Effect of dietary supplementation of thymol, synbiotic and their combination on performance, egg quality and serum metabolic profile of Hy-Line Brown hens

Optimizing the scale-up production of fermented astragalus and its benefits to the performance and egg quality of laying hens

Astragalus is a homologous medicine and food that benefits human beings and poultry rearing. Fermented astragalus (FA) is a valuable product obtained by fermentation, but its scale-up production requires optimization and expansion of solid-state fermentation (SSF). In this study, Lactobacillus pentosus Stm was screened as the most suitable LAB strain for fermenting astragalus due to its excellent capacity. After optimization and expansion of SSF, LAB count and lactic acid content reached 206 × 108 cfu/g and 15.0%, respectively. Meanwhile, the content of bioactive compounds in FA was significantly enhanced. Feeding experiments with laying hens indicated that supplementing FA in the diet significantly improved the performance and egg quality, as evidenced by reduced feed-to-egg ratio and egg cholesterol. This was due to the promotion of intestinal health by shifting intestinal microbiota. Therefore, this is a systematical endeavor of producing scaled-up FA with promising potential as a feed additive in the poultry breeding industry.

Dietary Oregano Essential Oil Supplementation Influences Production Performance and Gut Microbiota in Late-Phase Laying Hens Fed Wheat-Based Diets

This study aimed to investigate the potential effects of OEO on production performance, egg quality, fatty acid composition in yolk, and cecum microbiota of hens in the late phase of production. A total of 350 58-week-old Jing Tint Six laying hens were randomly divided into five groups: (1) fed a basal diet (control); (2) fed a basal diet + 5 mg/kg flavomycin (AGP); (3) fed a basal diet + 100 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO1); (4) fed a basal diet + 200 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO2); (5) fed a basal diet + 300 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO3). Compared to the control group, group EO2 exhibited higher (p < 0.05) egg production during weeks 5−8 and 1−8. EO2 had a lower feed conversion ratio than the control group during weeks 1−8. The content of monounsaturated fatty acid (MUFA) in EO2 was higher (p < 0.05) than that of the control and AGP groups. EO2 increased (p < 0.05) the abundance of Actinobacteriota and decreased the abundance of Desulfovibri in the cecum. The abundances of Anaerofilum, Fournierella, Fusobacterium, and Sutterella were positively correlated with egg production, feed conversion ratio, and average daily feed intake, while the abundances of Bacteroides, Desulfovibrio, Lactobacillus, Methanobrevibacter, and Rikenellaceae_RC9_gut_group were negatively correlated with egg production, feed conversion ratio, and average daily feed intake. Dietary supplementation with 200 mg/kg OEO and 20 mg/kg cinnamaldehyde could improve egg-production performance, decrease feed conversion ratio, and alter the fatty acid and microbial composition of eggs from late-phase laying hens.

Effects of Dietary Essential Oils Supplementation on Egg Quality, Biochemical Parameters, and Gut Microbiota of Late-Laying Hens

The objective of this study was to explore the effects of adding essential oils (EO) to diets on egg quality, biochemical parameters and intestinal flora of late laying hens. The number of 252 Dawu Golden Phoenix laying hens (55 weeks old) were randomly sorted into two groups: the control group (CG) fed a basal diet and the EO group fed a basal diet with 300 mg/kg of essential oils. The average egg weight, feed-to-egg ratio, and egg production rate were determined every week. The trial started at week 55 and lasted for 8 weeks. During the experiment’s last week, 36 eggs out of each group were chosen at random to test. In our study, dietary supplementation with EO considerably decreased the egg breaking rate (p = 0.01) and increased the shell-breaking strength (p = 0.04). The treatment group’s alanine aminotransferase (ALT) levels were considerably lower than those of the control group (p = 0.03). The EO group had substantially higher total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) (p = 0.04 and p =0.03, respectively). However, there were no differences in alpha diversity indicators between the two groups. It is worth noting that Firmicutes were increased considerably (p < 0.05), while Spirochaetota and Proteobacteria were significantly reduced in the EO group. At genus levels, the EO supplementation increased the relative abundance of Intestinimonas (p < 0.05) and Megamonas (p < 0.01). In conclusion, a dietary supplementation of 300 mg/kg EO can improve the production performance of laying hens and the egg quality. It can also regulate the abundance of cecal flora and serum biochemical indicators.

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.

Effect of 25-hydroxyvitamin D and essential oil complex on productive performance, egg quality, and uterus antioxidant capacity of laying hens

This study was conducted to determine the effect of 25-hydroxyvitamin D (HDV) and essential oils (EO) on the uterus antioxidant capacity, egg quality, and eggshell ultrastructure in laying hens. A total of 400 48-wk-old Lohmann laying hens were randomly allocated into 2 groups and fed a basal diet (control) or a basal diet supplemented with a combination of 69 μg/kg HDV and EO (including 200 mg/kg thymol and 50 mg/kg carvacrol) for 12 wk. There are 10 replicates of 20 hens each. Compared with the control, dietary HDV+EO supplementation improved (P < 0.05) egg production rate, feed efficiency, eggshell thickness and strength, and decreased (P < 0.05) the translucent egg score. Ultrastructural changes indicated that dietary HDV+EO supplementation decreased (P < 0.05) mammillary knob width, mammillary thickness and the proportion of mammillary thickness, and increased (P < 0.05) the proportion of effective thickness and total thickness of the eggshells compared with the control. Supplementation with HDV+EO complex led to higher serum HDV concentration and increased antioxidant capacity in the uterus, indicated by higher (P < 0.05) antioxidant enzyme activities (catalase [CAT], total antioxidant capacity [T-AOC], and glutathione S-transferases [GST]) and lower malondialdehyde (MDA) content. Therefore, dietary HDV and EO complex (including thymol and carvacrol) supplementation can improve the productive performance and the eggshell quality in laying hens, and the improving effect on eggshell quality may through enhancing eggshell ultrastructure and antioxidant capacity of uterus.

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.

Moringa oleifera Leaves as Eco-Friendly Feed Additive in Diets of Hy-Line Brown Hens during the Late Laying Period

Simple Summary

It is of the utmost importance to explore the merit of a new phytogenic feed additive for sustainable egg production in laying chickens during the late laying period. Thus, the current study was designed to evaluate the effect of the addition of Moringa oleifera leaves to laying hen diets on laying performance, egg quality, excreta ammonia concentrations and blood biochemical parameters. The findings showed that the egg production, weight and mass and eggshell quality of laying hens fed with Moringa oleifera leaves during the late laying period were significantly improved in comparison with those of the hens in the control group. Moringa oleifera leaves supplementation decreased excreta ammonia concentration and serum cholesterol and triglycerides as well as serum liver enzymes, uric acid, and creatinine levels compared to those of the control group.

Abstract

This study investigated the dietary effects of Moringa oleifera leaves supplementation on egg quality, laying performance, excreta ammonia concentrations and serum biochemistry of laying chickens during the late laying period. A total of 240 64-week-old Hy-Line Brown hens were assigned to four treatment diets including Moringa oleifera leaves at 0, 3, 6 or 9 g/kg, respectively, for eight weeks. The treatments had twelve replicates with five hens each. The results revealed that incremental dietary Moringa oleifera leaves significantly increased (p < 0.01) egg weight, production, and mass through 64–68, 68–72 and 64–72 weeks of age. Simultaneously, feed conversion ratio was significantly improved (p < 0.01) with Moringa oleifera leaves supplementation compared with the control. Haugh units and the thickness of eggshells significantly improved as a response to diets supplemented with 3, 6 and 9 g/kg Moringa oleifera leaves at 72 weeks of age. Interestingly, excreta ammonia concentrations, serum cholesterol, aspartate transaminase and alanine aminotransferase significantly decreased by Moringa oleifera leaves supplementation compared with the control group. In conclusion, introducing Moringa oleifera leaves supplementation at 3, 6 and 9 g/kg increased egg production, eggshell quality, Haugh units, and decreased serum cholesterol, triglycerides, excreta ammonia concentrations besides serum liver enzymes, uric acid and creatinine. Overall, based on the observed results, Moringa oleifera leaves supplementation was very promising and these leaves could be used as an effective feed additive in laying hens’ diet during the late laying period.

Cholesterol-lowering activity of natural mono- and sesquiterpenoid compounds in essential oils: A review and investigation of mechanisms using in silico protein-ligand docking

Mono- and sesquiterpenoids are the main chemical constituents of essential oils. Essential oils and their constituents have received increasing attention for lipid-lowering properties in both cell and animal models. Despite the chemical diversity of essential oil compounds, the effects of many of these compounds on cholesterol metabolism are highly similar. In this report, we review the literature regarding the effects of essential oils and their terpenoid constituents on cholesterol homeostasis, and explore likely mechanisms using protein-ligand docking. We identified 98 experimental and seven clinical studies on essential oils, isolated compounds, and blends; 100 of these described improvements either in blood cholesterol levels or in sterol metabolic pathways. Our review and docking analysis confirmed two likely mechanisms common to many essential oil compounds: (1) direct agonism of peroxisome-proliferator-activated receptors, and (2) direct interaction with sterol-sensing domains, motifs found in key sterol regulatory proteins including sterol regulatory element binding protein cleavage activating protein and HMG-CoA reductase. Notably, these direct interactions lead to decreased transcription and accelerated degradation of HMG-CoA reductase. Our work suggests that terpene derivatives in essential oils have cholesterol-lowering activity and could potentially work synergistically with statins, however, further high quality studies are needed to establish their clinical efficacy.

Effects of oregano (Lippia origanoides) essential oil supplementation on the performance, egg quality, and intestinal morphometry of Isa Brown laying hens

Background and Aim:

The use of antibiotics as growth promoters in the feed of poultry, has contributed to an increase in the antimicrobial resistance of foodborne pathogens worldwide. Hence, the development of new effective alternatives to antibiotics that do not hinder productivity is imperative. For this, the aim of the present study was to determine whether oregano essential oil (OEO) extracted from Lippia origanoides is a suitable alternative to growth-promoting antibiotics (GPAs) for improving the performance, egg quality, and intestinal morphometry of ISA Brown laying hens.

Materials and Methods:

A total of ninety-six 70-week-old ISA Brown laying hens were randomly assigned to four treatment groups with four replicates per treatment and six hens per replicate. The treatments consisted of four different diets that were formulated according to the nutritional requirements of the genetic line and the production phase with and without the addition of GPA and OEO: NC, which did not contain OEO or GPA; GPA, which included 50 ppm zinc bacitracin as a GPA; 80OEO, which included 80 ppm OEO and no GPA; and 150OEO, which included 150 ppm OEO and no GPA.

Results:

All of the OEO and GPA treatment groups had a better feed conversion ratio than the NC group. However, the addition of 150 ppm OEO to the diet improved the percentage egg production and egg mass, as well as the external and internal quality of the egg compared with the other treatments. In addition, both the 80OEO and 150OEO treatments improved the yolk color, shell thickness, and shell color, as well as parameters related to the intestinal morphometry compared with the NC group.

Conclusion:

The findings of this study indicate that 150 ppm OEO can be used as a substitute for GPA to improve the performance, egg quality, and parameters related to the intestinal morphometry of ISA Brown laying hens.

Short- and long-term dynamics of the physiological and behavioral response to heat stress and thymol supplementation in Japanese quail

Organisms have evolved endogenous timing systems that enable them to predict temporal changes and to coordinate complex internal processes. However, temporal dynamics of biological responses are most often ignored in fields such as dietary supplementation of farm animals exposed to artificial environmental challenges. Herein, we hypothesized that the potential for thymol (2-isopropyl-5-methylphenol) to alleviate physiological and behavioral consequences of heat stress is time-dependent on both long-term (i.e. weeks) and short-term (i.e. within day) time scales. First, during 3-weeks adult female Japanese quail (Coturnix japonica) were exposed daily to 9h of increased environmental temperature (34.2 ± 0.1 °C). Controls remained at standard temperatures (23.6 ± 0.1 °C). Simultaneously, half received thymol dietary supplementation and the other half a control basal diet. On day 4, both thymol and heat stress decreased body weight and feed intake respect to controls (basal, standard temperature). After three weeks, feed intake recovered for thymol groups. Therefore, we performed a second experiment focused on the critical first week of treatment, sampling variables three times a day. The beneficial effects of thymol supplementation were mainly observed during the morning, including prevention of high respiratory rates and reduction in the weight of droppings induced by heat stress, and increased walking under both temperatures. In summary, thymol's potential for alleviating heat stress consequences is time-dependent, and can be conceived as an emergent property resulting from the complex interplay between the dynamics of the biological response to thymol and heat stress. Findings highlight the importance of considering time-related factors when developing supplementation protocols to mitigate environmental challenges.

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.

The Gut Microbiota of Laying Hens and Its Manipulation with Prebiotics and Probiotics To Enhance Gut Health and Food Safety

The microbiota plays a vital role in maintaining gut health and influences the overall performance of chickens. Most gut microbiota-related studies have been performed in broilers, which have different microbial communities compared to those of layers. The normal gut microbiota of laying chickens is dominated by Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria at the phylum level. The composition of the gut microbiota changes with chicken age, genotype, and production system. The metabolites of gut microbiota, such as short-chain fatty acids, indole, tryptamine, vitamins, and bacteriocins, are involved in host-microbiota cross talk, maintenance of barrier function, and immune homeostasis. Resident gut microbiota members also limit and control the colonization of foodborne pathogens. In-feed supplementations of prebiotics and probiotics strengthen the gut microbiota for improved host performance and colonization resistance to gut pathogens, such as Salmonella and Campylobacter The mechanisms of action of prebiotics and probiotics come through the production of organic acids, activation of the host immune system, and production of antimicrobial agents. Probiotic candidates, including Lactobacillus, Bifidobacterium, Bacillus, Saccharomyces, and Faecalibacterium isolates, have shown promising results toward enhancing food safety and gut health. Additionally, a range of complex carbohydrates, including mannose oligosaccharides, fructo-oligosaccharides, and galacto-oligosaccharides, and inulin are promising candidates for improving gut health. Here, we review the potential roles of prebiotics and probiotics in the reshaping of the gut microbiota of layer chickens to enhance gut health and food safety.

Use of Tea Tree Essential Oil (Melaleuca alternifolia) in Laying Hen’s Nutrition on Performance and Egg Fatty Acid Profile as a Promising Sustainable Organic Agricultural Tool

The level of production in a variety of organic production systems is often lower than in other traditional production systems. In poultry production, there is also a direct negative effect of the small scale regarding sustainable organic poultry production. Regardless of differences between organic and conventional production systems, this experiment aimed to investigate the usage of tea tree Melaleuca alternifolia (Maiden and Betche) Cheel essential oils as a natural alternative to antibiotics in hen nutrition on productive parameters, table egg quality and eggs fatty acid profile as a promising sustainable organic agricultural tool. A total of 360 Lohmann Brown hens, aged 54 weeks, divided into three different treatment diets, were supplemented with 0 (T1), 40 (T2) and 80 mg/kg (T3) of M. alternifolia essential oil, respectively. Experimental treatments were replicated four times within 30 birds each. The experiment lasted for a total of 56 days (55 to 62 weeks of hens age). A 56-day experimental had two timetable periods of 28 days each: period 1 (55 to 58 weeks of hen age) and period 2 (59 to 62 weeks of hen age). For compound feed supplemented with M. alternifolia essential oil, daily egg production and the efficiency of nutrient utilization (FCR) was improved significantly (p < 0.05) until the end of week 58, with a significant (p < 0.05) increase in the thickness of eggshell, as well as egg production (p < 0.05). However, egg mass, feed consumption, FCR and albumen height, Haugh unit, and eggshell strength did not show any significant (p > 0.05) differences influenced by essential oil feed supplementation. Lower concentrations of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA), and higher concentrations of polyunsaturated fatty acid (PUFA), were recorded with M. alternifolia essential oil supplementation, but without significant (p > 0.05) differences. At the end of the experiment, the obtained results showed that the addition of M. alternifolia essential oil to hen nutrition had a positive effect on production parameters and eggs fatty acid profile, with increased eggshell thickness (p < 0.05).

Synbiotic as eco-friendly feed additive in diets of chickens under hot climatic conditions

This study was conducted to investigate the effect of synbiotic supplementation on performance, survivability rate, microbial populations, ammonia production, liver function, and meat physicochemical properties as well as carcass characteristics in broiler chicks under hot climatic conditions. A total of 320 one-day-old Ross 308 broiler chicks were randomly assigned to 4 dietary treatments as follows: control diet without synbiotic (S0), synbiotic at 500 mg/kg for starter diet and 250 mg/kg grower diet (S1), synbiotic at 1000 mg/kg for starter diet and 500 mg/kg grower diet (S2), and synbiotic at 1500 mg/kg for starter diet and 750 mg/kg grower diet (S3). Each treatment had 10 replicate pens with 8 birds. Diets were formulated using corn, sorghum, soybean meal, corn gluten meal and sunflower oil as major ingredients to meet the nutrient requirements for starter (1 to 21 d) and grower (22 to 35 d) periods. The experiment lasted for 35 d. The results showed that body weight and body weight gain were increased (linear, P<0.01) with the increase in dietary synbiotic feeding during the trial period. In addition, the feed intake linearly increased (P < 0.001) with increasing synbiotic levels and, in turn, caused linear improvements (P < 0.001) in feed conversion values. Interestingly, E. coli, Salmonella and Shigella were decreased (P < 0.001) by supplemental synbiotic levels compared to the control group during the entire study. Furthermore, there was beneficial effects on excreta ammonia reduction (P < 0.001) by supplementation of synbiotic groups compared to control. Increasing synbiotic levels decreased (P < 0.001) drip loss and cook loss percentage of breast and leg muscles without any significant changes in pH values. Dressing, breast, and leg percentages were increased, and abdominal fat percentage was decreased by supplemental synbiotic levels. In conclusion, this investigation demonstrated that synbiotic can be used as an effective feed additive to improve productive performance, meat quality, and ammonia reduction as well as decrease microbial populations of broiler chicks in hot climatic regions.

Oregano essential oil (Origanum vulgare) to feed laying hens and its effects on animal health

This study evaluated the effect of oregano essential oil added to the feed of commercial laying hens. This research was focused on the analysis of biochemical changes linked to hepatic function, and protein and lipid metabolism. It was used 240 laying hens (59 weeks-old) distributed in a completely randomized design of six treatments (five repetitions with eight birds each). The experiments were constituted by a control treatment (CT) with the inclusion of zinc bacitracin and five treatments of oregano essential oil (OEO: 0, 50, 100, 150, and 200 mg.kg-1), respectively. After 28 days of feeding, an increase on serum levels of total proteins and globulins was observed on groups T150 and T200, as well as an increase on albumin levels on group CT. After 84 days of feeding, a significant reduction on total proteins and albumin was observed on group T200, as well as an increase in serum triglycerides. OEO at 200 mg.kg-1 increased globulin levels on day 28, which may be considered an effect in the inflammatory response, which increases serum immunoglobulins and proteins.

Effects of essential oils on performance, egg quality, nutrient digestibility and yolk fatty acid profile in laying hens

The study was conducted to investigate the effect of essential oils on performance, egg quality, nutrient digestibility and yolk fatty acid profile in laying hens. A total of 960 Lohmann laying hens aged 53 weeks were enrolled, under 4 different treatment diets supplemented with 0, 50, 100 and 150 mg/kg essential oils (Enviva EO, Dupont Nutrition Biosciences ApS, Denmark), respectively. Each treatment was replicated 8 times with 30 birds each. Birds were fed dietary treatment diets for 12 weeks (54 to 65 weeks). For data recording and analysis, a 12-week period was divided into 3 periods of 4 weeks' duration each: period 1 (54 to 57 weeks), period 2 (58 to 61 weeks), and period 3 (62 to 65 weeks). For the diet supplemented with Enviva EO, hen-day egg production and the feed conversion ratio (FCR) were significantly improved (P < 0.05) at weeks 58 to 61, and the eggshell thickness was significantly increased (P < 0.05) at week 65. However, egg production, egg weight, feed intake, FCR and other egg quality parameters (albumen height, Haugh unit, egg yolk color and eggshell strength) were not affected by the dietary treatment. In addition, compared with the control diet, protein digestibility in the 100 mg/kg Enviva EO treatment group was significantly increased (P < 0.05), and fat digestibility in the 100 and 150 mg/kg Enviva EO treatment groups was significantly decreased (P < 0.05), but Enviva EO had no effect on energy apparent digestibility. Saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) gradually decreased and polyunsaturated fatty acid (PUFA) increased with Enviva EO supplementation, but the difference was not significant. The data suggested that the supplementation of essential oils (Enviva EO) in laying hen diet did not show a significant positive effect on performance and yolk fatty acid composition but it tended to increase eggshell thickness and protein digestibility, especially at the dose of 50 mg/kg.

Safranal and its analogs inhibit Escherichia coli ATP synthase and cell growth

Safranal, a dominant component of saffron, is known to have antitumor, cytotoxic, and antibacterial properties. In this study, we examined safranal and its structural analogs-thymol, carvacrol, damascenone, cuminol, 2,6,6-trimethyl-2-cyclohexene-1,4-dione (TMCHD), 4-isopropylbenzyl bromide (IPBB), and 4-tert-butylphenol (TBP) induced inhibition of Escherichia coli membrane bound F1Fo ATP synthase. Safranal and its analogs inhibited wild-type enzyme to variable degrees. While safranal caused 100% inhibition of wild-type F1Fo ATP synthase, only about 50% inhibition occurred for αR283D mutant ATP synthase. Moreover, safranal, thymol, carvacrol, damascenone, cuminol, TMCHD, IPBB, and TBP all fully abrogated the growth of wild-type E. coli cells and had partial or no effect on the growth of null and mutant E. coli strains. Therefore, the antimicrobial properties of safranal, thymol, carvacrol, damascenone, cuminol, TMCHD, IPBB, and TBP can be linked to their binding and inhibition of ATP synthase. Total loss of growth in wild-type and partial or no growth loss in null or mutant E. coli strains demonstrates that ATP synthase is a molecular target for safranal and its structural analogs. Partial inhibition of the αArg-283 mutant enzyme establishes that αArg-283 residue is required in the polyphenol binding pocket of ATP synthase for the binding of safranal. Furthermore, partial growth loss for the null and mutant strains in the presence of inhibitors also suggests the role of other targets and residues in the process of inhibition.