Growth performance and endogenous losses of broilers fed wheat-based diets with and without essential oils and xylanase supplementation

Broiler chicken response to xylanase and fermentable xylooligosaccharide supplementation

A study was conducted to determine the effect of dietary fiber (DF), xylanase (XYL), xylooligosaccharides (XOS), and a combination of XYL and xylooligosaccharides (STBIO) on chicken growth performance, N-corrected apparent metabolizable energy (AMEn), and nutrient availability, characteristics of the gastrointestinal tract (GIT), and cecal content of short-chain fatty acids (SCFA). A 35-day experiment was performed on 1,920 as hatched Ross 308 broiler chicks, reared in 96 pens and fed ad libitum. Experimental diets were split into 2 phases: starter (0-21 d) and finisher (22-35 d). There were 2 basal diets, first contained 54% maize and in the second, 5% of the maize was replaced by wheat bran as DF. The diets were split into 4 batches: one of them was used as a control, and each of the others were supplemented either with XYL or XOS or with the STBIO. Each diet was fed to 12 pens following randomization. The data were analyzed in GenStat (20th edition) by ANOVA using a 2 × 4 factorial design. The addition of STBIO improved feed conversion ratio (FCR) and increased weight gain (WG) from 21 to 35 d and from 0 to 35 d (P < 0.05). The inclusion of DF had a negative effect on N and fat retention coefficients at 35 d as well as AMEn and dry matter retention at 21 and 35 d. At 21 d, neutral detergent fiber (NDF) retention was increased when xylanase and STBIO were added to the diet (P < 0.001) and at d 35 the highest retention was noted when the diet was supplemented with DF and XYL or STBIO (P = 0.001). There was no dietary effect on jejunum histomorphometry (P > 0.05). The addition of DF increased the concentration of cecal SCFA in particular valeric and propionic acid at 35-day-old birds (P < 0.05). It can be concluded that addition of STBIO in diet could provide benefits in terms of fiber degradation, WG, and feed efficiency.

Dietary coated essential oil and organic acid mixture supplementation improves health of broilers infected with avian pathogenic Escherichia coli

Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is a very prevalent disease in poultry farms in China. The exploration of effective non-antibiotic substances is of great significance for the control of APEC infections. This experiment evaluated the efficacy of coated essential oil and organic acid (EOA) supplementation to prevent E. coli O78 infection in broiler chickens. A total of 288 one-day-old male broiler chicks were randomly distributed into 4 groups with 6 replicates per group. Chickens were fed a diet either supplemented with EOA (500 mg/kg feed) or not, and either uninfected or infected with E. coli O78 intratracheally. Results showed that E. coli O78 infection reduced body weight gain, increased mortality and the ratio of feed to gain along with cecal and liver E. coli load, damaged gut mucosa, induced local and systemic inflammation, and altered cecal microbial composition, diversity and function (P < 0.05). Supplemental EOA improved feed conversion efficiency, lowered gross lesion scores and cecal E. coli population, enhanced intestinal goblet cells and serum IgG concentration, and tended to decrease serum IL-12 production (P < 0.05). Essential oil and organic acid addition downregulated IFN-γ mRNA, tended to decrease mucin-2 mRNA levels while upregulating IL-10 mRNA, and tended to increase ZO-1 gene expression in the jejuna of infected birds at 7 d after E. coli O78 challenge (P < 0.05). The 16S rRNA gene sequencing indicated that both EOA addition and E. coli O78 challenge altered the diversity and composition of the cecal microbiota community. Furthermore, infected birds fed EOA showed decreased Bacteroidetes and genus Lactobacillus abundance compared with the infected control. LEfSe analysis showed that Firmicutes, Ruminococcaceae, Clostridiales, Clostridia, Lactobacillus, Lactobacilaceae, and cc-115 were enriched in the non-infected but EOA-treated group (P < 0.05). Collectively, dietary EOA supplementation could mildly alleviate E. coli-induced gut injury and inflammation.

Rapeseed meal processing and dietary enzymes modulate excreta inositol phosphate profile, nutrient availability and production performance of broiler chickens

This study aimed to assess the effect of rapeseed meal (RSM) processing method, where solvent extraction occurred under standard industry conditions (ST) or cold-pressed hexane extraction was employed (MT), and exogenous enzyme supplementation (phytase [PHY] and xylanase [XYL]) alone or in combination on key nutritional factors of broiler chickens. A randomized control experiment was performed using 144 male Ross 308 broilers in a 2 × 2 × 3 factorial arrangement. Three diets including a nutritionally complete wheat-based basal diet (BD), a diet containing 200 g/kg of RSM extracted under ST and another diet containing 200 g/kg of RSM extracted under MT were produced. Each diet was then split into 4 parts and was fed as is, or supplemented with PHY at 1,500 FTU/kg or XYL at 16,000 BXU/kg, alone or in combination, resulting in 12 diets in total. Response criteria: feed intake (FI), weight gain (WG), and feed conversion ratio (FCR), from 7 to 21 d age, AMEn, retention coefficients for dry matter (DMR), nitrogen (NR), fat (FR), and the profile of inositol phosphate esters (IP2-6) and myo-inositol (MI) in excreta. Diets containing MT had higher AMEn compared to ST diets (P < 0.05). There was RSM by PHY interaction for FI, as only birds fed MT diet responded to PHY supplementation with reduced FI and FCR (P < 0.001). Feeding XYL reduced overall FI and FCR (P < 0.05). Feeding PHY reduced IP6 and increased MI in excreta (P < 0.001). Feeding XYL and PHY in combination reduced MI in excreta compared to PHY only (P = 0.05). Compared to BD, birds fed RSM diets had an increased IP6 (P < 0.05) and MI concentration in excreta (P < 0.01). This may be due to IP ester differences in RSM and BD.

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.

Allium-Based Phytobiotic for Laying Hens' Supplementation: Effects on Productivity, Egg Quality, and Fecal Microbiota

The poultry industry is constantly demanding novel strategies to improve the productivity and health status of hens, prioritizing those based on the holistic use of natural resources. This study aimed to assess the effects of an Allium-based phytobiotic on productivity, egg quality, and fecal microbiota of laying hens. One hundred and ninety-two 14-week-old Lohmann Lite LSL hens were allocated into an experimental farm, fed with a commercial concentrate with and without the Allium-based phytobiotic, and challenged against Salmonella. Productivity, egg quality, and fecal microbiota were monitored for 20 weeks. Results showed that the phytobiotic caused an increase on the number of eggs laid (p < 0.05) and in the feed conversion rate (p < 0.05); meanwhile, egg quality, expressed as egg weight, albumin height, haugh units, egg shell strength, and egg shell thickness remained unchanged (p > 0.05), although yolk color was decreased. Fecal microbiota structure was also modified, indicating a modulation of the gut microbiota by increasing the presence of Firmicutes and Bacteroidetes but reducing Proteobacteria and Actinobacteria phyla. Predicted changes in the functional profiles of fecal microbiota suggest alterations in metabolic activities that could be responsible for the improvement and maintenance of productivity and egg quality when the phytobiotic was supplemented; thus, Allium-based phytobiotic has a major impact on the performance of laying hens associated with a possible gut microbiota modulation.

Effect of blending encapsulated essential oils and organic acids as an antibiotic growth promoter alternative on growth performance and intestinal health in broilers with necrotic enteritis

The effects of a blend of encapsulated organic acids with essential oils (EOA) as an alternative to antimicrobial growth promoter (AGP) on growth performance and gut health of Eimeria spp./Clostridium perfringens (C. perfringens) in chickens infected with necrotic enteritis (NE) broilers was investigated. A total of 432 male Arbor Acres broilers (1-day-old) were randomly distributed into 6 treatment groups, namely noninfected negative control (A); NE-infected positive control (D); NE-infected broiler chickens fed a basal diet supplemented with 250 mg/kg bacitracin methylene disalicylate (BMD) plus 90 mg/kg monensin; and NE-infected broiler chicken fed 200; 500; and 800 mg/kg EOA (E, F, G, and H group). Feeding EOA at 200 and 500 mg/kg considerably improved the feed conversion ratio, reduced gut lesions, serum fluorescein isothiocyanate dextran level, and C. perfringens load in the caecum and liver of the NE-infected broiler chickens. This feed was similar to AGP. Furthermore, the increased villous height-to-crypt depth ratio and goblet cells counts, upregulated claudin-1, glucagon-like peptide-2 (GLP-2), insulin-like growth factor-2 (IGF-2) mRNA gene expression, downregulated occludin, zonula occludens-1 (ZO-1), toll-like receptor (TLR-4), interleukin (IL-1β), interferon γ (IFN-γ), TNF receptor-associated factor 6 (TRAF-6), tumor necrosis factor superfamily member 15 (TNFSF15), and Toll-interacting protein (Tollip) genes expression in the jejunum were observed in the NE-infected broiler chickens that received EOA at 200 and 500 mg/kg compared with those of the single NE-challenged groups without EOA supplementations (P < 0.05). The 16S analysis revealed that EOA supplemented with 200 or 500 mg/kg enriched relative abundance of Lactobacillus, unclassified_Lachnospiraceae, and Enterococcus, and carbohydrate metabolic pathways but suppressed unclassified_Erysipelotrichacease and organismal systems involved in the immune system (P < 0.05). Feeding EOA could alleviate NE-induced gut impairment and growth depression and modulate cecal microbiota composition, which has potential as antimicrobial alternatives.

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.

Development and Functional Properties of Intestinal Mucus Layer in Poultry

Intestinal mucus plays important roles in protecting the epithelial surfaces against pathogens, supporting the colonization with commensal bacteria, maintaining an appropriate environment for digestion, as well as facilitating nutrient transport from the lumen to the underlying epithelium. The mucus layer in the poultry gut is produced and preserved by mucin-secreting goblet cells that rapidly develop and mature after hatch as a response to external stimuli including environmental factors, intestinal microbiota as well as dietary factors. The ontogenetic development of goblet cells affects the mucin composition and secretion, causing an alteration in the physicochemical properties of the mucus layer. The intestinal mucus prevents the invasion of pathogens to the epithelium by its antibacterial properties (e.g. β-defensin, lysozyme, avidin and IgA) and creates a physical barrier with the ability to protect the epithelium from pathogens. Mucosal barrier is the first line of innate defense in the gastrointestinal tract. This barrier has a selective permeability that allows small particles and nutrients passing through. The structural components and functional properties of mucins have been reviewed extensively in humans and rodents, but it seems to be neglected in poultry. This review discusses the impact of age on development of goblet cells and their mucus production with relevance for the functional characteristics of mucus layer and its protective mechanism in the chicken’s intestine. Dietary factors directly and indirectly (through modification of the gut bacteria and their metabolic activities) affect goblet cell proliferation and differentiation and can be used to manipulate mucosal integrity and dynamic. However, the mode of action and mechanisms behind these effects need to be studied further. As mucins resist to digestion processes, the sloughed mucins can be utilized by bacteria in the lower part of the gut and are considered as endogenous loss of protein and energy to animal. Hydrothermal processing of poultry feed may reduce this loss by reduction in mucus shedding into the lumen. Given the significance of this loss and the lack of precise data, this matter needs to be carefully investigated in the future and the nutritional strategies reducing this loss have to be defined better.

Essential oils as growth-promoting additives on performance, nutrient digestibility, cecal microbes, and serum metabolites of broiler chickens: a meta-analysis

OBJECTIVE

The purpose of this meta-analysis was to evaluate the effect of dietary essential oils (EOs) on productive performance, nutrient digestibility, and serum metabolite profiles of broiler chickens and to compare their effectiveness as growth-promoting additives against antibiotics.

METHODS

Peer-reviewed articles were retrieved from Web of Science, Science Direct, PubMed, and Google scholar and selected based on pre-determined criteria. A total of 41 articles containing 55 experiments with 163 treatment units were eligible for analyses. Data were subjected to a meta-analysis based on mixed model methodology considering the doses of EOs as fixed effects and the different studies as random effects.

RESULTS

Results showed a linear increase (p<0.001) on body weight gain (BWG) where Antibiotics (FCR) and average daily feed intake decreased (p<0.001) linearly with an increasing dose of EOs. Positive effects were observed on the increased (p<0.01) digestibility of dry matter, crude protein, ether extract, and cecal Lactobacillus while Escherichia coli (E. coli) population in the cecum decreased (p<0.001) linearly. There was a quadratic effect on the weight of gizzard (p<0.01), spleen (p<0.05), bursa of fabricius (p<0.001), and liver (p< 0.10) while carcass, abdominal fat, and pancreas increased (p<0.01) linearly. The dose of EOs linearly increased high density lipoprotein, glucose, protein, and globulin concentrations (p<0.01). In comparison to control and antibiotics, all type of EOs significantly reduced (p<0.001) FCR and tended to increase (p<0.1) BWG and final body weight. Cinnamaldehyde-compound was the only EOs type showing a tendency to increase (p<0.1) carcass weight, albumin, and protein of serum metabolites while this EOs together with EOs-Blend 1 decreased (p<0.01) E. coli population. Low density lipoprotein concentration decreased (p<0.05) with antibiotics and carvacrol-based compound when compared to the control group.

CONCLUSION

This evidence confirms that EOs are suitable to be used as growth promoters and their economical benefit appears to be promising.

The effects of dietary supplementation with lotus leaf extract on the immune response and intestinal microbiota composition of broiler chickens

This study aimed to assess the effect of lotus leaf extract (LLE) on the immune response and intestinal microbiota composition of broiler chickens. One-day-old birds were assigned to 7 treatments. Two maize-based control diets were each given with or without 50 mg/kg chlortetracycline (antibiotics and blank control groups, respectively). Five experimental diets were each given with 1.0, 2.5, 5.0, 7.5, or 10.0 g/kg LLE. Average daily weight gain (ADG) was assessed, and the immune organ index was calculated. Serum cytokine and immunoglobulin levels were determined, and intestinal microbiota composition was analyzed via high-throughput sequencing of the 16S rRNA gene. Results showed that in the LLE5 group, ADG was higher than that of the antibiotics and blank control groups (P < 0.05) from d 7 to 21, the thymus index at d14, spleen index at d 21, and bursa index at d 14 and 21 were increased markedly (P < 0.05). In the LLE5 and LLE7.5 groups, serum total IgG and sIgA concentrations were higher than those of the antibiotics and blank control groups (P < 0.05) at d 7 and higher than those of the antibiotics group (P < 0.05) at d 14. No significant effect was observed for interferon-gamma concentrations between the antibiotics and LLE5 or LLE7.5 groups; compared with the antibiotics group, IL2 concentrations were increased in the LLE5 group at d 7 and in the LLE7.5 group at d 21 (P < 0.05). 16s rRNA sequencing analysis revealed that there were 1,704, 232, and 4,814 operational taxonomic unit in the blank control group, antibiotics group, and LLE groups, respectively. The intestinal microbiota consisted mainly of Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes (>95%) at the phylum level; at the family level, the abundance of Clostridiaceae and Bacteroidales S24-7 was increased, whereas that of Peptostreptococcaceae was reduced in LLE5 group (P < 0.05). These findings suggest that LLE may be a good source of prebiotics, helping to modulate the immune response and boost the levels of beneficial bacteria.

Emulsifier and Xylanase Can Modulate the Gut Microbiota Activity of Broiler Chickens

Simple Summary

Modern broiler nutrition, due to widely accepted goals of sustainable production, is concerned with the improvement of nutrient utilization. To achieve this, in our study, we used feed additives that improve the value of feed components. Due to the significant amounts of non-starch polysaccharides (which are not digested under broiler intestinal tract conditions and negatively affect broilers performance) in popular feed components like wheat, enzymes are needed. Furthermore, the use of emulsifiers to improve fat digestion is necessary, as young birds do not secrete sufficient enzyme and bile salts. Previous studies have shown that an additional increase in carbohydrate digestibility can be obtained by using an emulsifier containing xylanase in the feed. Presumably, the increase in carbohydrate digestibility occurred after adding the emulsifier. In our study, we aimed to investigate the effect of xylanase, emulsifier, and a combination of both in wheat diets with high level of tallow on the gastrointestinal tract microbiota activity of 480 one-day-old male ROSS 308 broiler chickens. The simultaneous usage of both additives in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Abstract

In this study, we aimed to investigate the effect of xylanase (XYL), emulsifier (EMU), and a combination of both (XYL + EMU) in wheat diet with a high level of tallow on gastrointestinal tract microbiota activity, excretion of sialic acids, and selected gut segments morphology of 480 one-day-old male ROSS 308 broiler chickens. The activities of bacterial enzymes in the ileal digesta were lower in experimental groups compared to the control (CON) group. Enzyme activity in the cecum was significantly higher than in the ileum. The additives did not affect the excretion of sialic acid. The number of duodenum goblet cells on the villi decreased in all of the experimental groups (p < 0.05). The simultaneous use of XYL + EMU deepened the ileum crypts (p < 0.05). The total short-chain fatty acid (SCFA) concentration in the cecal digesta was higher in experimental groups. The abundance of Bifidobacterium, Lactobacillus, and Escherichia coli did not change among experimental groups. The relative abundance of Clostridium was significantly (p < 0.05) lower in groups with emulsifier addition. In conclusion, the simultaneous usage of EMU and XYL in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Sustainable Antibiotic-Free Broiler Meat Production: Current Trends, Challenges, and Possibilities in a Developing Country Perspective

Simple Summary

Chickens are raised with the assistance of the regular use of antibiotics, not only for the prevention and treatment of diseases but, also, for body growth. Overuse and misuse of antibiotics in animals are contributing to the rising threat of antibiotic resistance. Therefore, antibiotic-free broiler meat production is becoming increasingly popular worldwide to meet consumer demand. However, numerous challenges need to be overcome in producing antibiotic-free broiler meat by adopting suitable strategies regarding food safety and chicken welfare issues. This review focuses on the current scenario of antibiotic use, prospects, and challenges in sustainable antibiotic-free broiler meat production. We also discuss the needs and challenges of antibiotic alternatives and provide a future perspective on antibiotic-free broiler meat production.

Abstract

Antibiotic-free broiler meat production is becoming increasingly popular worldwide due to consumer perception that it is superior to conventional broiler meat. Globally, broiler farming impacts the income generation of low-income households, helping to alleviate poverty and secure food in the countryside and in semi-municipal societies. For decades, antibiotics have been utilized in the poultry industry to prevent and treat diseases and promote growth. This practice contributes to the development of drug-resistant bacteria in livestock, including poultry, and humans through the food chain, posing a global public health threat. Additionally, consumer demand for antibiotic-free broiler meat is increasing. However, there are many challenges that need to be overcome by adopting suitable strategies to produce antibiotic-free broiler meat with regards to food safety and chicken welfare issues. Herein, we focus on the importance and current scenario of antibiotic use, prospects, and challenges in the production of sustainable antibiotic-free broiler meat, emphasizing broiler farming in the context of Bangladesh. Moreover, we also discuss the need for and challenges of antibiotic alternatives and provide a future outlook for antibiotic-free broiler meat production.

The optimization of fermentation conditions for Pichia pastoris GS115 producing recombinant xylanase

Xylanase is a member of an important family of enzymes that has been used in many biotechnological processes. However, the overall cost of enzyme production has been the main problem in the industrial application of enzymes. To obtain maximum xylanase production, statistical approaches based on the Plackett-Burman design and response surface methodology were employed. The results of the statistical analyses demonstrated that the optimal conditions for increased xylanase production were the following: inoculum size, 3.8%; maize meal, 4.5%; histidine, 0.6%; methanol, 1%; culture volume, 20%; bean pulp, 30 g L-1; and Tween-80, 0.8%; and pH 5.0. Verification of the optimization demonstrated that 3273 U mL-1 xylanase was observed under the optimal conditions in shake flask experiments. SDS-PAGE results showed that the size of xylanase protein was about 23 kDa. The results showed that the xylanase produced by fermentation came from Aspergillus Niger by MALDI-TOF-MS. The optimized medium resulted in 2.1- and 1.4-fold higher the activity of xylanase compared with the unoptimized medium (the main nutrients are maize meal and bean pulp) and laboratory medium (the main nutrients are yeast extract and peptone), respectively. The optimization of fermentation conditions is an effective means to reduce production cost and improve xylanase activity.

Dietary encapsulated essential oils and organic acids mixture improves gut health in broiler chickens challenged with necrotic enteritis

Background

The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis (NE) due to Clostridium perfringens. In the present study, we investigated the effects of dietary supplementation with a blend of encapsulated essential oils and organic acids (BLJ) on growth performance and gut health using a coinfection model of NE in broiler chickens.

Methods

Two hundred and eighty-eight one-day-old male Arbor Acres broiler chicks were randomly assigned using a 2 × 2 factorial design into two groups fed either 0 or 500 mg/kg dietary BLJ and co-challenged (or not challenged for the control) with Eimeria spp./C. perfringens.

Results

Infected birds fed the BLJ-supplemented diet exhibited an improved feed conversion ratio throughout the trial (P < 0.01), a higher villus height and villus height/crypt depth ratio, and reduced intestinal C. perfringens counts, liver C. perfringens carriage, gut lesion scores and serum fluorescein isothiocyanate dextran (FITC-D) concentrations at 7 d post-infection compared with those of birds without BLJ supplementation (P < 0.05). NE-infected birds fed BLJ exhibited significantly upregulated claudin-1 and IGF-2 mRNA levels (P < 0.05), increased A20 mRNA expression and significantly downregulated TRAF-6, TNFSF15 and TOLLIP mRNA levels in the jejunum at 7 d post-infection compared with those in birds without BLJ supplementation (P < 0.05). Compared with the uninfected and untreated birds, the uninfected birds fed BLJ displayed increased relative abundances of Lactobacillus and Coprococcus but reduced Rikenellaceae levels. Compared with the unsupplemented NE-challenged birds, infected birds fed BLJ showed an increased relative abundance of Unclassified_Lachnospiraceae and a significantly decreased relative abundance of Erysipelotrichaceae.

Conclusion

BLJ supplementation improved growth performance and gut health in NE-infected broiler chickens by strengthening the intestinal barrier function, positively modulating the gut microbiota community and differentially regulating intestinal immune responses. Our results also suggested that adding BLJ effectively controlled NE infections after experimental Eimeria and Clostridium perfringens coinfection.

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0-35 d broiler chicken diets. 2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source. 3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0-35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001). 4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.

Dietary supplement of essential oil from oregano affects growth performance, nutrient utilization, intestinal morphology and antioxidant ability in Pekin ducks

A study was conducted to investigate the effects of oregano essential oil (EO) on growth performance, nutrients utilization, intestinal morphology, intestinal barrier-related gene expression and antioxidant capability in meat ducks. A total of 360 1-day-old ducks were divided into three groups (12 replicates pens per diet of 10 ducks in each pen): negative control (no essential oil or antibiotic), positive control (antibiotic: 500 mg/kg aureomycin of diet) and oregano EO (100 mg/kg of diet). The experiment was carried out for 35 days. Ducks were given feed and water ad libitum. Ducks fed EO supplement showed similar body weight and feed to gain ratio to antibiotic fed ducks. EO supplementation significantly increased (p < .05) feed intake (day 1-35), jejunal villus height (VH) to crypt depth (CD) ratio, serum superoxide dismutase activities (SOD) and jejunal total antioxidant capacity (T-AOC) of ducks compared to controls. Ducks fed diets supplemented with oregano EO also had decreased (p < .05) jejunal CD, serum and hepatic malondialdehyde (MDA) concentration, and the mRNA expression of jejunal zonula occludens-3 (ZO-3) and secretory immunoglobulin A (sIgA) genes in comparison to the control group. Compared to the antibiotic supplementation group, the mRNA expression of claudin1 (CLND1) and CLND2 significantly increased (p < .05), but the mRNA expression of ZO-3 and mucin 2 markedly decreased (p < .05) in the jejunum of ducks in oregano EO supplementation group. These results suggest that oregano EO improves the antioxidant capacity and intestinal defence and structural measures and may aide in helping to maintain enteric health in production without growth-promoting antibiotics.

Immune modulation, growth performance, and nutrient retention in broiler chickens fed a blend of phytogenic feed additives

This study aimed to assess the effect of a commercial blend of phytogenic feed additives (PA), comprising 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin on the modulation of immune biomarkers of broiler chickens, their growth performance, dietary energy, and nutrient retention. Four-hundred day-old birds were assigned to one of four dietary treatments. Two control diets based on either wheat (WC) or maize (MC) were each given with and without PA at 100 g/t. Growth performance variables including feed intake (FI), weight gain (WG), and feed conversion ratio (FCR) were recorded. Dietary N-corrected apparent metabolizable energy (MEn), dry matter (DMR), nitrogen (NR), and fat retention (FR) coefficients were also determined. Gene expression of immune biomarkers (cytokines) were determined in caecal tonsil tissue from 21 d old birds. Expression of IL2, IL18, IL10, and IL17C in the caecal tonsils were upregulated (P < 0.05) in the birds fed MC-based diets compared to the WC fed birds. Feeding PA supplemented diets downregulated the expression of CD40LG (P < 0.001), IFNG, and IL6 (P < 0.05). There was a cereal type × PA interaction (P < 0.05), as expression of IFNB was downregulated in the birds fed PA supplemented MC but not WC. However, expression of IL12B was downregulated in birds fed PA supplemented WC but there was no significant (P > 0.05) change in expression levels in birds fed MC diets. Feeding MC diets gave greater FI (P < 0.001) and ME (P < 0.05), but lower FCR (P < 0.05) compared to birds fed WC diets. The WG and nutrient retention coefficients were not affected (P > 0.05) by cereal type. Supplementary PA improved FI (P < 0.05), WG (P < 0.001), FCR (P < 0.05), MEn (P < 0.05), MEn: GE ratio (P < 0.05), and FR (P < 0.05). In conclusion, dietary inclusion of PA improved overall growth performance variables, energy, and nutrient retention and intestinal cytokine expression.

Use of antibiotics in broiler production: Global impacts and alternatives

Antibiotics are used to fight bacterial infections. However, a selective pressure gave rise to bacteria resistant to antibiotics. This leaves scientists worried about the danger to human and animal health. Some strategies can be borrowed to reduce the use of antibiotics in chicken farms. Much research has been carried out to look for natural agents with similar beneficial effects of growth promoters. The aim of these alternatives is to maintain a low mortality rate, a good level of animal yield while preserving environment and consumer health. Among these, the most popular are probiotics, prebiotics, enzymes, organic acids, immunostimulants, bacteriocins, bacteriophages, phytogenic feed additives, phytoncides, nanoparticles and essential oils.

Impact of essential oils and organic acids on the growth performance, digestive functions and immunity of broiler chickens

The aim of the experiment was to study the effects of feeding blends of sorbic acid, fumaric acid, and thymol (EOA) on growth performance, digestive functions, and immunity of broiler chickens. A total of 640 one-day-old male Cobb 500 chicks with similar BW (41.8 ± 0.6 g) were randomly divided into 4 dietary treatment groups consisting of 10 replicates with 16 birds per replicate and fed a basal diet until d 42 (CON) or diets with 0.15 g/kg enramycin during the grower period (AG), 0.30 g/kg EOA during the grower period (EG), or 0.30 g/kg EOA during the finisher period (EF). At d 42, the feed conversion ratio was reduced (P < 0.05) for birds in EG group compared with other groups. Birds in EG group showed a higher villus height of the duodenum and jejunum and muscular layers of the duodenum and ileum than birds in CON group (P < 0.05). Compared with other groups, crypt depth of the jejunum and ileum was markedly increased (P < 0.05) by EOA supplementation during the finisher period at d 42. The EOA supplementation during grower period increased significantly lipase, trypsin and chymotrypsin activities of the duodenum at d 21 and 42, as well as lipase and trypsin at d 21, and trypsin and chymotrypsin at d 42 in the jejunum, and trypsin and chymotrypsin activities of the ileum at d 21 compared to the control diet (P < 0.05). Birds of EG and EF groups showed a higher (P < 0.05) spleen index than birds of CON group. The level of secretory immunoglobulin A in duodenal and ileal mucosa was increased (P < 0.05) in EF group at d 42 compared with other groups. In conclusion, the results indicate that EOA can be effectively applied in broiler diets, especially during the grower phase by improving intestinal morphology and increasing digestive enzyme activity.

Chemistry, Antimicrobial Mechanisms, and Antibiotic Activities of Cinnamaldehyde against Pathogenic Bacteria in Animal Feeds and Human Foods

Cinnamaldehyde is a major constituent of cinnamon essential oils produced by aromatic cinnamon plants. This compound has been reported to exhibit antimicrobial properties in vitro in laboratory media and in animal feeds and human foods contaminated with disease-causing bacteria including Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. This integrated review surveys and interprets our current knowledge of the chemistry, analysis, safety, mechanism of action, and antibiotic activities of cinnamaldehyde in food animal (cattle, lambs, calves, pigs, poultry) diets and in widely consumed liquid (apple, carrot, tomato, and watermelon juices, milk) and solid foods. Solid foods include various fruits (bayberries, blueberries, raspberries, and strawberries), vegetables (carrots, celery, lettuce, spinach, cucumbers, and tomatoes), meats (beef, ham, pork, and frankfurters), poultry (chickens and turkeys), seafood (oysters and shrimp), bread, cheese, eggs, infant formula, and peanut paste. The described findings are not only of fundamental interest but also have practical implications for food safety, nutrition, and animal and human health. The collated information and suggested research needs will hopefully facilitate and guide further studies needed to optimize the use of cinnamaldehyde alone and in combination with other natural antimicrobials and medicinal antibiotics to help prevent and treat food animal and human diseases.

Molecular Cloning and Characterizations of Xylanase Inhibitor Protein from Wheat (Triticum Aestivum)

Xylanase inhibitor proteins (XIPs) were regarded to inhibit the activity of xylanases during baking and gluten-starch separation processes. To avoid the inhibition to xylanases, it is necessary to define the conditions under which the inhibition takes place. In this study, we cloned the XIP gene from 2 different variety of Triticum aestivum, that is, Zhengmai 9023 and Zhengmai 366, and investigated the properties of XIP protein expressed by Pichia pastoris. The results showed that the 2 XIP genes (xip-9023 and xip-366) were highly homologous with only 3 nucleotide differences. XIP-9023 showed the optimal inhibition pH and temperature were 7 °C and 40 °C, respectively. Inhibition of xylanase by XIP-9023 reached the maximum in 40 min. At 50% inhibition of xylanase, the molar ratio of inhibitor: xylanase was 26:1. XIP-9023 was active to various fungal xylanases tested as well as to a bacterial xylanase produced by Paenibacillus sp. isolated from cow rumen.

Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review

With the increase in regulations regarding the use of antibiotic growth promoters and the rise in consumer demand for poultry products from ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ flocks, the quest for alternative products or approaches has intensified in recent years. A great deal of research has focused on the development of antibiotic alternatives to maintain or improve poultry health and performance. This review describes the potential for the various alternatives available to increase animal productivity and help poultry perform to their genetic potential under existing commercial conditions. The classes of alternatives described include probiotics, prebiotics, synbiotics, organic acids, enzymes, phytogenics, antimicrobial peptides, hyperimmune egg antibodies, bacteriophages, clay, and metals. A brief description of the mechanism of action, efficacy, and advantages and disadvantages of their uses are also presented. Though the beneficial effects of many of the alternatives developed have been well demonstrated, the general consensus is that these products lack consistency and the results vary greatly from farm to farm. Furthermore, their mode of action needs to be better defined. Optimal combinations of various alternatives coupled with good management and husbandry practices will be the key to maximize performance and maintain animal productivity, while we move forward with the ultimate goal of reducing antibiotic use in the animal industry.