Thyme oil (Thyme vulgaris L.) as a natural growth promoter for broiler chickens reared under hot climate

Impacts of dietary different levels of thyme leave powder as a natural growth promoter on growth performance, carcass characteristics, and blood indices of broilers

The objective of the present study was to ascertain the influence of thyme leaf powder (TLP) on growth rate, carcass features, and blood indicators in broiler diets as a natural antioxidant and antibiotic substitute. A fully randomized design experiment divided 264-day-old broiler chicks (Ross 308) into 4 experimental groups. Six replicates of each group, each containing 11 unsexed chicks, were created. The following were the therapies: control group without additive (basal diet); TLP1, TLP2 and TLP3: basal diet + 1, 2 and 3 g thyme leaves powder/kg diet, respectively. Results showed that TLP added at 2 or 3 g/kg of feed significantly enhanced body weight gain (except for the period from 16 to 30 d of life), feed intake (except for the period from 1 to 15 d of life), and feed conversion ratio throughout study period. Furthermore, there was a significant decrease in creatinine and alanine aminotransferase (ALT) with different TLP levels, particularly at a 3 g TLP/kg diet. Compared with the control group, the birds' 2 g TLP/kg diet included the highest levels of albumin and total protein and A/G (albumin/globulin) ratio. Furthermore, the birds fed 1 g TLP/kg feed had the lowest concentrations of low-density lipoprotein (LDL) and total cholesterol (TC). Moreover, chicks fed all treatment diets containing TLP had higher IgY concentrations than the control group. Nevertheless, the group that was fed a diet including 2 g TLP/kg had the highest IgM levels. Additionally, the superoxide dismutase activity (SOD) levels were highest in the birds fed a 1g TLP/kg diet and minimum in the birds fed the control diet. Notably, malondialdehyde (MDA) levels were maximum in birds fed a control meal and lowest in birds with a diet containing 1 g of TLP/kg. We may conclude that using TLP in broiler diets increases the birds' immunity, productivity, and overall health, especially at level 2 g of TLP/kg diet.

Effect of dietary medicinal plants on physiological responses of broiler chickens challenged with Campylobacter jejuni

BACKGROUND

Phytogenic additives would be helpful to alleviate the adverse effect of Campylobacter jejuni on the performance and physiological responses of broiler chickens.

OBJECTIVE

This experiment was carried out to investigate the effects of Echinacea purpurea (EP) and Thymbra spicata (TS) on the performance, nutrient digestibility, serum biochemistry, intestinal morphology, intestinal microbiota and immune responses of broilers challenged with C. jejuni from 0 to 42 days of age.

METHODS

A total of 240 male broiler chickens were divided into 6 groups and fed various diets: a control diet; the control diet supplemented with EP at 0.25% (EP25) or 0.50% (EP50); the control diet supplemented with TS at 0.25% (TS25) and 0.50% (TS50); or the control diet containing erythromycin at 55 ppm. Chicks were orally challenged with C. jejuni on Days 21 and 23 of age.

RESULTS

EP and TS25 diets enhanced European production efficiency factor, feed conversion ratio and digestibility of dry matter and organic matter. TS25 increased duodenal villous height (VH) and surface area on Day 42 of age. EP25 diet increased ileal VH compared to control and erythromycin diets. Diets containing certain EP25 and TS increased the Bifidobacterium population and decreased C. jejuni population on Day 39 of age. EP50 and TS50 diets increased antibody titration against Newcastle disease virus.

CONCLUSIONS

In conclusion, EP and TS dietary supplementation improved performance, microflora, intestinal morphology and immune responses in C. jejuni-challenged broilers.

Herbal extract dietary supplementation effect on growth performance and meat quality in broiler raised under two stocking densities

The number of birds or their total live weight in relation to a given area is known as stocking density; higher stocking densities will cause more stress to the birds, which may have an impact on their physiological state, productivity, carcass quality, growth performance, immunity, metabolism, and meat quality. The present study aimed to investigate the potential impact of 2 different stocking densities on growth performance, carcass characteristics, meat quality, serum, and expression of Insulin like growth factor-1 (IGF-1), muscle regulatory genes expression and serum biochemical indicators of broilers supplemented with essential oils (EO). In total, 784-day-old chicks of Ross 308 were randomly assigned into 4 different groups with 7 replicates for each: Normal feed (no essential oils [EO] added) and normal stocking as 9 bird/m2, (NSD). Normal feed (no essential oils [EO] added) and high stocking as 14 bird/m2, (HSD). Feed with essential oils (Digestarom DC® 150 g/Ton of feed) and normal stocking as 9 birds/m2, (NSD + EO). Feed with essential oils (Digestarom DC® 150 g/Ton of feed) and high stocking as 14 birds/m2, (HSD + EO) for 35 days. Bodyweight was recorded at the beginning of the trial and then at the end of each week, feed intake was recorded at the end of each week as well. A total of 28 birds (7 birds per treatment) birds were slaughtered at 35 days of age to evaluate each parameter. The HSD group had the lowest (P < 0.05) feed intake. The NSD groups showed the highest (P < 0.05) body weight gain compared to HSD groups. The HSD + EO had lower adjusted FCR (P < 0.05) compared to HSD. The legs % was the highest (P < 0.05) for NSD group, while HSD + EO had the highest (P < 0.05) Fat Pad percentage. Moreover, HSD had the highest CL%, and the lowest WHC and Warner-Bratzler shear force. For biochemical indicators, (IGF-1) was the lowest (P < 0.05) HSD group. Also, Mammalian Target of Rapamycin (mTOR) and Aspartate Aminotransferase (AST) were higher (P < 0.05) in the EO supplemented groups. Regarding gene expression, the results showed that Myogenin (MyoG) and IGF-1 were lower in HSD while MSTN was higher in the same group, (P < 0.05). In brief, essential oil supplement has improved the performance of broilers under high stocking density situation.

The role of phytogenic feed additives in stress mitigation in broiler chickens

The increase in global temperature and consumers' welfare has increased the use of phytogenic feed additives (PFA) to mitigate the negative effects of heat stress on chickens in recent years. Various bioactive compounds capable of improving the thermotolerance of broiler chickens during exposure to thermal challenges have been identified in different plant species and parts. This review is an overview of the roles of bioactive compounds of different PFA, such as polyphenols and flavonoids, antioxidants, growth-promoting and immune-modulating agents, in heat stress management in broiler chickens. Common PFA in use, particularly in tropical environments, are also discussed. An understanding of the roles of the PFA in chickens' thermotolerance could further stimulate interest in their use, thereby improving the birds' productivity and addressing consumers' concerns. This review collates the existing data on the roles of herbs in mitigating heat stress on chickens and highlights future research perspectives.

Dietary Effects of Some Plant Extracts on Laying Performance, Egg Quality, and Some Blood Parameters in Laying Hens at Different Cage Densities

This study was carried out to determine the effects of cage density and anise extract (AE), thyme extract (TE), and black cumin extract (BCE) supplementation in the diet of laying hens on laying performance, egg quality, and some blood parameters. A total of 288 Lohman White commercial hens were blocked according to the location of their cages. The four dietary treatments included a control, basal diet + 250 mg/kg of AE, basal diet + 250 mg/kg of BCE, and basal diet + 250 mg/kg of TE for 12 weeks. The cage density affected egg production (p < 0.05), feed consumption (p < 0.01), and cracked eggs (p < 0.05). Increasing the cage density caused a linear decrease in egg production and feed consumption. Compared to the control, there was a decrease in feed consumption (p < 0.01) in the plant extract groups, and in parallel, egg production decreased. An increased cage density did not affect the egg quality traits except the shell strength. The shell strength, yolk color, yolk index, albumen index, and Haught unit were significantly affected by the plant extracts. The cage density and plant extracts had a significant effect on the serum corticosterone and glucose (p < 0.01). The highest values of corticosterone and glucose were recorded for dietary TE with a cage density of 4 birds/cm2. On the other hand, the lowest values of these parameters were recorded for AE addition with a cage density of 3 birds/cm2. As a result, an increased cage density was associated with stress and depression in the feed consumption and metabolic profiles. Supplemental AE, BCE, and TE improved the laying performance and metabolic profiles.

Prophylactic influences of prebiotics on gut microbiome and immune response of heat-stressed broiler chickens

Climatic changes and elevated ambient temperature are significant environmental stressors with a negative impact on birds' physiological, immunological, and behavioral status, increasing their susceptibility to stressors and immunosuppression and consequently increasing intestinal permeability (leaky gut). Prebiotics have been utilized to stop or diminish the harmful effects of stress in chickens. We aimed to evaluate the role of mannan-oligosaccharides, and beta-D-glucan prebiotics supplements in drinking water against experimentally induced heat stress (HS) on broiler chickens and study their impact on birds' performance, gut microbiome, and immune response. A total of 120 1-day-old Ross broiler chicks were allocated into four groups (30 birds/group), and each group was subdivided into triplicates (10 birds each). The experimental groups were classified as follows; the 1st (G1) control birds, the 2nd (G2) birds exposed experimentally to HS, the 3rd (G3) birds administered prebiotics in drinking water without exposure to HS, and the 4th (G4) birds exposed to HS and administered prebiotics in drinking water. After each vaccination, blood samples and serum samples were collected to evaluate the birds' immune status. Fecal samples were also collected for the molecular evaluation of the gut microbiome based on the genetic analyses and sequencing of 16S rRNA gene. The results showed that HS has reduced the birds' performance and badly affected the birds' immune response and gut microbiome. However, the addition of prebiotics to drinking water, with or without stress, enhanced the growth rate, maintained a normal gut microbiome, and improved immune parameters. Moreover, the usage of prebiotics improved the chicken gut microbiome and alleviated the negative effect of heat stress. Administering prebiotics significantly (p < 0.05) increased the relative abundance of beneficial bacteria and eradicated pathogenic ones in the birds' gut microbiome. Prebiotics showed a positive effect on the gut microbiome and the immune status of chickens under HS in addition to their efficacy as a growth promoter.

A comprehensive review of summer savory (Satureja hortensis L.): promising ingredient for production of functional foods

This review aims to measure the different aspects of summer savory including biological activity, medicinal properties, nutritional value, food application, prospective health benefits, and its use as an additive in broiler feed. Furthermore, toxicity related to this is also overviewed. Summer savory leaves are abundant in total phenolic compounds (rosmarinic acid and flavonoids) that have a powerful antioxidant impact. Rosmarinic (α-O-caffeoyl-3,4-dihydroxy-phenyl lactic) acid has been identified in summer savory as a main component. According to phytochemical investigations, tannins, volatile oils, sterols, acids, gums, pyrocatechol, phenolic compounds, mucilage, and pyrocatechol are the primary compounds of Satureja species. Summer savory extract shows considerable biological potential in antioxidant, cytotoxic, and antibacterial assays. Regarding antioxidant activity, summer savory extract displays an inhibitory effect on lipid peroxidation. Summer savory also has Fe (III) reductive and free radical scavenging properties and contains minerals and vitamins. Summer savory has important biological properties, including antimicrobial activity and antioxidant activity, and protective effects against Jurkat T Cells, Alzheimer's disease, cancer, infection, cardiovascular diseases, diabetes, and cholesterol. The leaves and stems of this plant are employed in the food, feed, and pharmacological industries due to their antioxidant properties and substantial nutritional content. Conclusively, summer savory is widely considered beneficial for human health due to its versatile properties and medicinal use.

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.

Struggling Thermal Stress Impacts on Growth Performance and Health Status of Newly Weaned Rabbits Using Nanoemulsion of Origanum majorana Considering the Economic Efficiency of Supplementation

With the recent trend of global warming, HS-instigated diminishing could extremely jeopardize animal health, productivity, and farm profit. Marjoram essential oil (MEOE) is a worthy source of wide range phytogenic compounds that may improve heat tolerance, redox and inflammatory homeostasis, and immunity of newly weaned rabbits, specifically if included in the diets in a nano form. One hundred newly weaned rabbits were randomly distributed into four homogeneous groups. The first group (control group) included rabbits that received basal diet without supplementation. In contrast, the other three groups included rabbits that received basal diets supplemented with 200 (MEONE200), 400 (MEONE400), and 800 (MEONE800) mg MEONE/kg diet, respectively. Among MEONE-treated groups and control groups, MEONE400 group showed the highest (p < 0.001) growth performance traits, including final body weight, average daily gain, feed efficiency, and the performance index. Compared to the control, all MEONE-supplemented groups possessed lower rectal temperatures and respiration rates, recording the lowest values in the MEONE400 group. The oxidative stress biomarkers and immunoglobulins G and M were significantly improved in the MEONE400 and MEONE800 compared with the control and MEONE200 groups. The addition of MEONE (400 or 800 mg/kg) decreased the concentrations of serum interleukin-4 (p = 0.0003), interferon gamma (p = 0.0004), and tumor necrosis factor-α (p < 0.0001) but significantly elevated (p < 0.001) the activity of nitric oxide, amyloid A and lysozyme. Liver functions (lower concentrations of liver enzymes) were significantly improved in all MEONE-treated groups compared to the control group. There was a considerable significant effect of dietary supplementation of MEONE400 on economic efficiency. In conclusion, the addition of 400 mg/kg to the diets of newly weaned rabbits can be recommended as an affective intervention to mitigate the negative impacts of HS.

Effect of rosemary essential oil as nitrite substitute on quality of sausage produced using chicken fed by thymus essential oil and rapeseed oil

The objective was to determine the effect of rosemary essential oil (REO) as nitrite substitute on the physicochemical, microbiological and sensory quality of sausage from broilers fed different levels of thymus essential oil (TEO) and rapeseed oil (RO). Broiler chicks fed TEO (0, 300 and 500 ppm) and RO (1, 3 and 5%) in a 3 × 3 factorial design. Sausages were made from meat of chicken fed TEO (0 and 500 ppm) treated with REO (120 ppm), REO:nitrite (60:60 ppm), nitrite (120 ppm) or without REO and nitrite in a 2 × 4 factorial design. Results showed that TEO increased water holding capacity and pH value and decreased malondialdehyde concentration. RO (1 and 3%) × TEO (500 ppm) group had higher unsaturated to saturated fatty acids ratio in the meat. Results showed that treatments of REO (120 ppm) decreased lipid oxidation and increased pH value of meat. Sausage produced by nitrite (120 ppm) or REO:nitrite (60:60 ppm) had lower total microbial count, lightness but higher redness and yellowness. Based on the results, TEO in chicken feed decreased lipid oxidation of sausages. Furthermore, substitution at least 60 ppm nitrite with REO had more preserving effect on quality of produced sausages.

Effect of feeding bioactive compounds identified from plant extracts (4-hexylresorcinol, 7-hydroxycoumarin, and gamma-octalactone) on the productivity and quality of broiler meat

Background and Aim

Secondary bioactive compounds of medicinal plants exert anti-inflammatory, antimicrobial, antioxidant, and metabolism-modulating effects. This study aimed to investigate the effect of feeding 4-hexylresorcinol, as well as its combinations with gamma-octalactone and 7-hydroxycoumarin, on the digestibility of dietary nutrients, weight gain, and quality characteristics of the meat and liver of Arbor Acres broiler chickens.

Materials and Methods

The following feeding scheme was applied on the chickens: Control, basal diet (BD); I experimental, BD + 4-hexylresorcinol at 0.5 mg/kg of live weight per day; II experimental, BD + 4-hexylresorcinol + gamma-octalactone at 0.4 mg/kg of live weight per day; III experimental, BD + 4-hexylresorcinol + 7-hydroxycoumarin at 0.1 and 0.15 mg/kg of live weight per day; and IV experimental, BD + 4-hexylresorcinol + gamma-octalactone + 7-hydroxycoumarin at 0.05, 0.15, and 0.01 mg/kg of live weight per day.

Results

Chickens in I, II, and IV experimental groups at the age of 35 days showed superior live weight than chickens in the control group. Supplementation with all the tested additives, except the combination 4-hexylresorcinol + 7-hydroxycoumarin, significantly increased the digestibility coefficients of dietary nutrients. Supplementation with the combinations 4-hexylresorcinol + gamma-octalactone and 4-hexylresorcinol + gamma-octalactone + 7-hydroxycoumarin significantly increased the amount of fat in the pectoral muscles. However, the mass fraction of fat in the thigh muscles of broiler chickens decreased in II, III, and IV experimental groups. The pectoral muscles of broiler chickens in experimental Group IV contained small amounts of lysine, tyrosine, histidine, leucine-isoleucine, methionine, valine, proline, threonine, serine, alanine, and glycine. Supplementation with pure 4-hexylresorcinol significantly reduced the levels of lysine, phenylalanine, histidine, leucine-isoleucine, methionine, valine, proline, threonine, and alanine in the thigh muscles. However, supplementation with pure 4-hexylresorcinol significantly increased the concentrations of P, Fe, Se, Zn, and B and decreased the concentrations of I, Ni, V, Al, and Pb in the pectoral muscles. Supplementation with the combination 4-hexylresorcinol + gamma-octalactone + 7-hydroxycoumarin resulted in the accumulation of Ca, Co, Fe, Mn, Se, Zn, and Li and a decrease in the concentrations of K, Mg, and V.

Conclusion

Supplementation with all the tested additives, except the combination 4-hexylresorcinol + 7-hydroxycoumarin, exerted a positive effect on the indicators of live weight gain and dietary nutrient digestibility in broiler chickens. Supplementation with the combinations 4-hexylresorcinol + gamma-octalactone and 4-hexylresorcinol + gamma-octalactone + 7-hydroxycoumarin increased the amount of fat in the pectoral muscles but decreased it in the thigh muscles. Supplementation with all the tested additives decreased the concentrations of I in the pectoral muscles and Zn in the thigh muscles in all the experimental groups compared with those in the control group.

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

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

Microencapsulated basil oil (Ocimum basilicum Linn.) enhances growth performance, intestinal morphology, and antioxidant capacity of broiler chickens in the tropics

OBJECTIVE

Microencapsulation is a technique to improve stability, bioavailability, and controlled release of active ingredients at a target site. This experiment aimed to investigate the effects of microencapsulated basil oil (MBO) on growth performance, apparent ileal digestibility (AID), jejunal histomorphology, bacterial population as well as antioxidant capacity of broiler chickens in a tropical climate.

METHODS

A total of 288 one-day-old female broilers (Ross 308) were randomly allocated into 4 groups (6 replicates of 12 birds), based on a completely randomized design. Dietary treatments were as follows: i) basal diet (NC), ii) basal diet with avilamycin at 10 ppm (PC), iii) basal diet with free basil oil (FBO) at 500 ppm, and iv) basal diet with MBO at 500 ppm, respectively.

RESULTS

Dietary supplementation of MBO improved average daily gain, and feed conversion ratio of broilers throughout the 42-d trial period (p<0.05), whereas MBO did not affect average daily feed intake compared with NC group. The broilers fed MBO diet exhibited a greater AID of crude protein and gross energy compared with those in other groups (p<0.05). Lactobacillus spp. and Escherichia coli populations were not affected by feeding dietary treatments. Both FBO and MBO had positive effects on jejunal villus height (VH), villus height to crypt depth ratio (VH:CD) and villus surface area of broilers compared to NC and PC groups (p<0.05). Superoxide dismutase level in the duodenal mucosa of MBO group was significantly increased (p<0.01), whereas malondialdehyde level was significantly decreased (p<0.01).

CONCLUSION

Microencapsulation could be considered as a promising driver of the basil oil efficiency, consequently MBO at 500 ppm could be potentially used as a feed additive for improvement of intestinal integrity and nutrient utilization, leading to better performance of broiler chickens.

Herbal Plants Application in Organic Poultry Nutrition and Production

Background:

Medicinal plants and natural feed additives are the most important alternatives in animal production, especially broiler production, due to the ban on the use of certain antibiotics, their cost-effectiveness and harmful residual effects.

Objective:

In this mini-review article, some important medicinal herbs and plants with positive effects on organic broiler production have been highlighted.

Methods:

A literature search was conducted in Science Direct, Google, Google Scholar, Springer, Medline and PubMed.

Results:

Medicinal plants such as ginger, ginkgo, thyme, ponderosa pine, soybean, forsythia, peppermint, Chinese star anise, astragalus, mistletoe, schisandra, cumin, capsicum, garlic, hooker chives, artichoke, Borreria latifolia, zataria, pomegranate, turmeric, lingzhi, Lippia javanica, neem, oriental chaff flower, mulberry leaf, goji berry, Aloe vera, pumpkin, grape, common nettle, marigold, coriandrum, Citrus sinensis, Alisma canaliculatum, Persian hogweed, Eucommiaulmoides, bamboo leaf extract, rosemary, Morina citrifolia, chestnut, green tea, wild mint, clove, sumac, satureja, ashwagandha, Lonicera japonica, Acacia, liquorice, Artemisia annua, milk thistle, cinnamon, black cumin and etc. have positive effects on organic broiler production.

Conclusion:

Herbal medicines lead to increased body weight due to a higher feed intake and a higher feed conversion ratio, and improve antioxidant activity of broiler chickens based on their phenolic compound contents. The combination of medicinal herbal additives also has a positive impact on broiler production. In organic broiler production with the usage of herbal plants, reducing hormones, growth promoters and antibiotics should be organized as well as considering appropriate organic feed management and higher production.

Effects of supplementing diet with Thyme (Thymuas vulgaris L.) essential oil and/or selenium yeast on production performance and blood variables of broiler chickens

Background

Organic products for animals are becoming more widely accepted by consumers. Using herbal additives may lead to more healthy animal products. In this research, it is hypothesized that thyme essential oil (TEO) and/or selenium yeast (SY) would be helpful to enhance production performance in broilers.

Objective

In the current study, the effects of adding TEO and/or SY to the diet on broiler performance and blood parameters were evaluated in broiler chickens.

Methods

A total of 480 chicks were distributed in 24 cages with 20 chicks (10 males and 10 females) each and assigned to be fed four iso‐caloric and iso‐nitrogenous diets including two levels (0 and 250 mg/kg) of TEO and two levels (0 and 0.3 mg/kg) of SY in a 2 × 2 factorial arrangement with six replicates.

Results

Adding SY significantly decreased feed intake in finishing period (22–42 d) (p < 0.05). Supplementation with SY and TEO significantly decreased plasma uric acid and triglyceride levels, respectively (p < 0.05). However, neither of the supplements had any influence on the plasma glucose and albumin levels (p > 0.05). The lowest level of plasma cholesterol was detected in the birds fed the TEO‐supplemented diet (p < 0.05). Addition of SY significantly increased blood glutathione peroxidase activity (p < 0.05).

Conclusions

Dietary supplemental TEO has a favourable effect on feed intake, weight gain, and body weight values. Besides, SY may decrease blood concentration of uric acid, as well as blood glutathione peroxidase activity. An interaction is detected between TEO and SY on blood cholesterol.

Thymol and carvacrol supplementation in poultry health and performance

BACKGROUND

Thymol and carvacrol as natural essential oils and phenol compounds are components derived from some medicinal plants, such as thyme and oregano species.

OBJECTIVES

The increasing demands in organic and healthy meat and egg consumption in human society have made it necessary to consider alternative natural compounds for the replacement of chemical compounds in poultry production. The chemical compounds can remain in meat and eggs and cause complications in human health. Therefore, these natural compounds can be fed with a higher safety in poultry production with specific effects. In this regard, the role of thymol and carvacrol as natural compounds in the poultry production has been discussed in the review.

METHODS

In this study, by searching for keywords related to thymol and carvacrol in poultry production in Google Scholar database, the articles related to different aspects of the biological effects of these two phytogenes in poultry production were selected and analyzed.

RESULTS

A review of previous studies has shown that thymol and carvacrol possess a wide range of biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, modulating of immunity response and regulating of the gut microbial population. Also, in meat type chickens can promote growth and influence feed utilization. The beneficial effect of this compound was evaluated in hepatic toxicity and demonstrated as a hepatoprotective compound in chickens. Furthermore, these compounds can affect the behavior of layers and influence egg composition, eggshell thickness, and the sensory quality of eggs.

CONCLUSION

It seems that with the increasing demand for healthy protein products, these compounds can be used to improve performance as a substitute alternative for chemical compounds in healthy poultry farms.

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.

Essential Oil Delivery Route: Effect on Broiler Chicken's Growth Performance, Blood Biochemistry, Intestinal Morphology, Immune, and Antioxidant Status

Simple Summary

Much research is devoted to the search for potent alternatives to antibiotic growth promoters in the poultry industry. It is hypothesized that the efficacy of potential alternatives could be influenced by their type and the delivery strategy utilized. Consequently, this study evaluated the efficacy of a commercial essential oil blend across different delivery routes as a potent alternative to in-feed antibiotics in broiler chickens using selected biochemical, immune, and performance parameters. The results provide evidence that the successive delivery of essential oils via in ovo and in-water routes in broiler chickens offers the potential to improve broiler chicken biochemical and antioxidant status. However, the in ovo delivery of essential oil at 0.2 mL dosage (saline + essential oil, dilution ratio—2:1) suffers the limitations of reduced hatchability.

Abstract

This study evaluated the effect of an essential oil blend and its delivery routes on broiler chicken growth performance, blood biochemistry, intestinal morphology, and immune and antioxidant status. Eggs were incubated and allotted to 3 groups: non-injected group, in ovo saline group, and in ovo essential oil group. On day 18 of incubation, essential oil in saline or saline alone was injected into the amnion. At hatch, chicks were assigned to post-hatch treatment combinations (1) in ovo essential oil + in-water essential oil (in ovo + in-water EO); (2) in ovo essential oil (in ovo EO); (3) in ovo saline; (4) in-water essential oil; (5) in-feed antibiotics (Bacitracin methylene disalicylate) and (6) a negative control (NC; corn-wheat-soybean diet) in 8 replicate cages (6 birds/cage) and raised for 28 day. The in ovo EO group reduced (p < 0.05) chick length and hatchability, all groups recorded no difference in growth performance at 0–28 day. The in ovo + in-water EO treatment reduced (p < 0.05) blood creatine kinase and aspartate aminotransferase levels whilst increasing (p < 0.05) total antioxidant capacity in birds. The in ovo + in-water delivery of EO might represent a potential antibiotic reduction strategy for the poultry industry but more research is needed to address the concern of reduced hatchability.

Effect of Essential Oil of Thyme (Thymus vulgaris L.) or Increasing Levels of a Commercial Prebiotic (TechnoMOS®) on Growth Performance and Carcass Characteristics of Male Broilers

To investigate the effect of thyme (Thymus vulgaris L.) essential oil (TEO) or increasing inclusion of a prebiotic (TechnoMOS^®) on growth performance and carcass characteristics of Ross 308 broilers, 400 one-day-old male broilers (43.5 g, as mean of body weight) were placed in 20 pens (2.0 × 1.0 m, with a floor area of 0.10 m² per bird) in groups of 20, and each pen cage was assigned to a specific dietary treatment (four replicates per each one). The dietary treatments included basic diet (no additive; CTR), basic diet including 0.025%, 0.075%, or 0.125% of TechnoMOS^® (MOS025, MOS075, and MOS125, respectively), or basic diet including 0.075% thyme extract (TEO075). All dietary treatments were offered from the beginning of the study until the end of the trial. There were no effects of MOS or TEO on carcass characteristics. No significant effects of treatment on weight gain were obtained on a week-by-week basis; however, CTR birds gained less weight during the grower phase and overall compared with MOS birds. The same contrast for feed intake revealed that CTR birds had greater feed intake than MOS birds during both the grower phase and overall (492.18 g and 486.35 g, respectively). In conclusion, treated groups showed an improved feed conversion ratio.

The Effect of Adding Herbal Extracts to Drinking Water on Body Temperature, Level of Thyroid Hormones and H:L Ratio in the Blood of Broiler Chickens Exposed to Elevated Ambient Temperature

The aim of the study was to determine the effect of supplementing drinking water with extracts from lemon balm, sage and nettle on body temperature, level of thyroid hormones and the heterophil to lymphocyte (H:L) ratio in the blood of broiler chickens exposed to elevated rearing temperature. One-day-old Ross 308 chicks were divided into four groups: group I (CON) and experimental groups II (LB), II (S) and IV (N), in which, from 22 to 42 days of rearing, drinkers were supplemented with lemon balm extract, sage extract or nettle extract (2 ml/l water), respectively. In addition, at 5 weeks of growth, all the groups were exposed to elevated ambient temperature (up to 30°C) for 5 days, after which the recommended thermal conditions were reinstated. During the study, mortality, rectal temperature and radiated temperature of the broilers were monitored. Blood was collected from 10 birds per group to determine the concentration of thyroid hormones (T3 and T4) and to make blood smears. The H:L ratio was determined based on the percentage of heterophils (H) and lymphocytes (L). The herbal extracts from lemon balm, sage and nettle, added to drinking water at 2 ml/l, reduced the blood level of the thyroid hormone (triiodothyronine) and rectal temperature in the experimental broilers during the initial period of thermal stress. Chickens receiving the nettle extract were also characterised by lower radiated temperature of the unfeathered body, a lower H:L ratio in the blood during the increase in ambient temperature, and the lowest mortality percentage. It can therefore be considered that the dietary supplementation of nettle, in the form and concentration used in this study, had the most favourable effect on the physiological status of the birds (body temperature, level of thyroid hormones and H:L ratio) exposed to elevated ambient temperatures (30°C), and thus on their welfare.

Effect of supplemental glycerol monolaurate and oregano essential oil blend on the growth performance, intestinal morphology, and amino acid digestibility of broiler chickens

Background

This experiment tested the impact of the combined supplementation of glycerol monolaurate (GLM) and oregano essential oil (EO) to broiler diets. Growth performance, metabolic response, immune status, apparent ileal digestibility coefficient (AID%), and intestinal histomorphology were assessed. Three-day-old Ross-308 broilers (76.62 g ± 0.50, n = 240) were randomly allocated into 4 experimental groups (6 replicates/group and 10 chicks/replicate). Birds were fed corn-soybean meal basal diets supplemented with four levels of GLM and oregano EO blend: 0, 0.15, 0.45, and 0.75% for 35 days.

Results

During the starter period, dietary GLM and oregano EO did not show significant (P > 0.05) changes in growth performance. During the grower period, GLM and oregano EO supplemented groups showed a linear and quadratic decline in FCR. During the finisher and overall performance, a linear increase in the body weight (BW), body weight gain (BWG), the protein efficiency ratio (PER), and relative growth rate (RGR), and a linear decrease in the FCR at 0.75% dietary level of GLM and oregano EO compared to the control. The broken-line regression model showed that the optimum dietary level of GLM and oregano EO blend was 0.58% based on final BW and FCR. The 0.45% or 0.15% dietary level of supplemented additives lowered (P < 0.05) the AID% of threonine and arginine, respectively, with no change in the AID% of other assessed amino acids at all dietary levels. Muscle thickness in jejunum and ileum in all dietary supplemented groups was increased (P < 0.05); however, such increase (P < 0.05) in the duodenum was shown at 0.45 and 0.75% dietary levels. All GLM and oregano EO supplemented groups showed increased (P < 0.05) duodenal, jejunal, and ileal villus height. The 0.15 and/or 0.75% dietary levels of supplemented additives increased (P < 0.05) the ileal and duodenal crypt depth, respectively, with a decreased (P < 0.05) duodenal crypt depth at 0.15% dietary level. The goblet cell count in ileum decreased (P < 0.05) in all GLM and oregano EO supplemented groups, but this decreased count (P < 0.05) was detected in jejunum at 0.45 and 0.75% dietary levels. The GLM and oregano EO supplemented groups did not show significant (P > 0.05) changes in the assessed metabolic and immune status parameters. Economically, the total return and performance index was increased at 0.75% dietary level.

Conclusion

Better growth performance was achieved at a 0.75 % dietary level of GLM and oregano EO by improving most intestinal morphometric measures. The optimum dietary level detected was 0.58%. The lack of influence of supplemented additives on chickens' immune and metabolic responses could indicate a lack of synergy between GLM and oregano EO.

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 effects of dietary supplementation of encapsulated thyme essential oil on growth, pro-inflammatory cytokines, and serum amino acid profiles of broiler chicks challenged with Salmonella typhimurium

Salmonella Typhimurium (S. Typhimurium) causes inflammation and has adverse effects on the growth of broiler chicks. Meanwhile, plant derivations improve the growth performance and decrease inflammation, but they do not have enough stability. Encapsulation of essential oils is a new strategy for decreasing their instability. This study was conducted to investigate the effects of dietary supplementation of encapsulated Thyme essential oil (ETEO) on growth, inflammatory cytokines, and amino acid profiles of broiler chicks challenged with S. Typhimurium. Three hundred one-d-old broiler chicks were assigned into 6 groups, and 5 replications per group. The broiler chicks (3 groups) were challenged with S. Typhimurium, on day 21 and birds received basal diet (positive control), encapsulated Thyme (P-ETEO), and non-capsulated Thyme (P-NETEO), while other groups received the same diets, but under normal as a negative control, encapsulated Thyme (N-ETEO) and non-capsulated Thyme (N-NETEO). Growth performance, pro-inflammatory cytokines, and serum amino acid profiles were assessed on day 42. The challenged birds in positive control showed lower growth performance, higher concentration for inflammatory cytokines, and disturbed blood serum concentrations for amino acid profiles compared to the negative control (P<0.05). The result showed that dietary supplementation of the ETEO could improve growth performance and amino acid profiles, and also decrease inflammatory responses (P<0.05). In sum, S. Typhimurium had negative effects on growth, immunity, and inflammation, but dietary inclusion of the ETEO could decrease its negative effects.

The Oleaster (Elaeagnus angustifolia): A Comprehensive Review on Its Composition, Ethnobotanical and Prebiotic Values>

BACKGROUND

Oleaster or Elaeagnus angustifolia is a deciduous plant from Elaegnacea family and is well-known for its remedial applications.

OBJECTIVE

This paper presents a comprehensive review of the potential application of Oleaster's flour incorporated in some food products. Emphasis is given to the physicochemical, biochemical, and functional properties of Oleaster's flour.

METHODS

A comprehensive search was carried out to find publications on Oleaster's flour and its application as a prebiotic. The results of the related studies were extracted and summarized in this paper.

RESULTS

Oleaster's flour as a prebiotic ingredient enhances antioxidants, polyphenols, fiber, flavonoids, Sterols, carbohydrates, and protein content of food products.

CONCLUSION

Further advanced investigations on Oleaster and its functional ingredients revealed that these are efficacious and can be applied as a substitute source in pharmacological industries for medical applications.

Phenolic compounds as natural feed additives in poultry and swine diets: a review

Due to ban on using antibiotics in feed industry, awareness of using natural feed additives have led to a great demand. The interest of plants phenolic compounds as a potential natural antioxidant source has been considered in research community due to their predictable potential role as feed additives in poultry and swine production. However, the mode of action for their functional role and dosage recommendation in animal diets are still remain indistinct. Taking into account, the present review study highlights an outline about the mode of action of phenolic compound and their experimental uses in poultry and swine focusing on the growth performance, antioxidant function, immune function, antimicrobial role and overall health status, justified with the past findings till to date. Finally, the present review study concluded that supplementation of phenolic compounds as natural feed additives may have a role on the antioxidant, immunity, antimicrobial and overall production performance in poultry and swine.

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

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

Combined Supplementation of Nano-Zinc Oxide and Thyme Oil Improves the Nutrient Digestibility and Reproductive Fertility in the Male Californian Rabbits

Simple Summary

The present study aimed to investigate the beneficial effects of supplementing zinc oxide nanoparticles (ZnO-NPs), thyme oil (THO), or their combination on the reproductive parameters, nutrient digestibility coefficients, and some blood metabolites of male Californian rabbits. Results showed an improvement in the nutrients digestibility, liver and kidney functions, testosterone concentration, and semen characteristics (semen volume, sperm motility, vitality, and morphology). ZnO-NPs were more effective in improving the male fertility, while THO showed a marked improvement in nutrient digestibility. Therefore, the inclusion of ZnO-NPs, or THO, or both is recommended for a rabbit feeding regimen to improve the feeding profitability.

Abstract

The present study aimed to determine the effects of zinc oxide nanoparticles (ZnO-NPs), thyme oil (THO), or their combination on the nutrient digestibility coefficients, reproductive parameters, and some blood metabolites of male Californian rabbits. One hundred rabbits, 29-weeks of age (initial body weight 3.48 ± 0.08 kg) were randomly distributed into four groups, 25 rabbits each. Treatment groups were fed a control diet, a control diet supplemented with ZnO-NPs (100 mg/kg), THO (500 mg/kg), or combination of ZnO-NPs (100 mg/kg) and THO (500 mg/kg). The feeding trial lasted for 35 days. Results showed improvements in dry matter, crude protein, ether extract, and crude fiber in ZnO-NPs, THO, and their combination treated groups compared to those of control. Furthermore, semen volume, sperm motility, vitality, and morphology were significantly improved (p < 0.01) in ZnO-NPs and THO groups rather than the control. Both ZnO-NPs and THO, as either individual or combined treatments significantly improved the serum alanine amino-transferase (ALT), aspartate amino-transferase (AST), urea, and creatinine compared to the control. Moreover, serum concentrations of testosterone were significantly increased in rabbits supplemented with ZnO-NPs, THO, or their combination compared to those of control (p < 0.05). In conclusion, ZnO-NPs, THO, or their combination improved the digestibility of nutrients, liver/ kidney functions, semen characteristics, and testosterone concentration in male rabbits.

Oral administration of potato peel extract affects serum blood metabolites, liver function and ameliorating oxidative stress induced in rabbits exposed to cold stress

This study investigated the effect of potato peel extract (PPE), orally administrated to rabbits, on serum blood metabolites and ameliorating oxidative stress induced by cold stress under Egyptian winter conditions. Twenty-four bucks grouped into three treatments (8 animals per group) were used for the experiment. The animals received 1.5 ml of water orally, containing 0 (PPE0), 25 (PPE25) or 50 (PPE50) mg PPE/kg live weight. Bucks were randomly assigned into three homogenous equal groups according to the level of PPE. Treatments were applied to each animal every two days over a period of three months including one month as an adaptation period. At the 8th week of the experiment, blood samples were collected from each buck and at the end of the experiment, bucks were slaughtered, and some organs were collected and weighed. The PPE improved (p < 0.05) blood total protein, albumin, globulin and glucose. The blood concentration of total lipid, cholesterol, triglyceride, low density lipoprotein and very low-density lipoprotein (were increased (p < 0.02) in PPE rabbits. Furthermore, PPE extract doses decreased (p < 0.001) oxidant thiobarbituric reactive substance (TBARS) in both blood and liver. Other liver and blood antioxidant system enzymes such as catalase, glutathione peroxidase, and superoxide dismutase were improved (p < 0.005) by PPE supplementation. Overall, oral administration of PPE up to 50 mg/kg live weight can have positive effects on rabbit health under cold stress.

Research Note: Phytobiotics modulate the expression profile of circulating inflammasome and cyto(chemo)kine in whole blood of broilers exposed to cyclic heat stress

Heat stress (HS) is a critical concern to the poultry industry as it affects both productivity and well-being. Various managerial and nutritional strategies have been proposed to mitigate the negative effects of HS in chickens, with plant-based additives showing promise. Recently, we reported the positive effect of a phytogenic feed additive (PFA) on growth performance in HS birds. Owing to the antioxidant nature of these compounds, we sought to further explore the effect of PFA on whole blood circulating chemokines, cytokines, and inflammasomes in HS broilers. Broilers (600 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to 2 environmental conditions (12 h cyclic heat stress, HS, 35°C vs. thermoneutral condition [TN], 24°C) and fed 3 diets (control, PFA-C 250 ppm, PFA-C 400 ppm) in a 2 × 3 factorial design. After 21 d of cyclic HS, blood samples were collected for target gene expression analysis. HS upregulated the expression of superoxide dismutase 1 (SOD1) and downregulated glutathione peroxidase-3 (GPX-3), and there was diet × temperature interaction for SOD2, GPX-1, and GPX-3, where gene expression was increased by PFA-C250 during HS but was unchanged for PFA-C400. Plasma total antioxidant capacity (TAC) and malondialdehyde (MDA) content were increased by HS. Gene expression of interleukin-18 (IL-18) was decreased by HS, without further effect of PFA. HS increased tumor necrosis factor α (TNFα), but this effect was mitigated by PFA-C400. C-C motif chemokine ligands 4 and 20 (CCL4 and CCL20) showed a similar pattern to TNFα, with PFA-C400 ameliorating the negative effect of HS. The nucleotide-binding, leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome was decreased by HS and further lowered by PFA-C400, but the nucleotide-binding oligomerization domain, leucine-rich repeat, and CARD domain containing 3 (NLRC3) and nucleotide-binding, leucine-rich repeat containing X1 (NLRX1) inflammasomes were increased by PFA under TN conditions, with no effects of HS. Heat shock proteins (HSP) and heat shock factors (HSF) were unaffected by PFA or HS. Together these data indicate that gene expression of circulating inflammatory factors are dysregulated during HS, and supplemental dietary PFA may be protective.

Productive and Physiological Response of Male Rabbits to Dietary Supplementation with Thyme Essential Oil

Simple Summary

The present study was carried out to compare the potential effects of the levels of thyme essential oil on the productive performance and serum metabolic profile of male rabbits. Rabbits were assigned to five dietary treatments including a basal diet as a negative control, a basal diet supplemented with an antibiotic as a positive control, and a basal diet supplemented with 60, 120, or 180 mg/kg of thyme essential oil. The main results showed that the levels of thyme essential oil contributed to the improvement of productive and the physiological response compared with the negative and positive control of male rabbits.

Abstract

The present study aimed at assessing the efficiency of thyme essential oil (TEO) as an alternative to antibiotics for improving the productive performance and serum metabolic profile of male rabbits. A total of one hundred and fifty 70-day-old male Californian rabbits were assigned to five dietary treatments, including a basal diet as a negative control (NC), a basal diet supplemented with an antibiotic as a positive control (PC), and a basal diet supplemented with 60, 120, or 180 mg/kg of TEO. The experiment period lasted for 60 days. Supplementation of TEO levels significantly (P < 0.01) increased daily body weight gain and improved feed conversion ratio of male Californian rabbits compared to NC and PC groups. Similarly, the TEO remarkably enhanced the semen characteristics of rabbits compared to NC and PC groups. Supplementation of TEO significantly decreased aspartate transaminase, alanine transaminase, urea, and creatinine compared with NC and PC groups. Supplementation with TEO increased serum testosterone concentration compared to NC and PC treatments. Our data demonstrate that TEO levels up to 180 mg/kg can play a major role as an alternative to dietary antibiotics, in improving the productive performance, semen quality, testosterone levels, and the kidney and liver functions in California male rabbits.

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.

Challenges to the Poultry Industry: Current Perspectives and Strategic Future After the COVID-19 Outbreak

Poultry immunity, health, and production are several factors that challenge the future growth of the poultry industry. Consumer confidence, product quality and safety, types of products, and the emergence and re-emergence of diseases will continue to be major challenges to the current situation and the strategic future of the industry. Foodborne and zoonotic diseases are strictly linked with poultry. Eradication, elimination, and/or control of foodborne and zoonotic pathogens present a major challenge to the poultry industry. In addition, the public health hazards from consuming foods with high antibiotic residues will remain a critical issue. The theory of poultry production described in this review will not be limited to considering disease control. Rather, it will also incorporate the interconnection of the animals' health, welfare, and immunity. It is essential to know that chickens are not susceptible to intranasal infection by the SARS-CoV-2 (COVID-19) virus. Nevertheless, the COVID-19 pandemic will affect poultry consumption, transport, and the economics of poultry farming. It will also take into consideration economic, ethical, social dimensions, and the sustenance of the accomplishment of high environmental security. Stockholders, veterinarians, farmers, and all the partners of the chain of poultry production need to be more involved in the current situation and the strategic future of the industry to fulfill human demands and ensure sustainable agriculture. Thus, the present review explores these important tasks.

Chitosan oligosaccharide as an effective feed additive to maintain growth performance, meat quality, muscle glycolytic metabolism, and oxidative status in yellow-feather broilers under heat stress

This study investigated the effects of dietary chitosan oligosaccharides (COS) supplementation on growth performance; corticosterone, growth hormone, and insulin-like growth factor-1 concentration; relative organ weight; liver function; meat quality; muscle glycolytic metabolism; and oxidative status in yellow-feather broilers under heat stress. A total of 108 35-day-old Chinese yellow-feather broilers (BW, 470.31 ± 13.15 g) was randomly allocated to 3 dietary treatments as follow: control group, basal diet and raised under normal temperature (24°C); HS group, basal diet and raised under cycle heat stress (34°C from 10:00 to 18:00 and 24°C for the rest time); and HSC group, basal diet with 200 mg/kg COS supplementation and raised under cycle heat stress. Each treatment had 6 replication pens and 6 broilers per pen. Results indicated that heat stress decreased ADG, ADFI, gain:feed ratio, the relative weight of thymus, bursa of Fabricius, pancreas, proventriculus, gizzard, and liver, growth hormone concentration, pH_24h, muscle glycogen content, muscle superoxide dismutase and glutathione peroxidase activity, as well as increased corticosterone, alanine aminotransferase and aspartate aminotransferase level, cooking loss, muscle lactate and malondialdehyde content. Compared with the HS group, broilers in the HSC group had higher ADG, the relative weight of thymus, bursa of Fabricius, and liver, growth hormone concentration, pH_24h, muscle glycogen content, muscle superoxide dismutase and glutathione peroxidase activity, and lower serum corticosterone, alanine aminotransferase and aspartate aminotransferase level, cooking loss, and muscle lactate and malondialdehyde content. In conclusion, the results suggested that COS could be used as an effective feed additive to maintain growth performance, liver function, meat quality, muscle glycolytic metabolism, and oxidative status of yellow-feather broilers under heat stress. The improved meat quality is possibly through reducing muscle glycolysis metabolism and improving muscle oxidative status by dietary COS supplementation in broilers under heat stress.

Dietary Supplementation with Natural Extracts Mixture: Effects on Reproductive Performances, Blood Biochemical and Antioxidant Parameters in Rabbit Does

The present study evaluates the effects of natural extracts on reproductive performance, haematochemical parameters, and antioxidant status of rabbit does. A total of sixty New Zealand White second parity does were divided into three groups: the first group was fed a control diet (CON), the second (T1) and the third groups (T2) were fed the same diet supplemented with prebiotic polysaccharides from brown seaweeds (Laminaria spp.) plus phenolic acid, hydroxycinnamic acids, tannins, and flavonoids from plant extracts (0.3% and 0.6%, respectively). The trial was conducted for two consecutive reproductive cycles (75 days). Reproductive performance was recorded. Blood samples were collected before the first insemination, 10 d after the first kindling, and 10 d after the second one. At the first reproductive cycle, productive parameters were negatively affected (P<0.05) by a high dosage of the dietary supplement (T2 group). At the second reproductive cycle, no differences (P>0.05) between dietary treatments on reproductive and productive performances were observed. Bilirubin was affected by dietary treatment (P<0.001) and decreased in relation to sampling time (P<0.001). The HDL cholesterol decreased by dietary treatment (P<0.01). All the plasma antioxidant markers were positively affected (P<0.001) by dietary supplementation and sampling time. No previous study has reported the effects of brown seaweeds and polyphenols on rabbit does and the present data shows that this natural extract supplement improved the antioxidant status of rabbit does.

Herbs as thermoregulatory agents in poultry: An overview

The adverse effect of increased environmental temperature during summer season on avian industry has received great global concern. High temperature leads to severe economic loss in poultry production, because it is considered as valuable stress factor. Several practical methods were used to alleviate the adverse impact of increased temperature; among them were dietary modifications. So, several types of herbs are supplemented to reduce the deleterious influences of thermal stress altitudes in various animals, and even to prevent their adverse impacts. Therefore, sustainable supports for dietary modification based on herbs supplementations are largely needed, particularly when consider the additional advantages of herbs such as availability, actual efficiency, low cost, as well as their free from residual impact and antibiotic resistance. Numerous types of herbs were concluded to their efficient properties by poultry breeders to overcome a variety of the harmful effects of high ambient temperature. The present article deliberates the different practical applications of several members of the traditional herbal wealth to improve the general health state of poultry particularly as thermoregulatory and immunomodulatory agents, and for countering the heat stress-associated immunosuppressive effects. Additionally, the antioxidant activity of herbal growth promoters and their influence on improvement of production performances were a special aim of this review. The reported information will be helpful for improvement of general production and health status of birds reared under the heat stress via enhancement of immune response and stress tolerance, and popularizes usage of herbs amongst poultry producers.

Administration of ginger and/or thyme has ameliorative effects on liver and kidney functions of V-line rabbits: Histological and biochemical studies

This study was conducted to evaluate the effect of Zingiber officinale and Thymus vulgaris aqueous extracts as a natural antioxidant on liver and kidney functions and antioxidant status of growing rabbits. A total of 24 V-line male rabbits, 3 months old, 1.465 ± 0.12 kg average body weight (BW) were used in a complete randomized design. The rabbits were weighed individually and assigned randomly to four groups (6 animals/each). The first group (G1) was taken fresh water and served as control, rabbits of the second group (G2) were taken 100 mg/kg BW in drinking water of the Z. officinale aqueous extract daily. The third group (G3) was taken 50 mg/kg BW in drinking water of the T. vulgaris aqueous extract daily and the fourth group (G4) was taken 100 mg/kg BW of the Z. officinale aqueous extract plus 50 mg/kg BW of the T. vulgaris aqueous extract in drinking water daily. The oral administration of ginger and/or thyme aqueous extracts increased (p < .001) serum protein profile compared with control group. Moreover, results of group 2 showed significant (p < .001) decrease in cholesterol, triglyceride and very low-density lipoprotein cholesterol compared with group 3 and 4. Serum urea, uric acid and creatinine levels were significantly (p < .001) decreased in treated groups compared with control group. Oral administration of ginger and/or thyme aqueous extracts to growing rabbits increased (p < .001) total antioxidant capacity and glutathione content and the activity of superoxide dismutase, catalase and glutathione-S-transferase compared with the control group. In conclusion, the current study showed that oral administration of ginger and thyme aqueous extracts to growing rabbits showed no adverse effects on liver and kidney function parameters, histological structures and improved antioxidant status.

The Anti-Oxidation and Mechanism of Essential Oil of Paederia scandens in the NAFLD Model of Chicken

Simple Summary

The essential oil of Paederia scandens can remedy non-alcoholic fatty liver disease of chicken, but the mechanisms remain unclear. In this study, proteomics technology was used to declare the anti-non-alcoholic fatty liver disease mechanism of Paederia scandens essential oil. The results show that the essential oil of Paederia scandens significant decreased the oxidative stress of non-alcoholic fatty liver disease in chicken, which was mainly due to the center regulation protein of HSP7C being significantly inhibited.

Abstract

The aim of the study is to determine the underlying pathogenic mechanisms of oxidative stress and detect the anti-oxidative target of essential oil of Paederia scandens in non-alcoholic fatty liver disease (NAFLD). Chicken NAFLD was modeled by feeding with a high-capacity diet and Paederia scandens essential oil was used to treat the disease. The levels of hepatic reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and the differential proteins and network of protein–protein interactions were investigated in model and drug-treated groups. The results showed that essential oil of Paederia scandens down regulated the hepatic ROS and MDA level significantly (p < 0.05 and 0.01, respectively). The heat shock cognate 71 kDa protein (HSP7C) was down regulated significantly, which was in the center of the network and interacted with 22 other proteins. The results showed that oxidative stress played an important role in the pathogenesis of chicken NAFLD. The essential oil of Paederia scandens showed good anti-oxidation activity by down regulating the HSP7C protein, which can be used as a potential therapeutic target in chicken NAFLD.

Effect of dietary nutmeg oil on heat-stress tolerance-related parameters in Korean native chicken reared under hot temperature

This study investigated the effect of dietary nutmeg oil (NO) on growth performance, blood parameters, lipid peroxidation and heat shock protein (HSP) 70 expression in Korean native chicken (KNC) reared under hot temperature. We allocated 273 meat-type KNCs (Hanhyup-3, 4-week-old, body weight [BW] = 539.93 ± 1.75 g) to the following three treatments with seven replicate pens (13 birds/pen) per treatment. Three treatment diets were as follows: (a) Control, basal diet without NO supplementation; (b) NO 250; and (c) NO 500, basal diet supplemented with 250 and 500 ppm NO respectively. Diets and water were provided ad libitum throughout the 6-week feeding trial. During overall period (0-6 weeks), no differences (p > 0.05) were observed in BW gain (BWG), feed intake (FI) and feed conversion rate (FCR) among treatments. However, the FI at 0-3 weeks decreased (p < 0.05) quadratically with increasing NO levels. Most blood parameters did not differ (p > 0.05) among treatments, although the monocyte level of the NO 500 group was considerably lower (p > 0.05) than that of the other groups. Furthermore, dietary NO did not affect serum triglyceride, cholesterol, total protein, albumin, calcium, phosphorus and alanine aminotransferase (ALT) levels (p > 0.05); however, it linearly decreased serum aspartate aminotransferase (AST) level (p < 0.05). Additionally, serum malondialdehyde (MDA) concentration decreased (p < 0.05) and heart MDA concentration was lower (p = 0.08) with increasing dietary NO supplementation. After a 3-hr heat (35°C) challenge, the rectal temperature (RT) reduced (p < 0.05) linearly with increasing NO levels. Dietary NO did not affect liver HSP70 (p > 0.05) gene expression. In conclusion, NO potentially enhanced the ability of chickens to alleviate heat stress. Furthermore, our findings suggest that lipid oxidation inhibition by dietary NO likely mediated the enhanced heat-stress tolerance of the chickens.

Summer Savory (Satureja hortensis L.) Extract as Natural Feed Additive in Broilers: Effects on Growth, Plasma Constituents, Immune Response, and Ileal Microflora

Simple Summary

The growth-promoting effect of many herbs and their extracts in poultry has been reported in literature. Therefore, the objective of this feeding trial was to determine the effect of different levels of summer savory (Satureja hortensis L.) extract in diet on broilers performance, immune response, hematology, and microbiota. Based on findings, dietary supplementation with summer savory extract, as natural feed additive, sustained growth traits and improved the feed efficiency and health status of broilers.

Abstract

This study investigated the effects of summer savory (Satureja hortensis L.) extract (SSE) on growth, plasma constituents, immune response, and gut microbiota of broiler chickens. A total of 300 day-old broiler chicks were randomly assigned to five dietary treatments containing five replicates of 12 birds each. The treatments consisted of a controldiet without feed additive and experimental diets supplemented with four levels of SSE (100, 200, 300, and 400 mg/kg, respectively). Results showed no significant effect of SSE supplementation on broiler body weight gain (p > 0.05), but feed conversion ratio was significantly (p < 0.05) improved when fed 400 mg/kg SSE compared to control. Most of the blood parameters and immune response criteria studied were improved (p < 0.05) by SSE supplementation. There was no dietary effect on Lactobacilli count (p > 0.05); conversely, Escherichia coli count was reduced and the Lactobacilli/E. coli ratio improved with SSE (p < 0.05). Based on our findings, it was concluded that supplementation of the diet with SSE up to 400 mg/kg sustained growth traits and improved the feed efficiency and health status of broilers. However, more research is needed on this subject in order to better understand the mode of action of the extract used.

Performance, haemato-biochemical indices and antioxidant status of growing rabbits fed on diets supplemented with Mucuna pruriens leaf meal

<p>The effects of dietary <em>Mucuna pruriens</em> leaf meal (MLM) supplementation on rabbits’ performance, haemato-biochemical indices and antioxidant status outside their thermal neutrality zone (21 to 25°C) were evaluated. One hundred and twenty 35-d old crossbreed (Chinchilla×New Zealand) rabbits weighing 694±5 g were allotted to 4 treatments (30 rabbits/treatment; 3 rabbits/replicate). A basal diet (crude protein: 16.9%, crude fibre: 17.6%, digestible energy: 2671 kcal/kg) was divided into 4 equal portions i.e. diets 1, 2, 3 and 4, supplemented with 0, 4, 8 and 12 g MLM/kg, respectively, and pelleted. The average body weight in rabbits fed on diets 3 and 4 was higher compared to those fed on diet 1 (control) at 91 d of age (+228 and +262 g, respectively; P=0.01). Within 35 to 91 d, the average daily weight gain in rabbits fed on diets 3 and 4 was higher compared to those fed on the control diet (+4.1and +4.8 g/d, respectively; P=0.01). The dressing-out percentage of rabbits fed on diets 3 and 4 increased (P=0.05) compared to those fed the control diet. At 63 d and 91 d of age, the white blood cell level of rabbits fed on diet 4 increased significantly compared to those fed the control diet (+5.05×10⁹ and +5.32×10⁹/L, respectively). At 63 and 91 d of age, the cholesterol level of rabbits fed on diets 3 (–1.0 and –1.16 mmol/L, respectively) and 4 (–1.10 and –1.21 mmol/L, respectively), were significantly lower compared to those fed on the control diet. The aspartate aminotransferase (AST) concentration in rabbits fed on diet 4 was reduced compared to those on control diet at 63 d of age (–33.68 IU/L; P=0.02). At 63 d and 91 d of age, compared to control, the activities of glutathione peroxidase in rabbits fed on diets 3 (+35.77 and +49.09 mg protein, respectively) and 4 (+54.52 and +55.02 mg protein, respectively) increased significantly, while catalase activities in rabbits fed diet 4 (+217.7 and +209.5 mg/g, respectively) also increased significantly. It could be concluded that dietary MLM supplementation enhanced the rabbits’ performance, reduced serum AST and cholesterol and improved the antioxidant status.</p>

Thyme oil inclusion levels in a rabbit ration: Evaluation of productive performance, carcass criteria and meat quality under hot environmental conditions

The aim of this study was to determine the impact of thyme essential oil supplementation in rabbit rations on performance, carcass criteria, and meat quality under hot environmental conditions. A total of 75, 4-week-old Californian male rabbits were assigned to 5 dietary treatments until 12 weeks of age. The rabbits were reared in an open house system (38 °C average ambient temperature and 26% to 35% relative humidity). Treatments were as follows: unsupplemented standard ration, negative control (CON); standard ration supplemented with 1.50 g/kg olive oil as carrier, positive control (POS); POS + 50 mg/kg thyme oil (TO1); POS + 100 mg/kg thyme oil (TO2); and POS + 150 mg/kg thyme oil (TO3). Dietary thyme oil up to 150 mg/kg improved (P < 0.001) feed intake and growth performance in comparison to CON. The highest average daily gain and most efficient feed conversion ratio (linear, P < 0.001 and quadratic, P < 0.001) were found for TO1 followed by TO2, TO3 and POS, respectively. The incorporation of thyme oil improved (P < 0.001) carcass criteria and decreased (P < 0.001) perirenal and scapular fat without any side effects on internal organs. Notably, the water holding capacity of rabbit meat was greater (P < 0.001), and the lipid oxidation was lower (P < 0.01) in rabbits fed treated rations compared with CON. Differences were also recorded in oxymyoglobin and metmyoglobin contents in rabbit meat among treatments. In conclusion, thyme oil of a specified composition and to be added to a rabbit ration up to 100 mg/kg using 1.50 g/kg olive oil as a carrier can be used as an efficient feed additive for improving productive performance of rabbits under hot environmental conditions.