Effects of supplementing hen diet with Lavandula angustifolia and/or Mentha spicata essential oils on production performance, egg quality and blood variables of laying hens

Newcastle viral disease causation web correlations with laying hen productivity

Environmental conditions profoundly impact the health, welfare, and productivity of laying hens in commercial poultry farming. We investigated the association between microclimate variations, production indices, and histopathological responses to accidental Newcastle disease virus (NDV) infection within a controlled closed-house system. The study was conducted over seven months in a laying hen facility in Cairo, Egypt. Microclimate measurements included temperature, relative humidity (RH%), air velocity (AV), and the temperature humidity index (THI) that were obtained from specific locations on the front and back sides of the facility. Productivity indices, including the egg production percentage (EPP), egg weight (EW), average daily feed intake, and feed conversion ratio, were assessed monthly. During an NDV outbreak, humoral immune responses, gross pathology, and histopathological changes were evaluated. The results demonstrated significant (p < 0.05) variations in EPP and EW between the front and back sides except in April and May. AV had a significant (p = 0.006) positive effect (Beta = 0.346) on EW on the front side. On the back side, AV had a significant (p = 0.001) positive effect (Beta = 0.474) on EW, while it negatively influenced (p = 0.027) EPP (Beta = - 0.281). However, temperature, RH%, and THI had no impact and could not serve as predictors for EPP or EW on either farm side. The humoral immune response to NDV was consistent across microclimates, highlighting the resilience of hens. Histopathological examination revealed characteristic NDV-associated lesions, with no significant differences between the microclimates. This study underscores the significance of optimizing microclimate conditions to enhance laying performance by providing tailored environmental management strategies based on seasonal variations, ensuring consistent airflow, particularly near cooling pads and exhaust fans, and reinforcing the importance of biosecurity measures under field challenges with continuous monitoring and adjustment.

Phytogenic feed additives as natural antibiotic alternatives in animal health and production: A review of the literature of the last decade

The use of antibiotics in animal production raises great public safety concerns; therefore, there is an urgent need for the development of substitutes for antibiotics. In recent decades, plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development. This review summarizes the research history and classification of phytogenic feed additives and their main functions, potential modes of action, influencing factors, and potential negative effects. Further, we highlight the challenges in developing sustainable, safe, and affordable plant-derived antibiotic alternatives for use in livestock production.

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.

Plant essential oils improve growth performance by increasing antioxidative capacity, enhancing intestinal barrier function, and modulating gut microbiota in Muscovy ducks

Essential oils (EO) are known for their antioxidant, anti-inflammatory, antimicrobial, and growth-promoting properties. However, data rgarding their impact on the intestinal health and gut microbiota of ducks remain limited. Thus, this study aimed to investigate the effects of plant EO on the growth performance, intestinal health, and gut microbiota of Muscovy ducks. A total of 360 healthy male Muscovy ducks aged 1 d were randomly divided into 4 groups with 6 replicates and 15 ducks per replicate. Ducks were fed basal diets supplemented with 0, 100, 200, or 300 mg/kg EO. The results showed that 200 mg/kg EO supplementation significantly (P < 0.05) increased the final body weight and average daily gain, while significantly (P < 0.05) decreased the feed conversion ratio during the 56-d experimental period. Furthermore, dietary 200 mg/kg EO significantly (P < 0.05) enhanced antioxidant capacity and immune function and improved the barrier function of the intestine. Additionally, 16S rDNA sequencing analysis results showed that 200 mg/kg EO favorably modulated the cecal microbial diversities and composition evidenced by the increased (P < 0.05) the abundances of short-chain fatty acid-producing bacteria (e.g., Subdoligranulum and Shuttleworthia) and decreased (P < 0.05) abundances of potential enteric pathogenic bacteria (e.g., Alistipes, Eisenbergiella, and Olsenella). The relative abundance of beneficial bacteria was positively correlated with antioxidant, immune, and barrier function biomarkers. Overall, these findings revealed that dietary supplementation with 200 mg/kg EO had several potentially beneficial effects on the growth performance of Muscovy ducks by improving antioxidant capacity, enhancing the intestinal barrier function and favorably modulating gut microbiota.

Effects of Essential Oils and Fragrant Compounds on Appetite: A Systematic Review

Appetite dysregulation is one of the factors contributing to anorexia, bulimia nervosa, obesity, and diabetes. Essential oils or fragrant compounds have been proven to regulate food intake and energy expenditure; hence, this study aimed to summarize their effects on appetite and the underlying mechanisms. The PubMed and Web of Science databases were searched until July 2022. Only two of the 41 studies were performed clinically, and the remaining 39 used animal models. Oral administration was the most common route, and a dosage range of 100-2000 mg/kg for mice or 2-32 mg/kg for rats was applied, with a duration of 12 days to 4 weeks, followed by inhalation (10^-6-10^-3 mg/cage or 10^-9-10^-2 mg/cm³ within 1 h). Approximately 11 essential oil samples and 22 fragrant compounds were found to increase appetite, while 12 essential oils and seven compounds decreased appetite. These fragrant components can exert appetite-regulating effects via leptin resistance, the activity of sympathetic/parasympathetic nerves, or the mRNA expression of neuropeptide Y (NPY)/agouti-related protein (AgRP), cocaine- and amphetamine-regulated transcript (CART)/proopiomelanocortin (POMC) in the hypothalamus. Fragrance memory and cognitive processes may also play roles in appetite regulation. The findings of this study accentuate the potential of essential oils and fragrant compounds to regulate appetite and eating disorders.

Effect of adding lavender oil to laying quail diets on performance, egg quality, oxidative status, and fatty acid profile

This study aims to investigate the effects of lavender essential oil on performance, egg quality parameters in quails, malondialdehyde (MDA) in fresh and stored (28 days at ₊4°C) eggs, and individual and total fatty acids. To this end, 100 female quails (Coturnix coturnix Japonica) which were 5 weeks old with an average weight of 224 g were used. The study lasted 45 days, including 10 days of introduction and 35 days of study. Quails were fed ad libitum with four different treatments. Four groups were formed as control groups (0g lavender essential oil/kg feed), Lav125 (125mg lavender essential oil/kg feed), Lav250 (250mg lavender essential oil/kg feed), and Lav500 (500mg lavender essential oil/kg feed). There were five subgroups under each group and five quails in each subgroup. Feed consumption and egg weight parameters increased in Lav500 group compared to the control group (p<0.05). The highest egg yield compared to the control group was determined in Lav500 group (p>0.05), and the highest egg mass compared to the control group was determined in Lav125 group. The highest feed conversion ratio compared to the control group was in Lav250 group (p>0.05). In addition, egg white height and Haugh Unit (HU) compared to the control group were the highest in Lav500 group (p<0.05). The MDA concentration decreased in Lav125 and Lav250 group in fresh and in Lav500 group in stored eggs (at +4C for 28 days) compared to the control group (p<0.05). Omega 3 fatty acids in fresh and stored eggs were higher in lavender groups compared to the control group (p<0.05). However, the concentration of omega 9 (oleic acid) fatty acid decreased in the lavender groups compared to the control group (p<0.05). As a result, it was found that adding lavender essential oil to the diet leads to an increase in body weight, egg yield, egg mass, egg weight, egg white height, HU, omega 3 fatty acids, and a decrease in MDA concentration.

A Novel Phytogenic Formulation, EUBIO-BPSG, as a Promising One Health Approach to Replace Antibiotics and Promote Reproduction Performance in Laying Hens

Gut microbiota play a key role in health maintenance and disease pathogenesis in animals. Dietary phytochemicals are crucial factors shaping gut bacteria. Here, we investigated the function and mechanism of a phytogenic formulation, EUBIO-BPSG (BP), in laying hens. We found that BP dose-dependently improved health and egg production in 54-week-old hens. Furthermore, BP was correlated with increased fecal Lactobacillus, decreased Escherichia coli and Salmonella enterica, and reduced antibiotic resistance (AR) and antibiotic resistance genes (ARG) in chicken stools. The 16S rDNA data showed that BP increased seven genera of probiotics and reduced 13 genera of pathogens in chicken feces. In vitro co-culture experiments showed that BP at 4 µg/mL and above promoted growth of L. reuteri while large 100- and 200-fold higher doses suppressed growth of E. coli and S. enterica, respectively. Mechanistic studies indicated that L. reuteri and its supernatants antagonized growth of E. coli and S. enterica but not vice-versa. Five short-chain fatty acids and derivatives (SCFA) produced from L. reuteri directly killed both pathogens via membrane destruction. Furthermore, BP inhibited conjugation and recombination of ARG via interference with conjugation machinery and integrase activity in E. coli. Collectively, this work suggests that BP promotes host health and reproductive performance in laying hens through regulation of gut microbiota through increasing probiotics and decreasing pathogens and spreading ARG.

Antioxidant properties and cytotoxic effects of selected edible plants in Southeast Asia for further use as phytogenic antioxidant additives

Excessive free radicals in human and animal bodies can cause oxidative stress (OS) which damages cells and tissues. Plant materials with high antioxidant potential would resolve the OS problem. Thus, this study proposed to investigate the total phenolic (TPC) and flavonoid contents (TFC), antioxidant capacities and cytotoxicity in 17 edible plant materials from herbs, fruits, vegetables and plant by-products available in Southeast Asia for future use in the food or feed industry. Among 17 plant materials, Syzygium aromaticum (clove), Camellia sinensi (green tea pomace) from the beverage industry and Persicaria odorata (Vietnamese coriander) showed a prominent amount of TPC and TFC. These three plants and their combination (1:1:1 ratio, v:v:v) also possessed a remarkable antioxidant function in terms of DPPH, ABTS and FRAP, as well as showing a strong ROS inhibition through HepG2 cells. The cytotoxicity test of the crude extract of clove, green tea pomace and Vietnamese coriander, or their combination can be used between 0.032 and 0.255, 0.011 to 0.088, 0.022 to 0.178 and 0.021 to 0.346 mg/mL, respectively, without impeding cell viability. A combined mixture of clove, green tea pomace and Vietnamese coriander revealed the synergistic properties of antioxidants and cell safety. This indicates that there is a potential use of various antioxidant bioactive compounds in plant materials tested for use as phytogenic antioxidant additives.

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.

Natural Products of Plants and Animal Origin Improve Albumen Quality of Chicken Eggs

Albumen quality is recognized as one of the major yardsticks in measuring egg quality. The elasticity of thick albumen, a strong bond in the ovomucin-lysozyme complex, and excellent biological properties are indicators of high-quality albumen. The albumen quality prior to egg storage contribute to enhance egg’s shelf life and economic value. Evidence suggests that albumen quality can deteriorate due to changes in albumen structure, such as the degradation of β-ovomucin subunit and O-glyosidic bonds, the collapse of the ovomucin-lysozyme complex, and a decrease in albumen protein-protein interaction. Using organic minerals, natural plants and animal products with antioxidant and antimicrobial properties, high biological value, no residue effect and toxicity risk could improve albumen quality. These natural products (e.g., tea polyphenols, marigold extract, magnolol, essential oils, Upro (small peptide), yeast cell wall, Bacillus species, a purified amino acid from animal blood, and pumpkin seed meal) are bio-fortified into eggs, thus enhancing the biological and technological function of the albumen. Multiple strategies to meeting laying hens’ metabolic requirements and improvement in albumen quality are described in this review, including the use of amino acids, vitamins, minerals, essential oils, prebiotics, probiotics, organic trace elements, and phytogenic as feed additives. From this analysis, natural products can improve animal health and consequently albumen quality. Future research should focus on effects of these natural products in extending shelf life of the albumen during storage and at different storage conditions. Research in that direction may provide insight into albumen quality and its biological value in fresh and stored eggs.

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.

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.

Influence of Lavandula angustifolia, Melissa officinalis and Vitex angus-castus on the organism of rats fed with excessive fat-containing diet

Plant food additives are becoming more and more popular and broadly applied products, though the information on risks they poses to the organism is limited and contradictive. Obesity and overeating are some of the commonest health issues around the world, and people are increasingly consuming workability-enhancing preparations as a simple and fast method of weight control. The plant-based preparations are considered less harmful than the synthetic chemical ones. Lavandula angustifolia Mill., Melissa officinalis L. and Vitex angus-castus L. are broadly used as food additives and medicinal plants, despite the fact that their complex physiological assessment on model animals in the conditions of obesity has not yet been performed. We carried out a 30-day experiment on white male rats. All the animals were given high-fat diet, and the experimental animals, in addition to this diet, received 5% crumbled dry herbs of L. angustifolia, M. officinalis or V. angus-castus. Taking into account the overall amount of consumed food, the mean daily gain in body weight; at the end of the experiment, we determined the index of the weight of the internal organs, biochemical and morphological blood parameters. At the beginning and the end of the experiment, the rats were examined for motor and orienting activities, and emotional status. Rats on high-fat diet gained up to 112% body weight by the end of the experiment, while rats that had received V. angus-castus gained up to 119%, M. officinalis – 135%, L. angustifolia – 139%, compared with the initial body weight. Addition of medicinal plants to the diet led to increase in average daily weight increment, significantly and reliably after consuming lavender and lemon balm, less significantly and unreliably after eating Vitex. L. angustifolia and M. officinalis reduced the relative brain weight, and ingestion of L. angustifolia and M. officinalis caused notable decrease in the relative mass of the thymus (down to 58% and 47% of the relative weight of thymus in animals of the control group respectively). Also, these plants decreased the motor and orienting activities of the rats by the end of the experiment. As for the biochemical parameters of blood, the activity of alkaline phosphatase significantly increased to 406% following consumption of Melissa, to 350% after consuming lavender, and to 406% after Vitex, compared to the control group. Furthermore, all the groups were observed to have increased AST and ALT activities. Intake of lavender led to increases in cholesterol (to 125%) and LDL cholesterol (to 228%), whereas the groups that consumed lemon balm were observed to have decreases in urea nitrogen (to 79%), totalbilirubin (to 63%) and triglycerides (to 63%). Addition of Vitex led to increase in the index of aterogenecity against the background of notable fall in HDL cholesterol (to 52% of the control group). The medicinal plants also contributed to the normalization of the glucose level. Morphological analysis of blood revealed no significant changes, except heightened content of monocytes in blood, which is characteristic of all groups, including the control. Effects of L. angustifolia, M. officinalis and V. angus-castus on the organism of rats on excessive-fat diet require additional histological, histochemical and immunological surveys.

Effects of supplementing hen diet with Lavandula angustifolia and/or Mentha spicata essential oils on production performance, egg quality and blood variables of laying hens

Background

Organic products of animals are getting more accepted by consumers. Using herbal additives may lead to more health animal products. In this research it is hypothesized that Lavandula angustifolia and/or Mentha spicata essential oils would be helpful to enhance production performance in laying hens.

Objectives

This experiment was conducted to evaluate the effects of Lavandula angustifolia and Mentha spicata essential oils on performance, egg traits and blood variables in laying hens.

Methods

144 Lohmann LSL‐Lite laying hens from 42 until 56 weeks of age were used in a completely randomized design in four treatments and six replicates (six birds per replicate). The treatments consisted of: (a) control group (basal diet), (b) basal diet supplemented with 250 mg/kg diet lavender essential oil (LEO), (c) basal diet supplemented with 250 mg/kg diet mint essential oil (MEO), and (d) basal diet supplemented with both LEO and MEO.

Results

Using LEO and/or MEO did not affect body weight changes, feed intake, egg weight, egg index, yolk index, Haugh unit, egg shell weight and egg shell thickness. Feeding LEO, individually or in combination with MEO, did not affect FCR compared with the control group (p < .05), however, feeding MEO individually increased feed conversation ratio (FCR) compared to LEO and the control group during 42–56 weeks (p < .05), as well as decreasing egg mass compared to LEO (p < .05). Feeding LEO increased egg production compared to MEO and combination of MEO and LEO (p < .05).

Conclusions

In conclusion, dietary supplemental MEO (250 mg/kg) may increase FCR, and LEO (250 mg/kg) is more effective than MEO (250 mg/kg) for egg production and egg mass purposes; besides MEO (250 mg/kg) negatively affected FCR compared with the control group. In addition, no specific beneficial effect of dietary supplemental MEO and/or LEO on the other measured variables was detected.