, slender stems and flowers of M. verticillata by hydrodistillation and chemical analyzed by gas chromatography-mass spectrometry (GC-MS). Prior to in vivo study, the cytotoxic effect of EO was determined using the human colon carcinoma Caco-2 cell line. For in vivo study, three groups of male Balb/c mice (n = 3) were orally administered with saline solution (control group) and EO (5 or 10 mg/kg/day) during 10 consecutive days. Subsequently, histological and hematological parameters, cytokines production, oxidative markers and CD4⁺ and CD8⁺ T cells were evaluated.

RESULTS

The chemical analysis of EO revealed the presence of a high content of monoterpenes, being the main pulegone (76.12%) and menthone (14.28%). The EO oral administration improved mice growth performance and modulated systemic adaptive immune response by increasing in the total leukocyte number. A high percentage of CD4⁺ T cells were observed whereas the number of CD8⁺ T cells was not altered. EO did not alter the morpho-physiology of intestine and improved total antioxidant capacity by decreasing MDA concentrations. In addition, EO decreased the IL-6 levels and increased in the IL-4 and IL-10 concentrations.

CONCLUSION

Results indicate that M. verticillata EO modulate inflammatory and oxidative parameters constituting a natural alternative which could be applied to improve gastrointestinal and immune functionality in animals.

Evaluating the Nutritional and Immune Potentiating Characteristics of Unfermented and Fermented Turmeric Camel Milk in Cyclophosphamide-Induced Immunosuppression in Rats

Antioxidative, nutritional, and immune-boosting characteristics of turmeric-camel milk (TCM) and fermented turmeric-camel milk (FTCM) were investigated. A cyclophosphamide-induced immunosuppression rat model consisting of six experimental groups was carried out to study the effects of TCM and FTCM on weight gain, antioxidant status, immunoglobulin (Igs), pro-inflammatory and anti-inflammatory cytokines, and oxidative stress biomarkers. TCM or FTCM were orally administrated at 10 or 20 mL Kg^-1 rat weight to CYP-immunosuppressed rats for 2 weeks in the presence of negative (NR) and positive (CYP) control groups. The phytochemical analysis and antioxidant capacity results indicated that TCM and FTCM contained considerable phenolic content with super antioxidant activities. CYP injection affected the rats' weight directly during the first week and then, a low weight gain percentage was recorded in treated groups at the end of the experiment. The most efficient treatment for recovering rats' weight was administering TCM and FTCM at 20 mL kg^-1. Feed efficiency significantly increased with feeding TCM and FTCM in a dose-dependent manner. A significant improvement was found in WBCs, lymphocytes, and neutrophils count, suggesting that both TCM and FTCM alleviated the CYP-induced immunity suppression in a dose-dependent manner. IgG, IgA, and IgM concentrations in the CYP + TCM at 10 or 20 mL kg^-1 and CYP + FTCM at 10 or 20 mL kg^-1 groups were increased significantly. Concentrations of IL-1 beta, IL-6, IL-10, IL-13, and IL-TNF-α in the CYP group were significantly lower than in the NR group. Interestingly, both TCM and FTCM, especially with high doses, significantly enhanced cytokines production. Administrating FTCM was more potent than TCM, indicating that TCM with probiotics fermentation potentiated the immunological activity in immunosuppressed rats. Treated rats with TCM and FTCM can reverse CYP inhibition of antioxidant enzyme activities, significantly increase GSH, CAT, and SOD, and decrease MDA levels in a dose-dependent manner. In conclusion, these observations indicated that FTCM exhibits better improvements in weight gain, increased immune biomarkers in terms of WBCs, enhanced pro-inflammation and anti-inflammation responses, and accelerated antioxidant activity in immunosuppressed rats compared with TCM. It could be beneficial and profitable for boosting immunity and protecting against oxidative stress.

Changes in Fatty Acids Profile, Health Indices, and Physical Characteristics of Organic Eggs from Laying Hens at the Beginning of the First and Second Laying Cycles

The present study compared the fatty acid profile and some physical parameters of eggs from hens reared according to the organic system at the beginning of the first and second laying cycle. A total of 1080 eggs were analysed at the beginning of the first (from the 28th to 30th week of age) and the second (from the 78th to 80th week of age) laying cycle. It was found that the hen ages influenced the egg weight, egg surface area, yolk proportion, and eggshell colour. Albumen and eggshell proportion, albumen, yolk index, Haugh unit score, and eggshell strength were lower in eggs from older hens compared with those produced from younger layers. Monounsaturated fatty acids were found in higher amounts than saturated fatty acids and polyunsaturated fatty acids in egg yolks of eggs from layers only at the beginning of the second laying cycle. The PUFAn-6/n-3 ratio, saturation, atherogenic, and thrombogenic indices were significantly lower in the egg yolks from older hens compared to younger layers. These findings (regarding the eggs from the older ones) prove that it is practical to utilize them in the organic farming system during a period of two years.

Effects of essential oil/palygorskite composite on performance, egg quality, plasma biochemistry, oxidation status, immune response and intestinal morphology of laying hens

The current study aimed to assess the effects of different levels of essential oil/palygorskite composite (EO-PGS) supplementation on performance, egg quality, oxidative status, immunity and intestinal morphology of laying hens. A total of 480 laying hens aged 65 wk were randomly assigned into 4 groups (6 replicates of 20 hens each). Hens were fed the basal diet supplemented with 0 (control diet), 0.5, 0.75 or 1.0 g/kg EO-PGS for 56 d. Data were analyzed by One-way ANOVA. Results showed that birds fed with diet supplemented with EO-PGS had increased the egg production (P < 0.05) more than birds fed with control diet. The yolk index and shell thickness were increased in 0.75 and 1.0 g/kg EO-PGS groups at d56 (P < 0.05). There was no significant difference in plasma biochemical parameters among all groups. Compared with the control group, supplementation of EO-PGS increased the immunoglobulin-G and interleukin-2 levels in plasma (P < 0.05). The total antioxidant capacity in plasma and liver, the plasma catalase concentration, the activity of total superoxide dismutase in the liver and the activity of glutathione peroxidase in the spleen were increased in the EO-PGS groups (P < 0.05). The concentration of malondialdehyde in the liver was decreased with the increasing level of EO-PGS (P < 0.05). The crypt depth of ileum and duodenum of birds fed with EO-PGS supplemented diet had a tendency to decrease (0.05<P < 0.1) and the villus height to crypt depth ratio of ileum increased (P < 0.05), compared with birds fed with control diet. In summary, EO-PGS supplementation improved the egg production, enhanced antioxidation and immune functions, and ameliorated egg quality and intestinal morphology of laying hens, and a level of 0.75 g/kg EO-PGS was recommended in laying hens diets.

Impacts of tea tree or lemongrass essential oils supplementation on growth, immunity, carcass traits, and blood biochemical parameters of broilers reared under different stocking densities

The effects of tea tree essential oil (TTEO) and lemongrass essential oil (LGEO) with different stocking densities on the growth performance, biochemical markers, antioxidants, and immunity state of broiler chickens were studied.  Birds were housed at stocking densities of 25, 30, 35, and 40 kg/m². The treatments were, basal diet without any supplementation, the second and third groups were supplemented with 300 mg TTEO/kg feed, and 300 mg LGEO/kg feed, respectively. Results revealed that increasing stocking density from 25 to 40 kg/m² significantly reduced body weight and daily weight gain at different ages. The phagocytic index and activity were significantly higher under the lower stocking density (25 kg/m²). Serum amyloid A (SAA), serum or liver transferrin (TRF), or C-reactive protein (CRP) were significant decreased when decreasing stocking density. Increasing stocking density from 25 to 40 kg/m² resulted in a significant increase in the serum urea, creatinine, uric acid, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), and catalase (CAT) levels. However, there was a significant reduction in antioxidant enzyme activity, including glutathione peroxidase (GPx) and superoxide dismutase (SOD), as stocking density increased. The supplementation of TTEO produced significantly higher body weight and daily weight gain followed by LGEO. Additionally, the mortality rates were reduced in TTEO (27.4%) and LGEO (25%) groups. TTEO or LGEO supplementation significantly improved meat constituents and cellular immunity and reduced serum total lipids, serum and meat cholesterol, and triglycerides, SAA, TRF, and CRP. For all these measured parameters, superior results were obtained when TTEO was used compared to LGEO. TTEO or LGEO supplementation also significantly reduced serum urea, creatinine, uric acid, and the enzymatic activities of LDH, ALT, AST, MDA, and CAT (but not GPx and SOD) in comparison to the control treatment. Overall, our results showed the superiority of TTEO over LGEO as a feed supplement in broiler diets. In conclusion, TTEO treatment offers a better solution for raising broiler chickens in high stocking density.

Impact of varying housing systems on egg quality characteristics, fatty acid profile, and cholesterol content of Rhode Island Red × Fyoumi laying hens

The present study was designed to study the effects of conventional and free range systems on egg quality attributes, fatty acid profile, and cholesterol contents of laying hen. Two hundred and forty R1 cross of Rhode Island Red (RIR) × Fyoumi (F) layers during the peak production were divided into two groups and reared in two different housing systems (free range vs. conventional systems). The statistical analysis of the results revealed that the housing system (modification of diet) significantly (p < 0.05) affected egg quality, fatty acid profile, and cholesterol contents. The highest (p < 0.05) whole egg and albumen weights were recorded for eggs produced in a conventional system and higher yolk weight and shell thickness were recorded in free range hens. Significantly (p < 0.05) lower concentration of saturated and higher concentration of mono- and polyunsaturated fatty acids were observed in eggs produced under a free range system. In addition, higher level of total omega-3 fatty acids and higher ratio of omega-6 to omega-3 fatty acids were observed in free range eggs as compared to those in the conventional system. From the results of the present study, we concluded that eggs produced from Rhode Island Red × Fyoumi laying hens in a free range system are qualitatively superior compared to those in the conventional system.

Dietary encapsulated essential oil mixture influence on apparent nutrient digestibility, serum metabolic profile, lymphocyte histochemistry and intestinal morphology of laying hens

Objective

The study aimed to evaluate the effects of a mixture of encapsulated essential oils (EOs) addition on nutrient digestion, serum biochemical parameters, peripheral blood alpha-naphthyl acetate esterase (ANAE), and acid phosphatase (ACP-ase) positive lymphocyte ratios and intestinal morphology in laying hens.

Methods

A total of 320 laying hens of 48-wk-old were randomly allotted into 4 treatment groups with 10 replicates of 8 birds in each replicate. The birds were fed a basal diet (control) or the diet added with mixture of EOs (which consist of eugenol, nerolidol, piperine, thymol, linalool, and geraniol) at 50, 100, and 200 mg/kg for period of 84 days.

Results

The addition of EOs at 100 or 200 mg/kg increased the dry matter, organic matter, and crude protein digestion as compared to control. The addition of all doses of EOs did not affect serum gamma glutamyl transferase, alanine aminotransferase, and P but increased serum asparate aminotransferase (AST) concentration. The addition of 200 mg/kg EOs increased serum creatinine, while 100 mg/kg decreased Ca concentration. The addition of 100 and 200 mg/kg EOs generally improved ANAE and ACP-ase positive peripheral blood lymphocyte ratios and intestinal morphology.

Conclusion

It can be concluded that, the addition of 100 or 200 mg/kg encapsulated EOs generally increased apparent nutrient digestion and serum AST concentration, improved ANAE and ACP-ase positive peripheral blood lymphocytes and intestinal morphology in laying hens.

The use of some plant-derived products as effective alternatives to antibiotic growth promoters in organic poultry production: a review

Improving poultry production, increasing poultry immunity, and reducing the disease spreading can be achieved by adding various potentially valuable ingredients to the feed or drinking water of poultry flocks. Because of the emergence of antimicrobial resistance, antibiotic growth promoters (AGP) in animal nutrition were prohibited. Additionally, consumer preferences tend towards purchasing products from livestock raised without antibiotics. Therefore, there is a critical need to find effective growth promoter alternatives and treatment methods for common poultry diseases. Some spice plants play important roles in improving the taste, aroma, and color of human food and their positive effects on human and animal health. The current review aimed to provide a broader perspective on some spice crops which can be effective alternatives to antibiotics in organic poultry production. These spices were including Thymus vulgaris, Cichorium intybus, Coriandrum sativum, Aloe vera, Heracleum persicum, Curcuma longa, and Glycyrrhiza glabra.

Honeybee and Plant Products as Natural Antimicrobials in Enhancement of Poultry Health and Production

The quality and safety attributes of poultry products have attracted increasing widespread attention and interest from scholarly groups and the general population. As natural and safe alternatives to synthetic and artificial chemical drugs (e.g., antibiotics), botanical products are recently being used in poultry farms more than 60% of the time for producing organic products. Medicinal plants, and honeybee products, are natural substances, and they were added to poultry diets in a small amount (between 1% and 3%) as a source of nutrition and to provide health benefits for poultry. In addition, they have several biological functions in the poultry body and may help to enhance their welfare. These supplements can increase the bodyweight of broilers and the egg production of laying hens by approximately 7% and 10% and enhance meat and egg quality by more than 25%. Moreover, they can improve rooster semen quality by an average of 20%. Previous research on the main biological activities performed by biotics has shown that most research only concentrated on the notion of using botanical products as growth promoters, anti-inflammatory, and antibacterial agents. In the current review, the critical effects and functions of bee products and botanicals are explored as natural and safe alternative feed additives in poultry production, such as antioxidants, sexual-stimulants, immuno-stimulants, and for producing healthy products.

The Use of Lavender (Lavandula angustifolia) Essential Oil as an Additive to Drinking Water for Broiler Chickens and Its In Vitro Reaction with Enrofloxacin

Biological activity of lavender essential oil is a property that can potentially find an application in poultry nutrition. Nowadays, the use of bioactive compounds is encouraged in many areas of industry and agriculture, since these substances have similar properties as withdrawn antibiotic growth promoters. Additionally, antibiotic resistance bacteria are one of the most important current threats to animal health. The purpose of the study was to determine the influence of lavender essential oil on the production parameters and blood parameters in broiler chickens and to assess the lavender oil's in vitro reaction in a combination with enrofloxacin towards Escherichia coli. One-day-old non-sexed chicks (Ross 308) were divided into three experimental groups, each consisting of 100 individuals (five replicate of 20 boiler chicken each). The chickens in the control group received drinking water with no addition of lavender essential oil. In the experimental groups, lavender oil was added to the drinking water at a concentration of 0.4 mL/L, in the LEO_1-42 from 1 to 42 days of age and the LEO_22-42 group from the 22 to 42 days of age. The chickens' body weight, feed consumption, water consumption, deaths and elimination due to health reasons were determined in the experiment. On day 42 of the chickens' lives, blood samples were collected based on which selected parameters were identified. An in vitro experiment of lavender oil in combination with enrofloxacin was investigated with a checkerboard method. The results of the experiment showed the antimicrobial and antioxidant activity of lavender essential oil and its positive effect on the production results of broiler chickens. The study results proved that the addition of lavender oil positively impacted the chickens' final body weight and feed conversion ratio (p < 0.01). No differences were observed between the groups for water consumption, death rate and the examined biochemical and immunological blood serum indices. Lavender essential oil was demonstrated to increase the blood serum's total antioxidant status. A synergistic reaction in vitro was observed for lavender oil combined with enrofloxacin against resistant strains of Escherichia coli. Based on our study, a health-promoting effect of adding LEO to water for broiler chickens was found. Moreover, in vitro studies indicate a significant effect of lavender essential oil on the inhibition of the resistant strains of Escherichia coli growth and synergistic reaction with enrofloxacin.

Approaches to prevent and control Campylobacter spp. colonization in broiler chickens: a review

Campylobacter, Gram-negative bacteria, is the most common cause of acute bacterial enteritis in human beings, both in developing and developed countries. It is believed that poultry, in particular broiler chickens, is the main host of human infection with Campylobacter. Handling and consumption of contaminated chicken meat are the usual modes of transmission. Prevention and reduction of Campylobacter colonization in poultry farms will cut off the road of infection transmission to humans throughout the food chain. With the incidence of antibiotic resistance and with growing concern about superbugs, the search for natural and safe alternatives will considerably increase in the coming years. In this review, we will discuss the prevalence and risk factors of Campylobacter colonization in broiler chickens and sources of infection. This review also provides extensive and recent approaches to prevent and control Campylobacter colonization in broiler chickens, including biosecurity measures, natural feed/drinking water additives with antimicrobial properties, bacteriocins, bacteriophages, antimicrobial peptides, and vaccination strategies to prevent and control the incidence of human campylobacteriosis.

Romero (Rosmarinus officinalis L.): su origen, importancia y generalidades de sus metabolitos secundarios

El presente trabajo, es una revisión que muestra el impacto que tiene el uso de las plantas medicinales en la salud humana. Desde la antigüedad, por tradición, se extendió el uso mayoritario de algunas familias vegetales como la Lamiaceae que destaca por sus propiedades aromáticas y aplicación culinaria en numerosas culturas, así como en el tratamiento y prevención de una gran variedad de enfermedades y malestares. Dentro de las especies pertenecientes a esta familia se encuentra el romero (Rosmarinus officinalis), planta que ha ganado importancia en el campo de la investigación por sus diversos atributos biológicos como: antiinflamatorio, antimicrobiano, antioxidante y anticancerígeno, entre otros; resultados que debe a sus metabolitos secundarios como: el ácido carnósico, el carnosol, el ácido rosmárico y  el alcanfor, entre otros más, aunado a un potencial efecto cuando es aplicado. También se mencionan algunas metodologías que buscan la extracción de los componentes biológicamente activos del romero.

Sustainability and Quality Aspects of Different Table Egg Production Systems: A Literature Review

Eggs are of considerable importance in feeding the population, as they are a relatively inexpensive and complex food source of very high biological value. The daily animal protein requirement for the human body can be covered with eggs in the cheapest way and with the lowest environmental impact. As animal welfare, as well as environmental and health awareness issues, become increasingly prominent in developed countries, consumer demand for eggs has also changed significantly in recent years, with an increasing number of consumers buying eggs produced in non-cage housing systems. In recent years, cage housing has been more frequently debated in EU member states. An initiative was launched in 2018 to end cage housing technologies and the sale of eggs produced in this way. However, in addition to animal welfare, a number of other factors need to be considered in relation to sustainable production. For this reason, the aim of this research is to provide a comprehensive overview of the sustainability issues of various housing technologies, as well as quality factors affecting consumer health and egg consumption based on the relevant international references and databases. Although there is a growing demand for products produced in non-cage housing systems due to the increasing relevance of environmental protection, health awareness and animal welfare issues in Western societies, research has shown that non-caged production is not the best solution for environmentally, socially and economically sustainable egg production.

Impact of Housing Environment on the Immune System in Chickens: A Review

During their lifespan, chickens are confronted with a wide range of acute and chronic stressors in their housing environment that may threaten their welfare and health by modulating the immune system. Especially chronic stressful conditions can exceed the individual's allostatic load, with negative consequences for immunity. A fully functional immune system is mandatory for health and welfare and, consequently, also for high productivity and safe animal products. This review provides a comprehensive overview of the impact of housing form, light regime as well as aerial ammonia and hydrogen sulfide concentrations on the immune system in chickens. Certain housing conditions are clearly associated with immunological alterations which potentially impair the success of vaccinations or affect disease susceptibility. Such poor conditions counteract sustainable poultry production. This review also outlines current knowledge gaps and provides recommendations for future research.

Consequences of various housing systems and dietary supplementation of thymol, carvacrol, and euganol on performance, egg quality, blood chemistry, and antioxidant parameters

The present work was carried out to investigate the influences of housing system and dietary essential oils (EOs) supplementation to laying hens on the productive performance, egg quality, immunity, antioxidant parameters, and hematology. A factorial arrangement (2 × 4) was performed, including 2 housing systems and 4 different types of EOs (without EOs, thymol, carvacrol, and euganol) during the production stages (from 28–78 wk of age). Birds were randomly divided into 2 groups with each of 2,000 birds. The first group was moved to laying cages while the second group was a floor reared. Each group was randomly divided into 4 groups (5 replicates of 100 birds each): The first were considered as a control group, and the second, third, and fourth groups were treated with thymol, carvacrol, and euganol EO, respectively. The results showed that hens reared in cage system had higher egg weight (P < 0.05), egg production, egg mass, and feed intake and better feed conversion ratio (P < 0.001) than those reared in the floor system. Blood picture values (except white blood cells), phagocytic index, phagocytic activity, and blood chemistry parameters (except calcium, phosphorus, and urea values) of laying hens were not affected (P > 0.05) by housing system. The groups fed EOs showed a rapid improvement (P < 0.001) in the egg production%, egg weight, egg mass, and egg quality. Thymol group had the highest egg production (P < 0.001). Thymol and eugenol groups had the highest egg weight, egg mass, and egg quality (P < 0.001). The groups fed diets containing thymol or eugenol consumed lower feed and had better feed conversion ratio (P < 0.001) than the control group. Immunity indices (phagocytic activity [P < 0.05], avian influenza [AIH5 and AIH9], P < 0.001) were improved with the presence of EOs in the laying hen diet. These results strongly suggest that dietary EO supplementation could be a successful attempt to improve the productive performance, egg quality, and immunity of laying hens.

Cinnamon (Cinnamomum zeylanicum) Oil as a Potential Alternative to Antibiotics in Poultry

The removal of antibiotic growth promoters (AGPs) as feed additives in poultry nutrition from the market in many countries has compelled researchers to find unconventional and safe alternatives to AGPs. Probiotics, prebiotics, enzymes, organic acids, herbs, immune-stimulants and essential oils (EO) have been investigated as feed additives in poultry production. Cinnamon (Cinnamomum zeylanicum), one of the oldest medicinal plants and widely used around the world, can be used in poultry rations in the form of powder or essential oil. Essential oils produced from aromatic plants have become more interesting owing to their potential effects as hypocholesterolaemic agents, antioxidants, antimicrobials, antifungals and stimulants of digestive enzymes. The potential insecticidal and antimicrobial activities of EO against pathogens that cause spoilage in agriculture crops and human diseases might be attributed mainly to the high content of volatile components (mainly cinnamaldehyde, eugenol and carvacrol) in cinnamon oil. The present review focuses on the effects of cinnamon oil as a feed additive on poultry performance, carcass traits, meat quality, hypocholesterolaemic impact, antioxidant activity, immunity and microbiological aspects.