Antimicrobial Growth Promoters Research Articles

Characterization of cow urine for antimicrobial properties and plant growth promoter in rice (Oryza sativa L.)

Characterization of cow urine for antimicrobial properties and plant growth promoter in rice (Oryza sativa L.)

Effect of an immune challenge and two feed supplements on broiler chicken individual breast muscle protein synthesis rate

Optimization of broiler chicken breast muscle protein accretion is key for the efficient production of poultry meat, whose demand is steadily increasing. In a context where antimicrobial growth promoters use is being restricted, it is important to find alternatives as well as to characterize the effect of immunological stress on broiler chicken's growth. Despite its importance, research on broiler chicken muscle protein dynamics has mostly been limited to the study of mixed protein turnover. The present study aims to characterize the effect of a bacterial challenge and the feed supplementation of citrus and cucumber extracts on broiler chicken individual breast muscle proteins fractional synthesis rates (FSR) using a recently developed dynamic proteomics pipeline. Twenty-one day-old broiler chickens were administered a single 2H2O dose before being culled at different timepoints. A total of 60 breast muscle protein extracts from five experimental groups (Unchallenged, Challenged, Control Diet, Diet 1 and Diet 2) were analysed using a DDA proteomics approach. Proteomics data was filtered in order to reliably calculate multiple proteins FSR making use of a newly developed bioinformatics pipeline. Broiler breast muscle proteins FSR uniformly decreased following a bacterial challenge, this change was judged significant for 15 individual proteins, the two major functional clusters identified as well as for mixed breast muscle protein. Citrus or cucumber extract feed supplementation did not show any effect on the breast muscle protein FSR of immunologically challenged broilers. The present study has identified potential predictive markers of breast muscle growth and provided new information on broiler chicken breast muscle protein synthesis which could be essential for improving the efficiency of broiler chicken meat production. SignificanceThe present study constitutes the first dynamic proteomics study conducted in a farm animal species which has characterized FSR in a large number of proteins, establishing a precedent for biomarker discovery and assessment of health and growth status. Moreover, it has been evidenced that the decrease in broiler chicken breast muscle protein following an immune challenge is a coordinated event which seems to be the main cause of the decreased growth observed in these animals.

Investigating antibiotic free feed additives for growth promotion in poultry: effects on performance and microbiota

The poultry industry is evolving towards antibiotic-free production to meet market demands and decelerate the increasing spread of the antimicrobial resistance. The growing need for antibiotic free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in broiler diet to improve feed efficiency, growth rate, and intestinal health. Natural feed additives (e.g., probiotics and phytobiotics) are promising alternatives to substitute antimicrobial growth promoters. The goal of our study was to characterize the effects of a Probiotic and an Essential Oils blend on broilers' performance and perform a time-series analysis to describe their excreta microbiome. A total of 320 Cobb 500 (1-day-old) chicks were raised for 21 d in 32 randomly allocated cages. Treatments consisted of 4 experimental diets: a basal diet, and a basal diet mixed with an Antibiotic (bacitracin methylene disalicylate), an essential oils blend (oregano oil, rosemary, and red pepper), or a Probiotic (Bacillus subtilis). Body weight (on 1, 10, and 21d), and feed intake (10d and 21d) were recorded and feed conversion ratio was calculated. Droppings were collected daily (1-21d) to characterize broilers' excreta microbiota by targeted sequencing of the bacterial 16S rRNA gene. The Probiotic significantly improved feed conversion ratio for starter phase 1 to 10d (P = 0.03), grower phase 10 to 21d (P = 0.05), and total period 1 to 21d (P = 0.01) compared to the Antibiotic. Feed supplements did not affect alpha diversity but did impact microbial beta diversity (P < 0.01). Age also impacted microbiome turnover as differences in alpha and beta diversity were detected. Furthermore, when compared to the basal diet, the probiotic and antibiotic significantly impacted relative abundance of Bifidobacterium (log2 fold change -1.44, P = 0.03), Intestinimonas (log2 fold change 0.560, P < 0.01) and Ligilactobacillus (log2 fold change -1.600, P < 0.01). Overall, Probiotic supplementation but not essential oils supplementation positively impacted broilers' growth performance by directly causing directional shifts in broilers' excreta microbiota structure.

Bacillus amyloliquefaciens Probiotics Mix Supplementation in a Broiler Leaky Gut Model.

The supplementation of antimicrobial growth promoters (AGPs) has been banned in many countries because of the emergence of antimicrobial-resistant pathogens in poultry products and the environment. Probiotics have been broadly studied and demonstrated as a promising AGP substitute. Our study is centred on the effects of a multi-strain Bacillus-based probiotic product on broiler production performance and gut microbial profile in a dexamethasone-induced leaky gut challenge. Two hundred and fifty-six broiler chicks were hatched and randomly assigned into four groups (wheat-soybean meal basal diet (BD) = non-supplemented control (C), BD supplemented with dexamethasone in week 4 (CD), BD containing a probiotic from day one (P), and BD containing a probiotic from day one and supplemented with dexamethasone during challenge week 4 (PD)). The production performance and caecal, gizzard, jejunal lumen and jejunal mucosa swab microbiota were studied by 16S rRNA gene sequencing. The Bacillus probiotic product significantly improved production performance and altered caecal gut microbiota (p ≤ 0.05), but no significant impact on microbiota was observed in other gut sections.

Alterations of rumen and fecal microbiome in growing beef and dairy steers fed rumen-protected Capsicum oleoresin.

The microbiome has been linked to animal health and productivity, and thus, modulating animal microbiomes is becoming of increasing interest. Antimicrobial growth promoters (AGP) were once a common technology used to modulate the microbiome, but regulation and consumer pressure have decreased AGP use in food animals. One alternative to antimicrobial growth promoters are phytotherapeutics, compounds derived from plants. Capsaicin is a compound from the Capsicum genus, which includes chili peppers. Capsaicin has antimicrobial properties and could be used to manipulate the gastrointestinal microbiome of cattle. Both the rumen and fecal microbiomes are essential to cattle health and production, and modulation of either microbiome can affect both cattle health and productivity. We hypothesized that the addition of rumen-protected capsaicin to the diet of cattle would alter the composition of the fecal microbiome, but not the rumen microbiome. To determine the impact of rumen-protected capsaicin in cattle, four Holstein and four Angus steers were fed rumen-protected Capsicum oleoresin at 0 (Control), 5, 10, or 15mg kg-1 diet dry matter. Cattle were fed in treatment groups in a 4 × 4 Latin Square design with a 21-d adaptation phase and a 7-d sample collection phase. Rumen samples were collected on day 22 at 0-, 2-, 6-, 12-, and 18-h post-feeding, and fecal swabs were collected on the last day of sample collection, day 28, within 1h of feeding. Sequencing data of the 16s rRNA gene was analyzed using the dada2 pipeline and taxa were assigned using the SILVA database. No differences were observed in alpha diversity among fecal or rumen samples for either breed (P > 0.08) and no difference between groups was detected for either breed in rumen samples or for Angus steers in fecal samples (P > 0.42). There was a difference in beta diversity between treatments in fecal samples of Holstein steers (P < 0.01), however, a pairwise comparison of the treatment groups suggests no difference between treatments after adjusting for multiple comparisons. Therefore, we were unable to observe substantial overall variation in the rumen or fecal microbiomes of steers due to increasing concentrations of rumen-protected capsaicin. We do, however, see a trend toward increased concentrations of capsaicin influencing the fecal microbiome structure of Holstein steers despite this lack of significance.

Effects of feeding eubiotics as antibiotic substitutes on growth performance, intestinal histomorphology and microbiology of broilers

The inclusion of prebiotics and/or probiotics in broiler diets as a substitute for antibiotics is a topic of interest in poultry nutrition research due to concerns about antibiotic resistance and the need for sustainable poultry production practices. A total of 200 one-day-old chicks were housed in 40 cages, with eight cages repeated per treatment. Birds were fed a basal diet supplemented with one of five feed treatments at the following rates: 0 (control), 0.05 g Neoxyval/kg (antimicrobial growth promoter (AGP)), 0.2 g GalliPro®/kg (probiotic), 0.6 g TechnoMos®/kg (prebiotic) and a mixture of 0.2 g GalliPro®/kg + 0.6 g TechnoMos®/kg (symbiotic). During 0–42 days, the growth performance of broilers, carcass characteristics and intestinal histomorphology were investigated. The AGP, prebiotic and probiotic-treated birds outperformed the control and symbiotic-treated groups in terms of body weight gain, feed conversion, performance index and feed efficiency. The birds given AGP and probiotics had the longest partial and total small intestine length, while the birds given prebiotics had the smallest. In addition, prebiotic-treated birds had longer ileum villi and higher ileal lactic acid bacteria colonies than control and AGP-treated birds. Clostridium perfringens was eradicated from the ileum by probiotics, but not from the caecum. In conclusion, probiotics and prebiotics can be used as an alternative to antibiotics in broiler diets.

Review on Semecarpus Anacardium Linn

Since ancient times, Semecarpus anacardium Linn. (Family: Anacardiaceae), also known as "Ballataka" or "Bhilwa," has been utilized in numerous traditional systems of medicine for a variety of diseases.The biologically active substances found in its nuts, including biflavonoids, phenolic compounds, bhilawanols, minerals, vitamins, and amino acids, have a variety of therapeutic effects.The fruit and nut extract has a wide range of properties, including those that are antiatherogenic, anti-inflammatory, antioxidant, antimicrobial, anti-reproductive, CNS stimulant, hypoglycemic, anticarcinogenic, and hair growth promoter. The article discusses the plant's numerous operations in detail.

Current status and trends in antimicrobial use in food animals in China, 2018–2020

Antimicrobial resistance poses a significant threat to global public health, and excessive antimicrobial use (AMU) in animals is a major contributing factor. We used national AMU data for food animals to examine the current status and trends for AMU in food animals in China from 2018–2020. In 2020, China used 32,776.30 tons of antimicrobials in food animals, amounting to 165 g of antimicrobials per ton of animal products. AMU in China increased throughout the 2018–2020 study period; however, the data still showed a consistent and notable reduction from those of 2017, coinciding with the implementation of the China National Action Plan for Combating Animal Antimicrobial Resistance. Among the antimicrobials used, tetracyclines, macrolides and β-lactams (including β-lactam inhibitors) were the most commonly used in food animals. Analysis by antimicrobial class revealed shifts in usage patterns, such as decreased tetracycline use and increased macrolide and β-lactam use. Furthermore, the use of antimicrobial growth promoters decreased sharply, from 51.78% in 2018 to 28.7% in 2020. Compared with AMU data from other countries, China used more antimicrobials, but the values were relatively lower when adjusted for population correction units. These findings highlight China's remarkable efforts in combating antimicrobial resistance and promoting antimicrobial stewardship, thus contributing significantly to global initiatives.

Antimicrobial growth promoters approved in food-producing animals in South Africa induce shiga toxin-converting bacteriophages from Escherichia coli O157:H7.

In this study, four antimicrobial growth promoters, including virginiamycin, josamycin, flavophospholipol, poly 2-propenal 2-propenoic acid and ultraviolet light, were tested for their capacity to induce stx-bacteriophages in 47 Shiga toxin-producing E. coli O157:H7 isolates. Induced bacteriophages were characterized for shiga toxin subtypes and structural genes by PCR, DNA restriction fragment length polymorphisms (RFLP) and morphological features by electron microscopy. Bacteriophages were induced from 72.3% (34/47) of the STEC O157:H7 isolates tested. Bacteriophage induction rates per induction method were as follows: ultraviolet light, 53.2% (25/47); poly 2-propenal 2-propenoic acid, 42.6% (20/47); virginiamycin, 34.0% (16/47); josamycin, 34.0% (16/47); and flavophospholipol, 29.8% (14/47). A total of 98 bacteriophages were isolated, but only 59 were digestible by NdeI, revealing 40 RFLP profiles which could be subdivided in 12 phylogenetic subgroups. Among the 98 bacteriophages, stx2a, stx2c and stx2d were present in 85.7%, 94.9% and 36.7% of bacteriophages, respectively. The Q, P, CIII, N1, N2 and IS1203 genes were found in 96.9%, 82.7%, 69.4%, 40.8%, 60.2% and 73.5% of the samples, respectively. Electron microscopy revealed four main representative morphologies which included three bacteriophages which all had long tails but different head morphologies: long hexagonal head, oval/oblong head and oval/circular head, and one bacteriophage with an icosahedral/hexagonal head with a short thick contractile tail. This study demonstrated that virginiamycin, josamycin, flavophospholipol and poly 2-propenal 2-propenoic acid induce genetically and morphologically diverse free stx-converting bacteriophages from STEC O157:H7. The possibility that these antimicrobial growth promoters may induce bacteriophages in vivo in animals and human hosts is a public health concern. Policies aimed at minimizing or banning the use of antimicrobial growth promoters should be promoted and implemented in countries where these compounds are still in use in animal agriculture.

209 Prevalence of Antimicrobial Resistance Genes and Mobile Genetic Elements in the Swine Gut Microbiome

Abstract Antimicrobial resistance (AMR) is one of the most pressing threats to public health. It contributes to over a million deaths a year currently and by 2050 it is expected to cause more annual death than cancer. The swine industry has taken important steps to address the AMR crisis by phasing out the use of antimicrobial growth promoters. Nonetheless, the use of antimicrobials for controlling infectious diseases on swine farms remains high, particularly during the nursery stage of pig production. This has raised concerns about the potential role of the swine industry in the emergence and spread of antimicrobial resistance genes (ARGs) capable of conferring resistance to medically important antimicrobials. While traditionally ARGs have been studied in the context of pathogens, there is growing evidence that the natural microbiome of humans and animals can also serve as a significant reservoir of ARGs. Of particular importance is the association of ARGs with different classes of mobile genetic elements (MGEs) which can facilitate the horizontal transfer of genes among commensal bacteria and pathogens. In this study, we evaluated the diversity and distribution of ARGs and their associated MGEs in the swine gut microbiome. To achieve this, we isolated and sequenced the whole genomes of 130 unique bacterial isolates from stool, digesta, and mucosa of healthy adult sows and their piglets. Screening of genomes for the presence of ARGs was performed using the Resistance Gene Identifier (RGI) and Comprehensive Antibiotic Resistance Database (CARD), resulting in the identification of 323 ARGs across 117 genomes. Among these, genes predicted to confer resistance against tetracycline, lincosamide, beta-lactams, and fluoroquinolone were the most prevalent across all genomes. Importantly, we observed that several strictly anaerobic species belonging to gut-specific lineages including Lachnospiraceae, Megasphaeraceae, and Desulfovibrionaceae contained large ARGs pools spanning more than five different classes of antimicrobials. Further, we screened the flanking regions of ARGs for the presence of signature genes of MGEs including recombinases, phage integrases and capsids, and type IV secretion system. A total of 60 ARGs were identified to be associated with different classes of MGEs, including integrative and conjugative elements (ICEs; n = 30), bacteriophages (n = 8), integrative mobile elements (IMEs; n = 6), and plasmids (n = 3). Overall, our study highlights that ARGs, including those conferring resistance to medically important antimicrobials, are prevalent across different lineages of the swine gut microbiota. The association of the identified ARGs with MGEs warrants further in vitro experiments to evaluate the risk of transmission of resistance to zoonotic pathogens capable of infecting humans and animals.

Effects of High-Biotin Sample Interference on Antibody Concentrations in Sandwich Immunoassays.

The use of antimicrobial growth promoters (AGPs) is banned because of problems associated with drug residues in animal products and increased bacterial resistance. The immunization of chickens with specific antigens is a promising strategy for generating specific antibodies that can target a wide range of antibiotic-resistant bacteria and can be used as an alternative to antibiotics. Immunoglobulin Y (IgY) antibodies in a polyclonal antibody (pAb) format, when administered orally, modulate the ruminal microbiome and maintain animal health and performance; however, there are concerns pertaining to protein impurities and biotin concentrations in the samples. Signal amplification strategies involving the noncovalent interaction of biotin with streptavidin is extensively used in diagnosis and scientific research, particularly in enzyme-linked immunosorbent assays (ELISAs). However, the high concentrations of biotin in samples, especially in those derived from rich sources such as egg yolk, can pose challenges and potentially harm the accuracy of diagnostic tests and protein concentration measurements. This study aimed to evaluate the influence of biotin on the measurement of IgY in freeze-dried egg yolk samples obtained from immunized laying hens using immunoassays with biotin-avidin/streptavidin. The detection of IgY in yolk samples using ELISA with streptavidin-biotin binding could lead to misdiagnosis due to biotin interference; the level of interference varies with the specific assay conditions and the concentration of biotin in the yolk samples. An ELISA without streptavidin-biotin binding is advisable to avoid interactions between biotin and target proteins, prevent biotin interference with the results, and achieve more reliable and accurate results.

Development, validation, and implementation of an ultratrace analysis method for the determination of moenomycin A, in aquatic animal products.

Moenomycin A, an antimicrobial growth promoter widely used as an additive in aquaculture feedstuffs, has been restricted for use in the European Union and China due to its potential risk of promoting resistant strains of pathogenic bacteria and causing residues in aquatic animal products. Although methods for analyzing moenomycin A in feedstuffs have been developed, no established method exists for aquatic matrices. In this study, we present, for the first time, a sensitive and validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of moenomycin A in aquatic animal products. Samples were extracted using methanol and purified with the QuEChERS method employing C18 sorbent. The aliquot was dried under a nitrogen stream, reconstituted with methanol-water solvent, and analyzed by HPLC-MS/MS. The developed method exhibited good linearity (r2 > 0.995) over a wide concentration range (1-100μg/L) and a low limit of detection (1µg/kg). Average recoveries ranged between 70 and 110% at spiked concentrations of 1, 50, and 100μg/kg, with associated intra- and inter-day relative standard deviations of 1.25 to 7.32% (n = 6) and 2.91 to 10.08% (n = 3), for different representative aquatic animal production, respectively. To the best of our knowledge, this is the first reported HPLC-MS/MS method for the quantification of moenomycin A in aquatic animal products. The new approach was effectively employed in the analysis of moenomycin A across various aquatic samples.

Dietary coriander (Coriandrum sativum L) oil improves growth, nutrient utilization, antioxidant status, tissue histomorphology and reduces omega-3 fatty acid production in Nile tilapia (Oreochromis niloticus)

Coriander (Coriandrum sativum L.) is recently emerging as an antimicrobial growth promoter in aquafeed formulations. To assess the effect of coriander seed oil in the feed of Nile tilapia five iso-nitrogenous (crude protein 40%) and iso-lipidic (crude lipid 7%) diets were prepared with graded levels of coriander oil i. e., 0, 5, 10, 15 and 20 g/Kg referred as C0, C5, C10, C15 and C20, respectively. The fish were fed with the experimental diets twice daily for a period of 60 days in triplicate. After the feeding experiment, there observed a linear pattern in weight gain with the dietary coriander oil levels. The expression of hepatic insulin like growth factor 1 gene increased significantly in coriander oil supplemented groups in dose dependent manner in hepatic tissues of tilapia. The viscerosomatic and hepatosomatic index decreased significantly in the coriander oil treated groups. The crude protein contents increased significantly in the experimental groups; however, it did not vary significantly in between the groups. The crude lipid contents increased significantly in the last three groups (C10, C15 and C20) compared to C0 and C5. The serum glucose content decreased significantly in the last three groups i.e., C10, C15 and C20 coriander fed groups compared to C0. Whereas, the HDL level increased significantly in the 20 g/Kg treatment group compared to rest of the groups. Catalase activity increased significantly in the liver tissue of coriander oil treated groups compared to control. The liver histomorphology showed signs of storage of carbohydrate or lipid reserves in the form of vacuoles in the control group. However, in the coriander supplemented groups there was a reduction in hepatic vacuolar structures. The appearance of intestinal villi was enriched in coriander oil supplemented groups via branching. The Δ6/Δ5 desaturase increased significantly in the experimental groups compared to control. The Δ4 desaturase and elongase decreased significantly beyond 6.3% and 11.7% of coriander oil in the diet, respectively. There observed a significant increase in the percentage of saturated fatty acids in dose dependent manner. However, the unsaturated fatty acids including omega-3 fatty acids decreased significantly with an increase dose of coriander oil in feed of Nile tilapia. It can be concluded from the above study that coriander essential oil can be used for better growth performance, intestinal nutrient absorption, antioxidant activity and decreasing hyperglycemia in Nile tilapia. However, higher inclusion level (above 5 g/Kg) led to decrease in the wholebody omega-3 fatty acid production.

An Immobilized Form of a Blend of Essential Oils Improves the Density of Beneficial Bacteria, in Addition to Suppressing Pathogens in the Gut and Also Improves the Performance of Chicken Breeding.

Antimicrobial growth promoters (AGP) are used in chicken production to suppress pathogens in the gut and improve performance, but such products tend to suppress beneficial bacteria while favoring the development and spread of antimicrobial resistance. A green alternative to AGP with the ability to suppress pathogens, but with an additional ability to spare beneficial gut bacteria and improve breeding performance is urgently required. We investigated the effect of supplementation of a blend of select essential oils (cinnamon oil, carvacrol, and thyme oil, henceforth referred to as EO; at two doses: 200 g/t and 400 g/t feed) exhibiting an ability to spare Lactobacillus while exhibiting strong E. coli inhibition ability under in vitro tests and immobilized in a sunflower oil and calcium alginate matrix, to broiler chickens and compared the effects with those of a probiotic yeast (Y), an AGP virginiamycin (V), and a negative control (C). qPCR analysis of metagenomic DNA from the gut content of experimental chickens indicated a significantly (p < 0.05) lower density of E. coli in the EO groups as compared to other groups. Amplicon sequence data of the gut microbiome indicated that all the additives had specific significant effects (DESeq2) on the gut microbiome, such as enrichment of uncultured Clostridia in the V and Y groups and uncultured Ruminococcaceae in the EO groups, as compared to the control. LEfSe analysis of the sequence data indicated a high abundance of beneficial bacteria Ruminococcaceae in the EO groups, Faecalibacterium in the Y group, and Blautia in the V group. Supplementation of the immobilized EO at the dose rate of 400 g/ton feed improved body weight gain (by 64 g/bird), feed efficiency (by 5 points), and cellular immunity (skin thickness response to phytoheamagglutinin lectin from Phaseolus vulgaris by 58%) significantly (p < 0.05), whereas neither yeast nor virginiamycin showed a significant effect on performance parameters. Expression of genes associated with gut barrier and immunity function such as CLAUDIN1, IL6, IFNG, TLR2A, and NOD1 were significantly higher in the EO groups. This study showed that the encapsulated EO mixture can improve the density of beneficial microbes in the gut significantly, with concomitant suppression of potential pathogens such as E.coli and improved performance and immunity, and hence, has a high potential to be used as an effective alternative to AGP in poultry.

Investigation of Trehalose Supplementation Impacting Campylobacter jejuni and Clostridium perfringens from Broiler Farming.

In 2006, the European Commission banned the use of antibiotic promoters in animal feed. However, there is a new situation in poultry disease where it is necessary to study feed additives, which can overcome the diseases that were previously controlled through the addition of antibiotics and antimicrobial growth promoters in the feed. Therefore, trehalose was investigated to determine whether it impacts the growth performance and pathogenic bacteria (C. jejuni and C. perfringens) inoculation in broilers. In the first experiment, the tolerance of broilers to the addition of trehalose to their feed was investigated. There was no significant difference (p > 0.05) in body weight changes, daily weight gain, feed intake or feed conversion ratio during the feeding period. Within a 35-day feeding period, it was concluded that a trehalose dosage up to 10% does not exert a negative effect on broiler farming. Moreover, there was no significant difference (p > 0.05) in the broilers' growth performance, as well as C. jejuni and C. perfringens counts in the intestines and feces of broilers observed over a 5-week feeding period. However, Lactobacillus counts significantly increased in these groups with 3% and 5% trehalose supplementation. The findings indicate that trehalose supplementation in the feed cannot directly decrease C. jejuni and C. perfringens counts but may enhance gut health by raising Lactobacillus counts in chicken gut, particularly when enteropathogenic bacteria are present.

Utilization of certain unconventional feeds in poultry as natural alternatives to curb antimicrobial resistance

Poultry market has been demonstrating emerging potential as an efficient producer of meat with consumption occupying 40.6% of market globally. The requirement of animal protein is anticipated to grow continuously for meeting the requirements by ever-growing human population. To fulfill this demand, the major challenge encountered by poultry breeders was to fasten production in most efficient and economical way. Use of antibiotic growth promoter in feed help in augmenting poultry growth and alter gut microbiota. However, the growing concern of its likely fatal impacts on animal, food safety and on humans for developing microbial resistance; their use was restricted and banned in several countries. With insinuation of ban, several alternatives were explored for having potential growth promoting benefits without hampering the normal gut microbiota. Various phytobiotics, prebiotics, probiotics, organic acids and unconventional feed have positive effects on feed intake, efficiency and play a role as antimicrobial. However, the meager knowledge on availability and potential use of unconventional feeds as potent antimicrobial restricts its application. This review focuses on certain non-conventional feeds rich in specific bioactive compounds, which are attributed to modulate intestinal microbiota, their effects on growth performance and overall health status of poultry. The review aims to serve as a reference for young researchers and poultry industry to recognize alternative feed ingredients to be used as antimicrobial growth promoters minimizing competition between human and animal consumption.

Effects of Sihuang Zhili Granules on the Diarrhea Symptoms, Immunity, and Antioxidant Capacity of Poultry Challenged with Lipopolysaccharide (LPS).

A growing interest has been focused on Chinese herbs as alternatives to antimicrobial growth promoters, which are characterized by non-toxic side effects and drug resistance. The purpose of this study was to evaluate the effects of the Sihuang Zhili granule (abbreviated as Sihuang) on diarrhea, immunity, and antioxidation in poultry. Thirty male Leghorn chickens, aged 21 days, were randomly assigned to one of three groups with ten animals each. The control group (CON) received intraperitoneal saline injections, while the LPS-challenged group (LPS) and Sihuang intervention group (SH) received intraperitoneal injections of LPS (0.5 mg/kg of BW) and Sihuang (5 g/kg) at d 31, d 33, d 35, respectively. The control and LPS groups were fed a basal diet, while the SH group was fed a diet supplemented with Sihuang from d 21 to d 35. Analysis of the diarrhea index showed that the addition of Sihuang inhibited the increase in the diarrhea grade and the fecal water content caused by LPS, effectively alleviating poultry diarrhea symptoms. The results of the immune and antioxidant indexes showed that Sihuang significantly reduced the contents of the pro-inflammatory factors TNF- α and IL-1 β, as well as the oxidative stress markers ROS and MDA. Conversely, it increased the contents of the anti-inflammatory factors IL-4 and IL-10, along with the activities of antioxidant enzymes GSH-Px and CAT, thereby enhancing the immune and antioxidant abilities of chickens. Furthermore, Sihuang protected the chicken's ileum, liver, and immune organs from LPS invasion and maintained their normal development. In conclusion, this study confirmed the antidiarrheal effect of Sihuang in poultry farming and demonstrated its ability to improve poultry immunity and antioxidant capacity by modulating antioxidant enzyme activity and inflammatory cytokine levels.

The role of dietary monoglycerides and tributyrin in enhancing performance and intestinal health function in nursery piglets

This study was conducted to assess the effects of dietary monoglycerides and tributyrin on performance, blood metabolites, and intestinal health function in nursery piglets. A total of 96 crossbred entire male piglets (7.70 ± 0.49 kg) were allotted for 35 d in a complete block design to one of four treatments: (1) negative control (NC): no feed additive, (2) positive control (PC) containing 60 mg halquinol/kg diet, (3) diet containing 2 g monoglyceride blend/kg diet (MGD), and (4) diet containing 2 g tributyrin/kg diet (TBT). The growth phases were defined as pre-starter (day 0–20), and starter (day 20–35). No treatment effect on performance was observed. Pre-starter piglets fed NC showed higher diarrhoea occurrence (DO) than those fed PC and TBT (p < .05), and a lower DO was observed in starter piglets fed PC, MGD, and TBT compared to NC (p < .001). Pre-starter piglets fed TBT showed lower alkaline phosphatase concentration than in PC, and a lower aspartate aminotransferase concentration compared to PC and MGD (p < .05). Plasma urea concentration was higher in starter piglets fed MGD than in NC and TBT (p < .05). Piglets fed TBT showed higher jejunum villous height:crypt depth ratio than other treatments (p < .05). Piglets on MGD had higher ileum cellular infiltrate than in PC but lower Enterobacteriaceae family in the piglets jejunum compared to other treatments (p < .05). Our results suggest that dietary tributyrin improves intestinal function structures, without affecting the microbial population as exhibited in nursery piglets fed monoglyceride-based diets. HIGHLIGHTS The use of antimicrobial growth promoters has been widely banned in piglet diets. The feed additives tested appeared to be potential alternatives to antimicrobial growth promoters. Piglets fed a tributyrin diet showed improvements in the structure of the intestinal epithelium. Diets containing a blend of monoglycerides reduced the abundance of Enterobacteriaceae in nursery piglets.

Sodium Salicylate as Feed Additive in Broilers: Absence of Toxicopathological Findings.

Antimicrobial growth promoters (AGPs) in animal production have been related to the increase in multidrug-resistant bacteria. The AGP ban in many countries has highlighted the growing need for alternatives for feed additives. Considering the non-antibiotic anti-inflammatory theory of AGPs, chicks received three different doses of sodium salicylate (SS) in feed (10, 30, 90 mg/kg), basal diet (BD) was used as a negative control, and zinc bacitracin (ZB) was used as a positive control. Chicks were individually housed to increase the accuracy of the dose of SS ingested. Performance parameters and footpad dermatitis were evaluated weekly, while haematology, serum biochemistry, histopathology, and tibial dyschondroplasia were determined on Days 21 and 42. A linear dose-dependent decrease in haemoglobin concentration was observed, but the values were within the normal reference range. Among all the other evaluated parameters, no relevant differences between treatments were observed; however, not even the AGP group performed better than the control group. It is possible that the conditions in which the birds were raised were not stressful enough to allow for anti-inflammatories to demonstrate their beneficial effects on performance. Studies should be conducted where the animals are exposed to commercial conditions, as the presence of natural stressors could allow a better evaluation of the efficacy of the anti-inflammatory agent as a growth promoter.

Screening and characterization of Bacillus velezensis LB-Y-1 toward selection as a potential probiotic for poultry with multi-enzyme production property.

Bacillus spp. have gained increasing recognition as an option to use as antimicrobial growth promoters, which are characterized by producing various enzymes and antimicrobial compounds. The present study was undertaken to screen and evaluate a Bacillus strain with the multi-enzyme production property for poultry production. LB-Y-1, screened from the intestines of healthy animals, was revealed to be a Bacillus velezensis by the morphological, biochemical, and molecular characterization. The strain was screened out by a specific screening program, possessed excellent multi-enzyme production potential, including protease, cellulase, and phytase. Moreover, the strain also exhibited amylolytic and lipolytic activity in vitro. The dietary LB-Y-1 supplementation improved growth performance and tibia mineralization in chicken broilers, and increased serum albumin and serum total protein at 21 days of age (p < 0.05). Besides, LB-Y-1 enhanced the activity of serum alkaline phosphatase and digestive enzyme in broilers at 21 and 42 days of age (p < 0.05). Analysis of intestinal microbiota showed that a higher community richness (Chao1 index) and diversity (Shannon index) in the LB-Y-1 supplemented compared with the CON group. PCoA analysis showed that the community composition and structure were distinctly different between the CON and LB-Y-1 group. The beneficial genera such as Parasutterella and Rikenellaceae were abundant, while the opportunistic pathogen such as Escherichia-Shigella were reduced in the LB-Y-1 supplemented group (p < 0.05). Collectively, LB-Y-1 can be considered as a potential strain for further utilization in direct-fed microbial or starter culture for fermentation.