Use of active substances of plant origin in chicken diets based on maize and locally grown cereals

Supplemental effects of different production methods of pine needle additives on growth performance, intestinal environment, meat quality and serum of broiler chickens

OBJECTIVE

Pine needles are rich in many nutrients and exhibit antibacterial and antioxidant biological activities; however, the effects of different production methods of pine needle additives on the growth performance and intestinal flora of broiler chickens are not known.

METHODS

Normal diets were supplemented with pine needle fermentation juice (PNF), pine needle soaking juice (PNS), or pine needle powder (PNP), and the associated effects on growth performance, relative organ weights, intestinal development, intestinal histological morphology, intestinal flora, meat quality, and serum indicators in broiler chickens were observed.

RESULTS

The results showed that PNF, PNS, and PNP all significantly improved feed utilisation and promoted the growth and development of broilers. All three additives also significantly improved the structure of the intestinal flora, specifically increasing the diversity of bacteria; increasing the abundance of beneficial bacteria, such as Faecalibacterium, Rikenella, and Blautia; and decreasing the abundance of harmful bacteria, such as Staphylococcus. The antioxidant properties of pine needles were also found to intensify lipid metabolic reactions in the blood, thus leading to lower triglycerides and total cholesterol. Meanwhile, high doses of PNF reduced jejunum and ileum weights and also increased meat yellowness. Lastly, none of PNF, PNS, or PNP had an effect on relative organ weights or intestinal histological morphology.

CONCLUSION

The addition of pine needles to the diet of broiler chickens can effectively promote their growth performance as well as improve their intestinal flora and serum status without side effects; in particular, the dose of 0.2% of either PNF and PNS is expected to have the capacity to replace growth-promoting antibiotics as diet additives.

Impact of Nanoencapsulated Rosemary Essential Oil as a Novel Feed Additive on Growth Performance, Nutrient Utilization, Carcass Traits, Meat Quality and Gene Expression of Broiler Chicken

This study evaluated the effect of free and nanoencapsulated rosemary essential oil (REO) as an antibiotic alternative in broiler diets on growth performance, nutrient digestibility, carcass traits, meat quality and gene expression. Four hundred twenty day-old commercial broiler chicks (VENCOBB) were randomly allocated to seven dietary treatments, each having four replicates of fifteen chicks. The dietary treatments comprised control (CON) fed a basal diet only, AB (basal diet + 10 mg enramycin/kg), CS (basal diet + 150 mg chitosan nanoparticles/kg), REOF100 and REOF200 (basal diet + 100 mg and 200 mg free REO/kg, respectively), and REON100 and REON200 (basal diet + 100 mg and 200 mg nanoencapsulated REO/kg, respectively). Overall (7-42 d), REON200 showed the highest (p < 0.001) body weight gain (1899 g/bird) and CON had the lowest gain (1742 g/bird), while the CS, REOF100 and REOF200 groups had a similar gain, but lower than that of the AB and REON100 groups. Feed intake was not affected by dietary treatments. Overall, the feed efficiency increased (p = 0.001) by 8.47% in the REON200 group and 6.21% in the AB and REON100 groups compared with the CON. Supplementation of REO improved (p < 0.05) dry matter and crude protein digestibility, with the highest values in REON100 and REON200. Ether extract, crude fiber, calcium and phosphorus digestibility values showed no difference among the groups. The dressing, breast, thigh % increased (p < 0.05) and abdominal fat % decreased (p < 0.001) more in the REON200 group than with other treatments and CON. In breast meat quality, water holding capacity and extract reserve volume increased (p < 0.05) while drip loss and cholesterol content decreased (p < 0.05) in REON100 and REON200. No change was observed in the breast meat color among dietary treatments and CON. The REON100 and REON200 groups had reduced (p < 0.05) meat lipid peroxidation as depicted by the decreased levels of TBARS, free fatty acids and peroxide value compared to other treatments and CON. The expression of the Mucin 2, PepT1 and IL-10 genes was upregulated (p < 0.001) and TNF-α downregulated (p < 0.001) by dietary addition of REO particularly in the nanoencapsulated form compared with the CON. In conclusion, nanoencapsulated REO, especially at 200 mg/kg diet, showed promising results as an antibiotic alternative in improving the performance, nutrient digestibility, carcass traits, meat quality and upregulation of growth and anti-inflammatory genes.

Assessing the potential of phytogenic feed additives: A comprehensive review on their effectiveness as a potent dietary enhancement for nonruminant in swine and poultry

Phytogenic feed additives (PFAs) often referred to as phytobiotics or botanical feed additives, are natural compounds derived from various plants, herbs, spices and other botanical sources. These feed additives are intended to serve a variety of purposes, including an immune system regulator, an antimicrobial, an antimutagenic, an antioxidant and a growth promoter. They are composed of bioactive compounds extracted from plants, including essential oils, polyphenols, terpenoids and flavonoids. They are mostly utilized as substitute antibiotic growth promoters in nonruminant (swine and poultry) livestock production, owing to the prohibition of antibiotic usage in the feed industry. It has been thoroughly examined to ascertain their impact on intestinal health and activity, correlation with animals' effective health and well-being, productivity, food security and environmental impact. The potential uses of these feed additives depend on the properties of herbs, the comprehension of their principal and secondary components, knowledge of their mechanisms of action, the safety of animals and the products they produce. They are gaining recognition as effective and sustainable tools for promoting animal health and performance while reducing the reliance on antibiotics in nonruminant nutrition. Their natural origins, multifaceted benefits and alignment with consumer preferences make them a valuable addition to modern animal farming process. However, because of their inconsistent effects and inadequate knowledge of the mechanisms of action, their usage as a feed additive has been limited. This review offers a comprehensive assessment of the applications of PFAs as an effective feed supplement in swine and poultry nutrition. In summary, this comprehensive review provides current knowledge, identifies gaps in research and emphasizes the potential of phytogenic additives to foster sustainable and healthier livestock production systems while addressing the global concerns associated with antibiotic use in livestock farming.

Enhancing effect of oregano essential oil and Bacillus subtilis on broiler immune function, intestinal morphology and growth performance

The present study evaluated the effect of two categories of feed additives on chicken performance through immunological and intestinal histo-morphometric measurements. A total of 150 one-day-old male broiler chicks (Cobb) were randomly assigned to three groups. Group I received a non-supplemented basal diet. While groups II and III were treated with a basal diet supplemented with oregano essential oil (OEO) and Bacillus subtilis, respectively, in water for 28 days. Blood samples were taken at 6, 18 and 28 days for hematological analysis, phagocytosis, lymphocyte proliferation and measuring antibody responses. Additionally, growth performance indices were recorded weekly. The results showed that groups supplemented with OEO and B. subtilis improved growth performance expressed by a significant increase in weight gain (P < 0.05), with a significant reduction (P < 0.05) in feed conversion ratio (FCR). Hematological findings indicated a significant increase in blood parameters as well as a significant increase in phagocytic % & phagocytic index at all time points with a greater probiotic effect. On the other hand, OEO produced a significant increase in lymphocyte proliferation at 18 & 28 days. Humoral immunity revealed a significant increase in serum antibody titer phytobiotic & probiotic-fed groups at time points of 18 & 28 days with a superior phytobiotic effect. The histological examination showed a significant increase in villi length, villi width, crypt depth & V/C ratio. In conclusion, these results indicated positive effects of B. subtilis & OEO on both growth and immunity and could be considered effective alternatives to the antibiotic.

Does dietary supplementation with lettuce seed oil enhance broiler performance, immunity, lipid profile, liver and kidney functions, antioxidant parameters, and intestinal microbiota?

The aim of this research was to evaluate the influence of lettuce seed oil (LSO) on the performance, carcass yield, kidney and liver indices, immunity, lipid profile, and cecal microbiota of fattening chicks. A total of 200, 7-day-old Cobb-500 were distributed into 5 experimental groups; each group contained 5 replicates with 8 birds each. The first group 1) the basal diet (only); 2) the basal diet plus lettuce seed oil (0.50 mL/kg); 3) the basal diet plus lettuce seed oil (1.00 mL/kg); 4) the basal diet plus lettuce seed oil (1.50 mL/kg); and 5) the basal diet plus lettuce seed oil (2.00 mL/kg). No significant effect was observed on growth performance, carcass traits, or kidney function at any level of oil. But, liver function was significantly affected due to LSO levels. Serum lipid profiles (total cholesterol-TC, triglyceride-TG, low-density lipoprotein-LDL, and very low-density lipoprotein-VLDL) were significantly reduced by using LSO levels compared to the control group. Dietary LSO significantly increased immunological and antioxidant parameters, except for malondialdehyde-MDA, which was reduced. On the other hand, the cecal microbiota was significantly improved by LSO additives. It was concluded that the dietary supplementation of LSO had beneficial effects on liver and kidney functions, lipid profile, immunity, antioxidant parameters, and the bacteriology of fattening chicks.

Influence of hot red pepper oil in broiler diets on blood, antioxidant, immunological parameters and intestinal bacteria counts

The present study aimed to examine the impacts of supplementing hot red pepper oil (HRPO) to broiler diets. One hundred and twenty Arbor Acres chicks were divided randomly into four experimental groups as three supplementation levels of HRPO (0.25, 0.5 and 1.0 mL/kg diet) and the control group. Results showed that HRPO supplementation exhibited significantly (p < 0.001) higher red blood cells (RBCs) count, hemoglobin (Hb) and packed cells volume (PCV) percentage, while insignificant effects were shown for white blood cells (WBCs) count or its differentiation. Diets supplemented with different levels of HRPO influenced significantly (p < 0.001) the total protein (TP), albumin (Alb) and glucose (Glo) values of the studied birds. Results also indicated that different levels of HRPO supplementations significantly (p < 0.01) decreased total lipid, triglycerides (Trig), cholesterol (Cho) and low-density lipoprotein (LDL), but did not affect high density lipoprotein (HDL) values. Data revealed that supplementing broiler diets with different levels of HRPO enhanced their liver function. The bactericidal activity index was significantly increased (p < 0.02) compared with control. HRPO supplemented groups had beneficial effects (p < 0.02) on cecal microbiota count. It could be concluded that dietary HRPO supplementation could improve the general internal health status of Arbor Acres broiler chicks.

Comparative effects of medium-chain fatty acids or phytobiotics-based feed additives on performance, caecum microbiota, volatile fatty acid production and intestinal morphology of broilers

Antibiotic growth promoters have been utilized in broiler nutrition to alleviate the negative effects of the pathogenic microbes to promote performance. However, after the prohibition of antibiotics because of the increasing disclosure related to public health issues, various products have been developed as alternatives. This study was carried out to determine the effects of medium-chain fatty acids (MCFAs) or phytobiotics (essential oils [EOs] and alkaloids [ALKs]), blended feed additives on the growth performance, jejunum histomorphology, and cecal microbiota of broiler chickens. A total of 765 male Ross 308 chicks were randomly distributed into 5 experimental groups, each having 9 replicates with 17 chicks. The experimental procedures were as follows: a control group without supplementation (T1); control group+ MCFAs and EOs blend (T2); control group+ different EOs blend (T3); control group+ ALK sanguinarine (T4); and control group+ EOs and ALK piperine mixture (T5). The results showed that, broilers fed with MCFAs blended with EOs had significantly greater body weight gain during overall period in comparision to the control and T3 groups. Further, only MCFAs blended with EOs group significantly improved jejnum morphology in comparison with the control group (p ≤ 0.05). Besides, the MCFAs blended with EOs group significantly elevated propionate, acetate and butyrate concentration, and decreased the concentration of branch chain fatty acids in caecum (p ≤ 0.05). The results indicated that, the combination of MCFAs and EOs seems to have improvement effects and could be preferred as an efficient feed additive in broiler production.

Cutting-edge knowledge on the roles of phytobiotics and their proposed modes of action in swine

With the ban on antibiotics in the swine industry, the exploration of alternative options has highlighted phytobiotics as a promising substitute for antibiotic growth promoters, aiming to foster a more sustainable swine industry. Phytobiotics are non-nutritive natural bioactive components derived from plants that offer numerous health benefits. They exhibit antioxidative, antimicrobial, and anti-inflammatory effects. Phytobiotics can be utilized in various forms, including solid, dried, ground, or as extracts, either in crude or concentrated form. They are characterized by low residual levels, a lack of resistance development, and minimal adverse effects. These qualities make phytobiotics an attractive choice for enhancing health and productivity in swine, presenting them as a viable alternative to antibiotics. While there is a general understanding of the effects of phytobiotics, there is still a need for detailed information regarding their effectiveness and mechanisms of action in practical settings. Therefore, the purpose of this mini review was to summarize the current knowledge supporting the roles of phytobiotics and their proposed modes of action, with a specific focus on swine.

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.

The Effect of Encapsulated Propyl Propane Thiosulfonate (PTSO) on Apparent Ileal Digestibility and Productive Performance in Broiler Chickens

This study analyzed the effects of different dietary doses of encapsulated propyl propane thiosulfonate (Pe-PTSO) on the apparent ileal digestibility (AID) of nutrients and productive performance in broilers. A total of 100 one-day-old Cobb 500 were housed in battery cages for 20 days. At 10 days of age, the birds were assigned to one of five diets: negative control (P0), 250 mg/kg of Pe-PTSO (P250), 500 mg/kg of Pe-PTSO (P500), 750 mg/kg of Pe-PTSO (P750), and positive control, nicarbazin-narasin (ION). Titanium dioxide was the external marker, which was added to the diets from day 17 to 20. In the birds fed the P250 diet, there was a significant difference (p ≤ 0.05) in the AID values for amino acids and energy compared to those that consumed the P0 diet. Furthermore, the P250 diet significantly increased (p ≤ 0.05) the average daily weight gain compared to the P0 diet. No significant differences were observed between treatments in average daily feed intake and feed conversion ratio. In summary, the inclusion of 250 mg of encapsulated PTSO per kg in broiler chickens diet improved the digestibility of amino acids and energy, as well as weight gain.

Potential of cinnamaldehyde essential oil as a possible antimicrobial against fowl typhoid in layers

Fowl typhoid (FT) is an economically significant bacterial disease of layers leading to a drastic drop in egg production. Due to increased public health concerns about antibiotics in poultry feed, a search for new safe antimicrobials for treating fowl typhoid is crucial. The antimicrobial effect of cinnamaldehyde essential oil (CnEO) against fowl typhoid in layers was investigated in this experiment. The 60-week-old BV300-layer birds (n = 100) were divided into five groups: the non-challenged control group A, only cinnamaldehyde-treated group B (CnEO @ 1:8000 dilutions through drinking water for 60 days), the challenged group C, challenged plus cinnamaldehyde therapy group D (CnEO @ 1:8000 dilutions through drinking water from 16 to 30 dpi), and challenged plus antibiotic therapy group E (chloramphenicol @ 1 gm/5lit through drinking water from 16 to 30 dpi). Hens from all challenged groups were challenged with Salmonella Gallinarum (VTCCBAA588) @ 1 × 10⁸ CFU/ml orally. Various parameters such as clinical signs, mortality, egg production and egg weight, colony-forming unit (CFU) count of cecal content, eggshell surface, and egg yolk were evaluated all through 60 days of an experimental trial. Results indicated that, in the case of the cinnamaldehyde therapeutic group, there was a significant improvement in egg production, mild clinical signs, lower feed conversion ratio (FCR), and a significantly lower bacterial count in ceca and on the eggshell surface compared to the control challenge group. Thus, CnEO @ 1:8000 dilutions through drinking water can be a potential antimicrobial for controlling fowl typhoid.

Development of Novel Foxtail Millet-Based Nutri-Rich Instant Noodles: Chemical and Quality Characteristics

Noodles are a popular snack mainly produced from wheat flour; however, the low contents of protein, minerals, and lysine are a concern. Therefore, this research developed nutri-rich instant noodles by using foxtail millet (FTM) (Setaria italic) flour to improve the contents of protein and nutrients and increase its commercial importance. FTM flour was mixed with wheat flour (Triticum aestivum) at a ratio of 0:100, 30:60, 40:50, and 50:40, and the samples were named as control, FTM30, FTM40, and FTM50 noodles, respectively. Mushroom (Pleurotus ostreatus) and rice bran (Oryza sativa L.) flour were added at a percentage of 5% to all the composite noodles (FTM30, FTM40, and FTM50 noodles). The contents of biochemicals, minerals, and amino acids, as well as the organoleptic properties of the noodles, were examined and compared with wheat flour as a control. The results revealed that the carbohydrate (CHO) content of FTM50 noodles was significantly lower (p < 0.05) than all the developed and five commercial noodles named A-1, A-2, A-3, A-4, and A-5. Moreover, the FTM noodles had significantly higher levels of protein, fiber, ash, calcium, and phosphorous than the control and commercial noodles. The percentage of lysine calculated protein efficiency ratio (PER), essential amino acid index (EAAI), biological value (BV), and chemical score (CS) of FTM50 noodles were also higher than that of the commercial noodles. The total bacterial count was nil for the FTM50 noodles, and the organoleptic properties were consistent with those of acceptable standards. The results could encourage the application of FTM flours for the development of variety and value-added noodles with enhanced level of nutrients.

Effect of Vernonia amygdalina leaf meal on growth performance, intestinal mucosa activity, digestive enzymes, absorption capacity, and immunity in broiler chickens

Gut health is multifaceted and is largely influenced by the rearing environment and the diet. The use of phytochemicals rich in phenolics and flavonoids can improve the digestive health of chickens and lead to better growth performance. The aim of this study was to examine the effects of dietary Vernonia amygdalina leaf meal (VALM) on growth performance, digestive enzyme activities, absorption function, organ weights and immunity of broilers. Two hundred and forty, one-day-old male Cobb 500 broiler chicks were randomly divided into four groups: an unsupplemented control and VA-1, VA-3 and VA-5 receiving VALM incorporation at concentrations of 1, 3 and 5 g/kg, respectively. Each treatment had six replicates of 10 chickens. On d 42, six chickens per replicate were isolated and euthanised. Digesta from the jejunal segments (10 cm) was collected for analysis of the digestive enzymes. The remaining digesta was then washed out with ice-cold phosphate-buffered saline before the jejunal segments (10 cm) were opened longitudinally to collect the mucosa by scraping. For the preparation of the homogenate, intestinal mucosa samples were homogenised with 154 mmol/l of ice-cold sodium chloride solution and centrifuged at 4 °C for 900 s. To determine immunoglobulins, glutathione and D-xylose, the supernatant was extracted and stored at -20 °C. Supplementation with VALM did not significantly influence the relative weights of organs in the different treatments. However, VALM at 3 g/kg caused a significant increase in amylase and trypsin concentration (P<0.05). Immunoglobulin A and intestinal secretory immunoglobulin G concentrations were significantly improved (P<0.05) in the birds fed 3 g/kg VALM. This supported the premise that 3 g/kg VALM in feed can improve gastric immunity status and digestive enzyme secretion.

Effects of Supplemented Resveratrol on In Vitro Ruminal Fermentation and Growth Performance of Hanwoo Calves

We investigated the effects of resveratrol supplementation on in vitro ruminal fermentation and growth performance of Hanwoo calves. Treatment with three resveratrol concentrations (0%, 0.1%, 0.3%, and 0.5%) was used for in vitro ruminal fermentation. Resveratrol concentrations and pH of rumen fluid were negatively correlated (p < 0.05); therefore, total gas production, total volatile fatty acids, and acetate, propionate, and butyrate levels were significantly higher in the treatments than in the control at all time periods (p < 0.05). The appropriate resveratrol concentration that could be added without negative effects on the rumen was 0.3%. In farm experiments, we divided 14 Korean cattle calves into control (C) and 0.3% resveratrol (T) groups. There were no significant differences in the daily weight gain, feed conversion, final body weight, body length, withers height, and height at hip cross in the resveratrol-fed Hanwoo calves. Immunoglobulin G level was significantly higher in the treatment than in the control (p < 0.05), but IgA and IgM levels did not differ. Supplemental feeding of resveratrol is beneficial to in vitro ruminal fermentation, but it is important to supplement it at 0.3%. Furthermore, resveratrol affects calf immunoglobulin G.

Use of Cinnamon and its Derivatives in Poultry Nutrition

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

Bioactive compounds, antibiotics and heavy metals: effects on the intestinal structure and microbiome of monogastric animals – a non-systematic review

The intestinal structure and gut microbiota are essential for the animals‘ health. Chemical components taken with food provide the right environment for a specific microbiome which, together with its metabolites and the products of digestion, create an environment, which in turn is affects the population size of specific bacteria. Disturbances in the composition of the gut microbiota can be a reason for the malformation of guts, which has a decisive impact on the animal‘ health. This review aimed to analyse scientific literature, published over the past 20 years, concerning the effect of nutritional factors on gut health, determined by the intestinal structure and microbiota of monogastric animals. Several topics have been investigated: bioactive compounds (probiotics, prebiotics, organic acids, and herbal active substances), antibiotics and heavy metals (essentaial minerals and toxic heavy metals).

Growth performance, carcass yield and characteristics, meat quality, serum biochemistry, jejunal histomorphometry, oxidative stability of liver and breast muscle, and immune response of broiler chickens fed natural antioxidant alone or in combination with &lt;i&gt;Bacillus licheniformis&lt;/i&gt;

Abstract. In this study, oxidative stability of liver and breast meat, and immune response were evaluated in broiler chickens fed supplemental phytogenic feed additive (PFA) alone or in combination with Bacillus licheniformis. Three experimental groups – control, PFA (60 mg kg−1), and PFA (60 mg kg−1) + 0.5 mg kg−1 B. licheniformis (1.6 × 1012 cfu g−1), each consisting of 5 replicates – were established with 20 one-day-old chickens per replicate (300 birds in total). Growth performance, carcass yield and characteristics, and meat quality remained unaffected. However, supplemental PFA and PFA + B. licheniformis improved the serum biochemistry and jejunal histomorphometry of broiler chickens (P<0.05). PFA and PFA + B. licheniformis groups had lower thiobarbituric acid reacting substances (TBARS) in liver, and freeze–thaw breast meat after 30, 60, and 90 d of storage (P<0.05). PFA and PFA + B. licheniformis supplementation lowered the carbonyl group in fresh and stored breast meat (P<0.05). Antibody titer against infectious bursal disease virus was higher in the PFA + B. licheniformis group than the control group (P<0.05). It can be concluded that PFA or PFA + B. licheniformis in broiler diets improves the health, oxidative stability of liver and breast meat, and immune response of broiler chickens.

Metatranscriptomic Analysis of the Chicken Gut Resistome Response to In-Feed Antibiotics and Natural Feed Additives

The emergence of resistance against common antibiotics in the gut microbiota is a major issue for both human and livestock health. This highlights the need for understanding the impact of such application on the reservoir of antibiotic resistance genes in poultry gut and devising means to circumvent the potential resistome expansion. Phytogenic feed additives (PFAs) are potential natural alternative to antibiotic to improve animal health and performance, supposedly via positively affecting the gut microbial ecosystem, but there is little systematic information available. In this time-course study, we applied a shotgun meta-transcriptomics approach to investigate the impact of a PFA product as well as the commonly used antibiotic, zinc bacitracin either at AGP concentration or therapeutic concentration on the gut microbiome and resistome of broiler chickens raised for 35 days. Over the course of the trial, PFA treatments increased the abundance of Firmicutes such as Lactobacillus and resulted in a lower abundance of Escherichia, while the latter group increased significantly in the feces of chickens that received either AGP or AB doses of bacitracin. Tetracycline resistance and aminoglycoside resistance were the predominant antibiotic resistance gene (ARG) classes found, regardless of the treatment. PFA application resulted in a decrease in abundance of ARGs compared to those in the control group and other antibiotic treatment groups. In summary, the findings from this study demonstrate the potential of phytogenic feed additives could be an alternative to antibiotics in poultry farming, with the added benefit of counteracting antimicrobial resistance development.

Nature-identical compounds as feed additives in aquaculture

Aquaculture sustainable development is necessary since it is categorized as the most important source of aquatic products for human consumption and it is expected to keep growing shortly. For this reason, the addition of natural immunostimulants to fish diet to improve fish health and to preserve the environment have great importance in aquaculture. In this sense, new biotechnological tools as nature-identical compounds are now being used as feed additives to strengthen and stimulate the fish immune system to prevent and/or control diseases due to their lesser cost and higher availability than plant compounds. This review aims to present the most recent studies in which nature-identical compounds have been used in the fish diet to establish their possible use in aquaculture. Nature-identical compounds can be considered a promising alternative to be added to fish diets to promote growth performance, manipulate the gut microbiota, and improve the immune and oxidative status of fish as wells as control bacterial infections in this important aquatic industry.

The control of poultry salmonellosis using organic agents: an updated overview

Salmonellosis is a severe problem that threatens the poultry sector worldwide right now. Salmonella gallinarium and Salmonella pullorum (Fowl typhoid) are the most pathogenic serovars in avian species leading to systemic infection resulting in severe economic losses in the poultry industry. Nontyphoidal serotypes of Salmonella (Paratyphoid disease) constitute a public health hazard for their involvement in food poisoning problems in addition to their zoonotic importance. Also, Salmonella species distribution is particularly extensive. They resisted environmental conditions that made it difficult to control their spread for a long time. Therefore, the current review aimed to through light on Salmonellosis in poultry with particular references to its pathogenesis, economic importance, immune response to Salmonella, Salmonella antibiotics resistance, possible methods for prevention and control of such problems using promising antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, cinnamaldehyde, chitosan, nanoparticles, and vaccines.

Potential of a mixture of eugenol and garlic tincture to improve performance and intestinal health in broilers under necrotic enteritis challenge

Plant extracts (PE) are gaining increased attention as potential alternatives to in-feed antimicrobials (AM) due to their known antimicrobial activities. This study was conducted to examine the potential of PE, a microencapsulated product composed of eugenol and garlic tincture as an alternative to AM-agent on performance and intestinal health in broilers under necrotic enteritis (NE) challenge. A total of 960 day-old mixed-sex Cobb 500 chicks were randomly distributed to 48-floor pens with 6 treatments replicated 8 times with 20 birds each. The 6 treatments were as follows: UC, unchallenged control; CC, challenged control; PE, challenged group plus PE; AM, challenged group plus AM; FAP, challenged group plus a full dose of AM with PE; HAP, challenged group plus a half dose of AM with PE in starter, grower and finisher phases. Birds in the challenged groups were inoculated with Eimeria spp. on d 9 and Clostridium perfringens on d 14. The body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), and livability of birds were compromised, and intestinal lesions and mortality were increased (P < 0.05) by NE challenge, illustrating a successful clinical NE challenge. Birds fed AM had higher BWG and FI, and lower FCR, mortality, and intestinal lesions compared to the CC group (P < 0.05). Birds fed PE had improved FCR (P < 0.05) and livability (5.8%) in an overall period compared to the CC group. On d 16, PE supplementation reduced ileal lesion scores in only male birds (P < 0.05). Birds fed PE had decreased Eimeria maxima and Eimeria acervulina oocyst counts in caecal content (P < 0.05). Birds fed PE had decreased Escherichia brunetti and total oocyst counts in caecal content, and E. acervulina oocyst counts in ileal content in only female birds (P < 0.05). On d 35, PE supplementation reduced variation of BW in both male and female birds and increased yellowness (b∗ value, 14.4%) in the thigh. These findings suggest the potential of PE supplementation in diets to improve the performance and intestinal health of birds under clinical NE as indicated by improved FCR, livability, uniformity, reduced ileal lesions, oocyst counts and increased skin yellowness. However, the protective effect of PE may not be apparent in the presence of AM in the feed.

Effects of Capsaicin on Growth Performance, Meat Quality, Digestive Enzyme Activities, Intestinal Morphology, and Organ Indexes of Broilers

This experiment was conducted to investigate the effects of capsaicin (CAP) on growth performance, meat quality, digestive enzyme activities, intestinal morphology, and organ indexes of broilers. A total of 256 one-day-old Arbor Acre male broilers were randomly allocated into four treatments with eight replicates of eight birds, feeding a basal diet (control group), a basal diet supplemented with 2, 4, and 6 mg/kg CAP for 42 d, respectively. The growth performance, digestive enzyme activities of intestinal contents, small intestinal morphology, and organ indexes were measured at 21 and 42 d. The meat quality traits of breast muscles were determined at 42 d. The results showed dietary 4 mg/kg CAP supplementation decreased (P &lt; 0.05) the feed to gain ratio (F/G) in the grower phase (22–42 d) and overall (1–42 d) compared with the control group, and 2 mg/kg CAP group also decreased (P &lt; 0.05) the F/G from 1 to 42 d. Dietary 4 mg/kg CAP supplementation decreased (P &lt; 0.05) the drip loss at 48 h and the pH24h of breast muscles relative to the control group. Some digestive enzymes activities of jejunal and ileal contents were increased in the 2 and 4 mg/kg CAP groups compared with the control group both at 21 and 42 d. In addition, dietary 2 mg/kg CAP supplementation increased (P &lt; 0.05) the relative weight of liver, jejunal villus height, villus width, and villous surface area at 21 d; The length of the jejunum segment and the relative weight of Bursa of Fabricius at 42 d in the 4 mg/kg CAP group were higher (P &lt; 0.05) than the control group. In conclusion, dietary 2 or 4 mg/kg CAP supplementation decreased the F/G, improved meat quality, enhanced digestive enzyme activities, improved the jejunal development, and increased the relative liver and Bursa of Fabricius weight in broilers.

Probiotics, Prebiotics, and Phytogenic Substances for Optimizing Gut Health in Poultry

The gut microbiota has been designated as a hidden metabolic ‘organ’ because of its enormous impact on host metabolism, physiology, nutrition, and immune function. The connection between the intestinal microbiota and their respective host animals is dynamic and, in general, mutually beneficial. This complicated interaction is seen as a determinant of health and disease; thus, intestinal dysbiosis is linked with several metabolic diseases. Therefore, tractable strategies targeting the regulation of intestinal microbiota can control several diseases that are closely related to inflammatory and metabolic disorders. As a result, animal health and performance are improved. One of these strategies is related to dietary supplementation with prebiotics, probiotics, and phytogenic substances. These supplements exert their effects indirectly through manipulation of gut microbiota quality and improvement in intestinal epithelial barrier. Several phytogenic substances, such as berberine, resveratrol, curcumin, carvacrol, thymol, isoflavones and hydrolyzed fibers, have been identified as potential supplements that may also act as welcome means to reduce the usage of antibiotics in feedstock, including poultry farming, through manipulation of the gut microbiome. In addition, these compounds may improve the integrity of tight junctions by controlling tight junction-related proteins and inflammatory signaling pathways in the host animals. In this review, we discuss the role of probiotics, prebiotics, and phytogenic substances in optimizing gut function in poultry.

Effect of Dietary Rosemary and Ginger Essential Oils on the Growth Performance, Feed Utilization, Meat Nutritive Value, Blood Biochemicals, and Redox Status of Growing NZW Rabbits

Simple Summary

The rabbit farming industry has gained more interest due to its high productivity, high growth rate, and high-quality meat. One of the public health concerns is that global rabbit production is expected to increase to meet the increasing demand for lean meat. In the present study, we focused on the use of phytogenic feed additives (essential oils of rosemary (REO) and ginger (GEO)) as environmentally friendly supplementation to improve rabbit growth performance, physiological status, and meat quality. The results indicated that the use of REO and GEO at a dose of 0.5% dramatically improved the growth performance and feed utilization of treated rabbits. The cholesterol level decreased significantly in rabbit plasma and meat after REO and GEO treatments. The fat content tended to decline in the muscles and the triglycerides were remarkedly reduced in the plasma of treated animals. In addition, the oxidant/antioxidant balance in the plasma could be improved with supplementation with a high dose of REO and GEO. Accordingly, the use of REO and GEO as supplementations for growing rabbits could contribute to improving the sustainable production of the rabbit industry.

Abstract

This study was conducted to assess the impacts of using two essential oils, rosemary and ginger, on growing rabbits’ performance, carcass traits, meat composition, blood biochemicals, and the redox status of growing New Zealand White (NZW) rabbits. A total of 120 unsexed NZW rabbits, 42-days-old, were assigned randomly to five experimental groups (n = 24, 6 replicates with 4 rabbits each). The first group received a basal diet (control), the second to fifth groups were dietary supplemented daily with rosemary essential oil (REO) and ginger essential oil (GEO) at doses of 0.25 and 0.5% for each supplementation (REO-0.25, REO-0.5, GEO-0.25, and GEO-0.5), respectively. The growth traits were studied for 7 weeks, from the 7th to the 13th week of the rabbits’ age. The results revealed that final body weight, weight gain, and average daily gain increased significantly (p < 0.01) in the REO-0.5 and GEO-0.5 treatments compared to the control group. Daily feed intake decreased (p = 0.005) in essential oil treatments. Meanwhile, the feed conversion ratio improved significantly (p = 0.001) in REO and GEO at the high doses compared to the control group. The weight percentages of liver and giblets increased (p < 0.001) with both treatments of REO and GEO compared to the control group. The dietary supplementation with REO and GEO did not affect (p > 0.05) the meat composition of Longissimus dorsi and hind leg muscles. Meanwhile, REO and GEO supplementation significantly decreased cholesterol levels in the rabbit meat. Thiobarbituric acid reactive substance concentrations decreased by 10 and 15% in the meat of REO-0.5 and GEO-0.5 treatments, respectively, compared to the other groups. In the same trend, REO and GEO treatments induced a significant (p = 0.001) reduction in the plasma cholesterol concentrations and triglycerides compared to the control. The total antioxidant capacity increased by 7.60% and the malondialdehyde decreased by 11.64% in the plasma of GEO-0.5 treatment than the control. Thus, the dietary supplementation of REO and GEO have a beneficial effect in improving the productivity and meat quality of growing rabbits.

Essential oils and their nanoemulsions as green alternatives to antibiotics in poultry nutrition: a comprehensive review

Increasing market pressure to reduce the use of antibiotics and the Veterinary Feed Directive of 2019 have led to expanded research on alternate antibiotic solutions. This review aimed to assess the benefits of using essential oils (EOs) and their nanoemulsions (NEs) as feed supplements for poultry and their potential use as antibiotic alternatives in organic poultry production. Antibiotics are commonly used to enhance the growth and prevent diseases in poultry animals due to their antimicrobial activities. EOs are a complex mixture of volatile compounds derived from plants and manufactured via various fermentation, extraction, and steam distillation methods. EOs are categorized into 2 groups of compounds: terpenes and phenylpropenes. Differences among various EOs depend on the source plant type, physical and chemical soil conditions, harvest time, plant maturity, drying technology used, storage conditions, and extraction time. EOs can be used for therapeutic purposes in various situations in broiler production as they possess antibacterial, antifungal, antiparasitic, and antiviral activities. Several studies have been conducted using various combinations of EOs or crude extracts of their bioactive compounds to investigate their complexity and applications in organic poultry production. NEs are carrier systems that can be used to overcome the volatile nature of EOs, which is a major factor limiting their application. NEs are being progressively used to improve the bioavailability of the volatile lipophilic components of EOs. This review discusses the use of these nonantibiotic alternatives as antibiotics for poultry feed in organic poultry production.

Black Pepper or Radish Seed Oils in a New Combination of Essential Oils Modulated Broiler Chickens’ Performance and Expression of Digestive Enzymes, Lipogenesis, Immunity, and Autophagy-Related Genes

Optimal combinations of essential oils (EOs) can enhance performance and maintain poultry productivity. The effects of EOs with black pepper oil (BPO) or radish seed oil (RSO) on performance and the expression of digestive enzymes, lipogenesis, immunity, and autophagy-related genes in broiler chickens were explored. Six dietary treatments for 300 one-day-old chicks were allocated as follows: controls were fed a basal diet, one group was fed an EO-supplemented diet (1.5 g/kg diet of parsley, mint, and carrot seed oils (1:1:1)), and other groups received Eos + BPO0.25, Eos + BPO0.5, Eos + RSO0.25, and Eos + RSO0.5 treatments, with a basal diet containing EOs plus BPO or RSO at the level of 0.25 or 0.5 g/kg, respectively. Supplementation with 0.5 g/kg of EOs plus BPO or RSO resulted in the most improved maximum BWG and FCR in broiler chickens. The lactobacilli population was increased in Eos + BPO0.5, followed by EOs + RSO0.5, unlike in the control. The highest expression of the CCK and PNLIP genes was identified in the Eos + BPO group. The FAS and ACC genes were upregulated, while the IgA and IL-10 genes were downregulated, with EOs plus RSO or BPO. The group that received Eos + BPO0.5, followed by Eos + RSO0.5, displayed patterns of higher expression for atg5, atg7, and atg12, with lower expression of mTOR. In summary, a new combination of EOs with 0.5 g/kg BPO had potential growth-promoting and immune-boosting effects in broiler chickens.

Alternatives to antibiotics for organic poultry production: types, modes of action and impacts on bird's health and production

The poultry industry contributes significantly to bridging the nutritional gap in many countries because of its meat and eggs products rich in protein and valuable nutrients at a cost less than other animal meat sources. The natural antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, enzymes, immunostimulants, and phytogenic (phytobiotic) including herbs, botanicals, essential oils, and oleoresins are the most common feed additives that acquire popularity in poultry industry following the ban of antibiotic growth promoters (AGPs). They are commonly used worldwide because of their unique properties and positive impact on poultry production. They can be easily mixed with other feed ingredients, have no tissue residues, improve feed intake, feed gain, feed conversion rate, improve bird immunity, improve digestion, increase nutrients availability as well as absorbability, have antimicrobial effects, do not affect carcass characters, decrease the usage of antibiotics, acts as antioxidants, anti-inflammatory, compete for stress factors and provide healthy organic products for human consumption. Therefore, the current review focuses on a comprehensive description of different natural antibiotic growth promoters’ alternatives, the mode of their action, and their impacts on poultry production.

Combinatorial Effect of Dietary Oregano Extracts and 3,4,5-Trihydroxy Benzoic Acid on Growth Performance and Elimination of Coccidiosis in Broiler Chickens

We aimed to compare the combinatorial effect of 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (OE) with THB alone on the growth performance and elimination of deleterious effects in coccidiosis-infected broilers. A total of 210 one-day-old broilers were randomly assigned to one of five dietary treatments, with six replicates each, for 35 days. Dietary treatments were: 1) non-challenged, non-treated (NC); 2) challenged, non-treated (PC); 3) PC+ Salinomycin (0.05 g/kg; AB); 4) PC+THB (0.1 g/kg; THB); and 5) PC+THB+OE (0.1 g/kg; COM). On day 14, all groups except for NC were challenged with a 10-fold dose of Livacox^® T anticoccidial vaccine to induce mild coccidiosis. All treatments significantly improved (P<0.05) body weight, average daily gain, and average daily feed intake, compared to PC, on days 21, 28, and 35. However, all treatments significantly reduced (P<0.05) the feed conversion ratio of PC by more than 14.60% on day 35, 11.76% during growing period, and 10.36% through the entire period. Broilers receiving anticoccidial treatments had 54.23% and 51.86% lower lesion scores (P<0.05) at 4 and 7 days post-infection, respectively, compared to PC. Additionally, the villus height of COM was significantly longer (P < 0.05) than that of THB. Although the molecular action of COM remains unclear, OE addition to THB reduced the shedding of oocysts better than THB alone (P<0.05, 9-11 days post-infection). Most importantly, COM effectively minimized the mortality of challenged birds from as high as 11.90% (PC) to 0%, a level similar to NC and AB, while THB maintained a mortality of 2.38%. In conclusion, the anticoccidial effect of THB can be enhanced by the addition of OE for better animal performance and the elimination of deleterious effects from coccidiosis-infected broilers for 35 days.

Study on the Combined Toxicities and Quantitative Characterization of Toxicity Sensitivities of Three Flavor Chemicals and Their Mixtures to Caenorhabditis elegans

It was shown that flavor chemicals with high toxicity sensitivities mean that small changes in their effective concentrations can lead to significant changes in toxicity. Flavors are widely used in personal care products. However, our study demonstrated that some flavor chemicals and their mixture rays have high toxicity sensitivities to Caenorhabditis elegans (C. elegans), which may have an impact on human health. In this paper, three flavor chemicals (benzyl alcohol, phenethyl alcohol, and cinnamaldehyde) were used as components of the mixture, and three binary mixture systems were constructed, respectively. Five mixture rays were designed for each mixture system by a direct equipartition ray design method. The lethal toxicities of the three flavor chemicals and mixture rays to C. elegans at three exposure volumes were determined. A new concept (inverse of the negative logarithmic concentration span (iSPAN)) was introduced to quantitatively evaluate the toxicity sensitivity of chemicals or mixture rays, and the combination index (CI) was employed to identify the toxicological interactions in the mixtures. It was shown that the three flavor chemicals as well as the binary mixture rays have a significant concentration-response relationship on the lethality of C. elegans. The iSPAN values of the three flavor chemicals and their mixture rays were larger than 3.000, showing very strong toxicity sensitivity to C. elegans. In mixture systems, the toxicity sensitivities of mixture rays with different mixture ratios were also different at different exposure volumes. In addition, it can be seen from the CI heat map that the toxicological interaction not only shows the mixture ratio dependence but also changes with the different exposure volumes, which implies that the mixtures consisting of flavor chemicals with high toxicity sensitivity have complex toxicological interactions. Therefore, in environmental risk assessment, special attention should be paid to chemicals with high toxicity sensitivities.

Phytogenic Feed Additives in Poultry: Achievements, Prospective and Challenges

Simple Summary

Plant secondary metabolites and essential oils also known as phytogenics are biologically active compounds that have recently attracted increased interest as feed additives in poultry production, due to their ability to promote feed efficiency by enhancing the production of digestive secretions and nutrient absorption, reduce pathogenic load in the gut, exert antioxidant properties and decrease the microbial burden on the animal’s immune status. However, the mechanisms are far from being fully elucidated. Better understanding the interaction of phytogenics with gastrointestinal function and health as well as other feed ingredients/additives is crucial to design potentially cost-effective blends.

Abstract

Phytogenic feed additives have been largely tested in poultry production with the aim to identify their effects on the gastrointestinal function and health, and their implications on the birds’ systemic health and welfare, the production efficiency of flocks, food safety, and environmental impact. These feed additives originating from plants, and consisting of herbs, spices, fruit, and other plant parts, include many different bioactive ingredients. Reviewing published documents about the supplementation of phytogenic feed additives reveals contradictory results regarding their effectiveness in poultry production. This indicates that more effort is still needed to determine the appropriate inclusion levels and fully elucidate their mode of actions. In this frame, this review aimed to sum up the current trends in the use of phytogenic feed additives in poultry with a special focus on their interaction with gut ecosystem, gut function, in vivo oxidative status and immune system as well as other feed additives, especially organic acids.

Effects of red-osier dogwood extracts on growth performance, intestinal digestive and absorptive functions, and meat quality of broiler chickens

A total of 320 one-day-old Cobb 500 chicks with an initial weight of 48.3 ± 3.3 g·pen−1 were assigned to four dietary treatments with eight replicates provided in three phases for 46 d. The treatments were fed as mash diets and included (1) negative control (NC) corn-soybean basal diet, (2) positive control (PC) basal diet with 30 ppm avilamycin, (3) basal diet supplemented with 1000 ppm red-osier dogwood extracts (RDE1), and (4) basal diet with 3000 ppm red-osier dogwood extracts (RDE2). Results showed reduced jejunal crypt depth in RDE1 and increased villus:crypt ratio in groups (either RDE1 or RDE2) (P < 0.05). Cationic amino acid (AA) transporter mRNA abundance was decreased (P < 0.05) in RDE1, RDE2, and PC treatments, but peptide and neutral AA transporter mRNA abundance were higher (P < 0.05) in RDE2 compared with NC. Apparent ileal digestibility of crude fat was increased in RDE2 and PC compared with NC, whereas AA digestibility was greater in RDE1, RDE2, and PC (P < 0.05). In conclusion, red-osier dogwood had no effect on growth performance, improved the intestinal health and function of broiler chickens, and had no detrimental effects on meat quality.

The effect of essential oils on cholesterol content in chicken meat

The study aimed to investigate cholesterol content in chicken breast and thigh muscles by the influence of feed supplements of various content of essential oils. The experiment was carried out under practical conditions in a poultry farm with broiler chickens of the Cobb 500 hybrid combination according to the feed supplement used thyme essential oil, cinnamon essential oil, commercial citrus fruit essential oil, and their combination. The control group was without the use of experimental feed supplements and commercial coccidiostats were used in their feed mixtures. The experiment lasted 40 days in welfare conditions. Broiler chickens were used for sample preparation of breast and thigh muscles with the skin and their analysis for dry matter, fat and cholesterol contents. Samples were analyzed using a Nicolet 6700 FT-IR Fourier transform infrared spectrometer. The results were processed by the SAS system program, version 8.2. The results, which were evaluated, indicated a tendency to reduce the cholesterol content in chicken breast muscle due to cinnamon essential oil and the combination of cinnamon essential oil with citrus fruit essential oil as well as thyme essential oil with citrus fruit essential. In the achieved results of dry matter, fat, and cholesterol content in breast and thigh muscles, the difference between the effects of the used feed supplements based on essential oils and concerning the control group were not statistically significant p >0.05. The correlation was a statistically significant strong linear relation only between dry matter content and fat content due to thyme and cinnamon essential oils. In conclusion, it was stated that the investigation of the feed supplement effect based on essential oils is an open question concerning the production of safe food of animal origin.

Cinnamon: A Natural Feed Additive for Poultry Health and Production-A Review

The increased bacterial resistance to synthetic antibiotics and consumer awareness about the health and food safety concerns have triggered the ban on the use of antibiotic growth promotors (AGPs) in the poultry industry. This situation encouraged the poultry sector and industry to explore safe alternatives to AGPs and focus on developing more sustainable feed management strategies to improve the intestinal health and growth performance of poultry. Consequently, phytogenic feed additives (PFAs) have emerged as natural alternatives to AGPs and have great potential in the poultry industry. In recent years, cinnamon (one of the most widely used spices) has attracted attention from researchers as a natural product with numerous health benefits for poultry. The essential oils in cinnamon, in particular, are of interest because of their antioxidant, anti-microbial, anti-inflammatory, antifungal, and hypocholesterolaemic effects, in addition to their ability to stimulate digestive enzymes in the gut. This review mainly emphasizes the potential impact of cinnamon as a natural feed additive on overall gut health, nutrient digestibility, blood biochemical profile, gene expression, gut microbiota and immune response.

The Applicability of Essential Oils in Different Stages of Production of Animal-Based Foods

Essential oils (EOs) have been used for centuries, and interest in these compounds has been revived in recent years. Due to their unique chemical composition as well as antimicrobial, immunostimulatory, anti-inflammatory and antioxidant properties, EOs are used in pharmacology, cosmetology and, increasingly, in animal breeding and rearing, and processing of animal raw materials. Essential oils have become a natural alternative to preservatives, taste enhancers and, most importantly, antibiotics, because the European Union banned the use of antibiotics in metaphylaxis in animal husbandry in 2006. In the animal production chain, EOs are used mainly as feed additives to improve feed palatability and increase feed intake, improve animal resistance and health status, and to prevent and treat diseases. Recent research indicates that EOs can also be applied to sanitize poultry houses, and they can be used as biopesticides in organic farming. Essential oils effectively preserve meat and milk and, consequently, improve the safety, hygiene and quality of animal-based foods. Novel technologies such as encapsulation may increase the bioavailability of EOs and their application in the production of food and feed additives.

Effects of natural capsicum extract on growth performance, nutrient utilization, antioxidant status, immune function, and meat quality in broilers

This research was conducted to determine the effects of natural capsaicin extract (NCE) as an alternative to the antibiotic (chlortetracycline, CTC) on growth performance, antioxidant capacity, immune function, and meat quality of broiler chickens. A total of 168 one-day-old Arbor Acre male broiler chickens with an average weight of 46.4 ± 0.6 g were randomly allotted to 3 dietary treatments, with 7 replicates per treatment and 8 broilers per pen. These 3 dietary treatments included a corn-soybean meal basal diet (CON), a basal diet + 75 mg/kg CTC (CTC), and a basal diet + 80 mg/kg NCE (NCE). Broilers from the NCE group showed higher average daily gain compared to broilers from the CON group at all stages (P < 0.05). On d 42, NCE supplementation improved dietary nitrogen-corrected apparent metabolizable energy compared to nonsupplemented or CTC-supplemented diets (P < 0.05). The digestibility of organic matter and crude protein were higher in the NCE diet than in the CON or CTC diets (P < 0.05). Higher relative weight of bursa of Fabricius was observed in broilers fed NCE diets compared with CON (P < 0.05). Pancreatic trypsin and lipase activities were significantly increased in the NCE group compared with those in the CON group (P < 0.05). The value of lightness (L*) of breast muscles from broilers fed NCE diets was significantly lower compared to those fed CON diets (P < 0.05). Broilers fed NCE diets also had higher levels of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and lower levels of interleukin-1β, and tumor necrosis factor-α compared with broilers fed CON diets (P < 0.05). The liver catalase activity of broilers was also significantly increased in the NCE group than the CON group (P < 0.05). In addition, broilers from NCE group had lower concentrations of serum urea-N, low-density lipoprotein cholesterol, and total cholesterol, and higher concentration of growth hormone compared with those from the CON group (P < 0.05). Therefore, we concluded that supplementation of 80 mg/kg of NCE in diets could improve growth performance, nutrient digestibility, antioxidant status, immune function, and meat quality in broilers.

Are There Effective Intervention Measures in Broiler Production against the ESBL/AmpC Producer Escherichia coli?

Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) producing Enterobacteriaceae occur frequently in livestock animals and the subsequent stages of the meat production chain and are therefore considered a risk for human health. Strict biosecurity measures and optimal farm management should reduce or even prevent poultry flock colonization at farm level. This review summarizes and evaluates published information on the effectiveness of specific intervention measures and farm management factors aiming to reduce the occurrence and spread of ESBL/AmpC producing or commensal or pathogenic E. coli in broiler chicken farms. In this systematic literature review, a total of 643 publications were analyzed, and 14 studies with significant outcome about the effectiveness of specific measures against E. coli and ESBL/AmpC producing E. coli in broiler chicken farms were found. Different feed additives seem to have an impact on the occurrence of those microorganisms. The measures ‘cleaning and disinfection’ and ‘competitive exclusion’ showed strong effects in prevention in some studies. In summary, some intervention measures showed potential to protect against or eliminate ESBL/AmpC-producing, commensal or pathogenic E. coli at farm level. Due to the high variability in the outcome of the studies, more specific, detailed investigations are needed to assess the potential of the individual intervention measures.

Effect of a Phytogenic Feed Additive on Growth Performance, Nutrient Digestion, and Immune Response in Broiler-Fed Diets with Two Different Levels of Crude Protein

Simple Summary

The rising concerns on antibiotics resistance from using antibiotics in animal production has resulted in an increase in researches on antibiotic alternatives. A phytogenic feed additive from a blend of extracts of oregano, cinnamon, citrus peel, and fructooligosaccharides was evaluated in the present study. The objective of the present study is not only to evaluate the effect of phytogenic feed additive on broiler performance, but also to explore the potential mode of actions through immune response, digestive enzyme activities, nutrient transporter gene expressions and nutrient digestibility. Supplementation of phytogenic feed additives improved broiler FCR through stimulating ileum immunity.

Abstract

The aim of this experiment was to evaluate the effect of a phytogenic feed additive (PFA) on growth performance and nutrient digestibility of broilers fed corn and soybean meal-based diets containing two different levels of crude protein. A 2 × 2 completely randomized factorial arrangement (eight replicates/treatment, 30 birds/replicate) was conducted with a positive control (PC) and negative control (NC) containing crude protein at standard or reduced by 1.5% (equivalent to a reduction of 15 g/kg), respectively, and supplementation of PFA at 0 or 125 ppm of diet. There were no significant interactions found between PFA and CP levels in the current study. Main effect analysis showed that during 0–42 d of age NC diets decreased body weight gain (p < 0.05), but increased feed intake (p < 0.05) and feed conversion ratio (FCR, p < 0.01), whereas supplementation of PFA resulted in a lower FCR (p < 0.01). The ileal nutrient digestibility was reduced (p < 0.05) in the broilers fed a reduced protein diet at 21 d compared to the standard protein level group, but there were no effects for PFA levels. Similarly, supplementing PFAs showed no effects on digestive enzyme (Alkaline phosphatase, amylase, and lipase) activity in jejunal digesta and jejunal brush border enzyme (maltase, sucrase, and aminopeptidase) activity. Supplementation of PFA downregulated (p < 0.05) the mRNA expressions of cytochrome P450 1A and interleukin 6 in the ileum but had no effects on nutrient transporter genes in the jejunum. In conclusion, supplementation of PFA reduced broiler FCR during the whole grow-out period and positively regulated the immune responses in the ileum.

Natural capsicum extract replacing chlortetracycline enhances performance via improving digestive enzyme activities, antioxidant capacity, anti-inflammatory function, and gut health in weaned pigs

The objective of this study was to investigate the effects of natural capsicum extract (NCE, containing 2% natural capsaicin, the rest is carrier) replacing chlortetracycline (CTC) on performance, digestive enzyme activities, antioxidant capacity, inflammatory cytokines, and gut health in weaned pigs. A total of 108 weaned pigs (Duroc × [Landrace × Yorkshire], initial body weight = 8.68 ± 1.34 kg; weaned on d 28) were randomly allotted into 3 treatments with 6 replicate pens per treatment (3 barrows and 3 gilts per pen). The treatments include a corn-soybean meal basal diet as a control group (CON), a CTC group (basal diet + CTC at 75 mg/kg), and a NCE group (basal diet + NEC at 80 mg/kg). Compared with CON and CTC, NCE had increased (P < 0.05) average daily gain in phase 2 (d 15 to 28) and overall (d 1 to 28), and higher (P < 0.05) apparent total tract digestibility of gross energy, dry matter, crude protein, and organic matter in phase 1 (d 1 to 14). These pigs also had increased (P < 0.05) pancrelipase activity in pancreas, α-amylase, lipase and protease activities in the jejunal mucosa, and lipase activity in the ileal mucosa on d 28. Moreover, NCE had increased (P < 0.05) the contents of growth hormone, β-endorphin, 5-hydroxytryptamine, total antioxidant capacity, total superoxide dismutase, catalase, and IL-10, as well as decreased (P < 0.05) contents of malondialdehyde, tumor nuclear factor-α, interferon-γ, and interleukin-6 in serum on d 28 compared with CON and CTC. NCE showed higher (P < 0.05) propionic acid, butyric acid and total volatile fatty acids (VFA) contents, and increased (P < 0.05) relative abundance of Faecalibacterium in colon, as well as higher (P < 0.05) propionic acid and total volatile fatty acids in cecum on d 28 compared with CON. In conclusion, NCE replacing CTC could enhance performance via improving digestive enzyme activities, antioxidant capacity, anti-inflammatory function, gut VFA composition and microbiota community in weaned pigs, and it could be used as a potential target for the development of feed additives.

Effect of fennel essential oil on performance, serum biochemistry, immunity, ileum morphology and microbial population, and meat quality of broiler chickens fed corn or wheat-based diet

1. The effect of Foeniculi aetheroleum essential oil (EO) on growth performance, nutrient utilisation, serum biochemistry, immune response, ileum morphology, microbial population and meat quality of broiler chickens fed a corn- or wheat-based diet were determined.2. A total of 360 broiler chickens were arranged in a 2 × 2 factorial assay in a completely randomised design with six replicates and 15 birds per experimental unit. Birds were fed corn- or wheat-based diets supplemented with (200 mg/kg) or without fennel EO.3. Birds fed wheat-based diets had lower BWG and FCR during grower period and lower FI during finisher period as compared to those fed corn-based diet (P < 0.05) whereas addition of fennel EO decreased chickens BWG during finisher period and EPEF, both in wheat or in corn-based diets. Dietary treatments had no effect on serum glucose, triglyceride, cholesterol, LDL-cholesterol, AST, ALT, ALP, and MDA concentrations (P < 0.05).4. Antibody titres against avian influenza and sheep red blood cell antibody titres, crude protein and crude fat utilisation, villus height, crypt depth and epithelium thickness were not influenced by dietary treatments (P > 0.05). Inclusion of Fennel EO to the corn-based diet resulted in greater villus width and villus surface area while it reduced lamina propria thickness (P < 0.05). Fennel EO reduced ileal E. coli and Lactobacillus spp. populations (P < 0.05). Dietary treatments had no significant effect on meat pH, cooking loss, drip loss, crude protein, crude fat content and cholesterol concentration of breast and thigh meat, total phenolic and MDA concentrations, and breast meat sensory parameters (P > 0.05).5. These results showed that addition of fennel EO to wheat-based diets had a negative effect on chicken growth performance variables and decreased gut E. coli populations. However, immunity, meat quality and nutrient utilisation were not affected by dietary treatments.

Effects of Essential Oils-Based Supplement and Salmonella Infection on Gene Expression, Blood Parameters, Cecal Microbiome, and Egg Production in Laying Hens

One of the main roles in poultry resistance to infections caused by Salmonella is attributed to host immunity and intestinal microbiota. We conducted an experiment that involved challenging Lohmann White laying hens with Salmonella Enteritidis (SE), feeding them a diet supplemented with an EOs-based phytobiotic Intebio^®. At 1 and 7 days post-inoculation, the expression profiles of eight genes related to immunity, transport of nutrients in the intestine, and metabolism were examined. Cecal microbiome composition and blood biochemical/immunological indices were also explored and egg production traits recorded. As a result, the SE challenge of laying hens and Intebio^® administration had either a suppressive or activating effect on the expression level of the studied genes (e.g., IL6 and BPIFB3), the latter echoing mammalian/human tissue-specific expression. There were also effects of the pathogen challenge and phytobiotic intake on the cecal microbiome profiles and blood biochemical/immunological parameters, including those reflecting the activity of the birds' immune systems (e.g., serum bactericidal activity, β-lysine content, and immunoglobulin levels). Significant differences between control and experimental subgroups in egg performance traits (i.e., egg weight/number/mass) were also found. The phytobiotic administration suggested a positive effect on the welfare and productivity of poultry.

Oregano essential oil improves piglet health and performance through maternal feeding and is associated with changes in the gut microbiota

Background

With a growing demand for safe and sustainable alternatives to antimicrobials, functional feed ingredients such as plant essential oils have been evaluated for their potential to improve gut health. Amongst these, oregano essential oil (OEO) with the main active compounds carvacrol and thymol has been reported to have antimicrobial and antioxidative properties resulting in improved intestinal barrier function and growth in pigs and poultry. However, its impact on the gut microbiota still remains unclear. The aim of this study was to examine the effect of an oregano essential oil phytobiotic on sow and piglet performance and faecal microbiota.

Results

Piglets from OEO supplemented sows were significantly heavier at one week of age and showed a trend for improved average daily weight gain from birth to weaning. Post-weaning, maternally supplemented piglets were numerically heavier at 10 weeks post-weaning and at slaughter with a reduced variability in bodyweight. Health records showed that piglets in the OEO supplemented litters had significantly reduced incidence of therapeutic treatment and reduced mortality. In both sows and piglets, the structure and composition of the faecal microbiota varied considerably over time. Sows supplemented with OEO during lactation showed an increase in the relative abundance of Lactobacillaceae family. In addition, there was an increase in the relative abundance of families known to be important in fibre digestion (Fibrobacteriaceae and Akkermansiaceae). Analysis of piglet microbiota at two weeks and four weeks of age revealed a relative decrease in Enterobacteriaceae while butyrate producers (Lachnospiraceae family) were increased at both timepoints.

Conclusion

We hypothesise that the effects observed from this study were exerted through modulation of the gut microbial communities in the sow and her offspring through maternal microbial transfer. Understanding the link between the gut microbiota and dietary factors represents a keystone to improving health and performance for sustainable pig production. Reducing antimicrobial usage can help to reduce the risk of antimicrobial resistance (AMR) which is a global focus for animal production.

Effect of Shirazi thyme on oxidant status and absorptive surface area of the intestine in cold-induced pulmonary hypertensive broiler chickens

The effects of Shirazi thyme as a medicinal plant on oxidant status (lipid peroxidation, protein oxidation, total antioxidant capacity, and catalase activity) and absorptive surface area were measured in three segments of the small intestine in cold-induced pulmonary hypertensive chickens. Birds were reared at four groups (thyme 0, 0.25, 0.50, and 1.00 % of diet) for 42 days. To induce pulmonary hypertension, the temperature was gradually decreased. The body weight was increased in thyme-0.25% birds compared to control ones, while it was decreased in thyme-1% of birds. The feed consumption was only increased in thyme-1.00% birds. The feed conversion ratio was lower in thyme-0.25% birds and higher in thyme-1.00% birds than control ones. The duodenal and jejunal villus surface area was lower in thyme-1.00% birds than control ones, while it was greater in the thyme-0.50% birds. The ileal villus surface area and duodenal lamina propria thickness were also greater in thyme-0.50% birds. Lipid peroxidation was only decreased in the duodenum and ileum of thyme-0.50% birds compared to control ones, whereas it was increased in the duodenum and jejunum of thyme-1.00% birds. Catalase activity was only elevated in the duodenum and jejunum of thyme-1.00% fed chickens. Total antioxidant capacity was increased in the duodenum, jejunum, and ileum of thyme-0.50% birds. It is concluded that the Shirazi thyme has beneficial effects on growth performance, intestinal absorptive surface area / secretory system, and pulmonary hypertension response at low doses (0.25 and 0.50% of diet), whereas high dose (1.00% of diet) of this plant may be toxic.

In vitro and in vivo activity of cinnamaldehyde against Eimeria kofoidi in chukar partridge (Alectoris chukar)

One hundred and twenty one-day-old chukar partridges were randomly divided into eight groups which received diets with different supplementations. There were four unchallenged groups. One group received salinomycin (50 ppm), two groups received cinnamaldehyde (CINN) (100 and 200 mg/kg of diet), and another one received only the basal diet from the 1st to the 31st day. There were also four corresponding groups orally challenged by 3 × 10⁵Eimeria kofoidi sporulated oocysts at the 21st day. Three samplings were done at the 24th, 26th, and 31st days of rearing for pathological and biochemical assessments. Fecal samples were daily taken to check the pattern of oocyst shedding from the 26th to 31st day. The body weight of birds was measured at 21st and 31st days. Along with the in vivo experiment, an in vitro sporulation inhibition test was carried out. The in vitro results showed that CINN decreased sporulation rate at 1 and 0.5 mg/ml. In vivo, it was found that CINN did not prevent the oocyst shedding. Furthermore, the histopathological findings revealed that CINN and salinomycin had no effect on infection establishment. However, our findings showed that CINN (200 mg/kg of diet) could enhance the body weight and improve antioxidant status. Although our results did not support the in vivo anticoccidial activity of CINN, it had a promising potential to improve antioxidant status and body weight in the chukar partridge.