Growth Promoters In Animal Feed Research Articles

Astragalus polysaccharide: implication for intestinal barrier, anti-inflammation, and animal production.

Intestine is responsible for nutrients absorption and plays a key role in defending against various dietary allergens, antigens, toxins, and pathogens. Accumulating evidence reported a critical role of intestine in maintaining animal and human health. Since the use of antibiotics as growth promoters in animal feed has been restricted in many countries, alternatives to antibiotics have been globally investigated, and polysaccharides are considered as environmentally friendly and promising alternatives to improve intestinal health, which has become a research hotspot due to its antibiotic substitution effect. Astragalus polysaccharide (APS), a biological macromolecule, is extracted from astragalus and has been reported to exhibit complex biological activities involved in intestinal barrier integrity maintenance, intestinal microbiota regulation, short-chain fatty acids (SCFAs) production, and immune response regulation, which are critical for intestine health. The biological activity of APS is related to its chemical structure. In this review, we outlined the source and structure of APS, highlighted recent findings on the regulation of APS on physical barrier, biochemical barrier, immunological barrier, and immune response as well as the latest progress of APS as an antibiotic substitute in animal production. We hope this review could provide scientific basis and new insights for the application of APS in nutrition, clinical medicine and health by understanding particular effects of APS on intestine health, anti-inflammation, and animal production.

Tracing probiotic producing bacterial species from gut of buffalo (Bubalus bubalis), South-East-Asia.

Due to extensive application of antibiotics as growth promoters in animal feed, antimicrobial resistance has been increased. To overcome this challenge, rumen microbiologists search for new probiotics to improve the rate of livestock production. The present study was aimed to isolate and evaluate breed-specific lactic acid bacteria (LAB) as potential animal probiotics. The current study was conducted during 10 months from July 2020 to April 2021, in which a total of n=12 strains were isolated from different samples including milk, rumen, and feces of Nilli Ravi Buffaloes. These isolates were evaluated for their antimicrobial potential against common animal pathogens (Bacillus spp., E. coli, Staphylococcus aureus, Salmonella spp., Listeria spp.). All the isolates were identified using 16S rRNA gene sequencing and the phylogenetic analyses inferred that these strains showed close relations to the species of various genera; Enterococcus lactis, Pediococcus pentosaceus, Bacillus subtilis Weissella cibaria, Weissella soli, Bacillus tequilensis, Weissella bombi, Bacillus licheniformis, Lactococcus lactis, Bacillus megaterium, Lactobacillus ruminis, and Lactococcus lactis. NMCC-Ru2 has exhibited the enormous potential of antimicrobial activity, 28 mm, for Salmonella typhimurium;23 mm for Listeria monocytogenes 21 mm for E.coil. Highest resistance was seen in NMCC-Ru2 agasint test antbiotic, like 25.5 mm for Tetracycline. Overall results revesl that the probiotic profile of isolates was achieved using standard criteria, particularly with animal probiotic properties.

Effects of Graded Levels of Typha angustifolia Rhizomes on Intestinal Microflora, Immune System, and Growth Performance of Broiler Chickens

Introduction: The ability of growth-promoting antibiotics to accumulate in livestock products such as meat, eggs, and milk, and the antibiotic resistance conferred on bacteria has prompted researchers to turn to phyto-additives. The present study was designed to evaluate the potential of Typha angustifolia rhizome powder as an alternative to antibiotic growth promoters in broiler chicken. Materials and methods: For this purpose, 512 one-day-old chickens of the Cobb500 strain were randomly distributed in a completely randomized design of 8 treatments of 16 chicks replicated four times. Experimental rations consisted of incorporating into a control ration 1 g of Doxycycline® (0+), and 1, 2, 4, 6, 8, and 10 g of Typha angustifolia /kg of feed, respectively. Results: The main results revealed that feed intake was not significantly affected by the different treatments. Over the study period, supplementing chicken with 6 g of T. angustifolia/kg increased live weight and weight gain by about 6.72% and 6.82%, respectively, compared to the negative control. Similarly, this phyto-additive, at the incorporation rate of 6 g/kg, decreased the chicken feed conversion ratio by 12.83% compared to the control without additives. The 6 g of Typha angustifolia/kg of feed induced a significant increase in the weight, length, and density of the intestine as compared to the negative control ration. This phyto-additive, whatever the rate, significantly increased the number of lactic acid bacteria, and the digestibility of crude protein and dietary fiber compared to the negative control. Apart from the serum concentration of total cholesterol and high-density cholesterol, which increased significantly with 1 g of Typha angustifolia compared to the negative control, all the haemato-biochemical parameters were not significantly affected by this phyto-additive, whatever the incorporation rate. Conclusion: In the condition of the present study, it was concluded that 6 g of Typha angustifolia/kg of feed can be used as a substitute for antibiotics growth promoters in animal feed.

Feed Additives of Bacterial Origin as an Immunoprotective or Immunostimulating Factor – A Review

Abstract Since January 2006 when using antibiotics as growth promoters in animal feed has been banned scientists are looking for the best resolution to apply alternative substances. Extensive research into the health-promoting properties of probiotics and prebiotics has led to significant interest in the mechanisms of action of the combined administration of these feed additives as a synbiotic. Subsequent research has led to the development of new products. Among the most important health benefits of additives are: inhibiting the growth of pathogenic bacteria in the GI tract, maintenance of homeostasis, treatment of inflammatory bowel diseases, and increase in immunity. Specific immunomodulatory mechanisms of action are not well understood and the effect is not always positive, though there are no reports of adverse effects of these substances found in the literature. For this reason, research is still being conducted on their proper application. However, due to the difficulties of carrying out research on humans, evidence of the beneficial effect of these additives comes mainly from experiments on animals. The objective of the present work was to assess the effect of probiotics, prebiotics, and synbiotics, as well as new additives including postbiotics, proteobiotics, nutribiotics, and pharmabiotics, on specific immunomodulatory mechanisms of action, increase in immunity, the reduction of a broad spectrum of diseases.

Regulatory Effects of Combined Dietary Supplementation With Essential Oils and Organic Acids on Microbial Communities of Cobb Broilers.

The emergence and spread of antibiotic resistance genes in pathogenic microorganisms have resulted in many countries restricting the use of antibiotics as growth promoters in animal feed. The combined use of essential oils and organic acids can help maintain intestinal health, improve animal growth performance, and alleviate the negative effects of banned antibiotics for certain economically important animals. Although the modes of action for the combined dietary supplementation of essential oils and organic acids such as thymol-citric acid (EOA1) and thymol-butyric acid (EOA2) remain unclear, it is speculated that their activities are achieved through beneficial modulation of gastrointestinal microbial communities and inhibition of pathogen growth. In this study, 16S rDNA amplicon sequencing was used to analyze the effects of treatment with EOA1 and EOA2 on the jejunal, cecal, and fecal microbial communities of Cobb broilers while also evaluating effects over different broiler ages. The intestinal microbial communities of broilers developed with increasing age, and Lactobacillus gradually came to dominate the intestinal communities of treated broilers. Further, the microbial communities of feces were more complex than those of the jejuna and ceca. We systematically elucidate that the longitudinal changes in the intestinal microbial communities of Cobb broiler chickens at different ages. Meanwhile, we found that the addition of EOA1 or EOA2 to the diet: (1) inhibited the proliferation of Ralstonia pickettii and Alcaligenaceae in the jejuna on day 28, (2) promoted the colonization and growth of beneficial bacteria such as Lactobacillus, Clostridia, and Bacteroidia at various growth stages, and (3) enriched the abundance of certain microbiota functions, including biological pathways related to metabolism (e.g., enzyme families). Taken together, the results of this study demonstrate that EOA1 and EOA2 dietary supplementation can affect various microbial metabolic pathways related to the metabolism and absorption of nutrients via regulation of the intestinal microbial community structures of Cobb broilers.

English

Ever since the reduction of antimicrobial growth promoters in animal feed, infectious diseases have re-emerged in certain parts of the world, necrotic enteritis (NE) for one. The current study determines the protective efficacy of egg yolk antibodies (EYAs) in experimentally infected broiler chicken. Eighty (80), day-old broiler chickens were procured and divided into four groups (G1-G4). Group G1 served as a negative control, while G2 served as positive control viz infected with C. perfringens type A (1 x 10 8 cfu/ml) from days 17-19 of the experiment. Groups G3 and G4 immunized passively with anti-clostridial IgY @ 1 ml per bird between days 21-24 via oral route, while 22nd and 24th days via I/M route, respectively. Two killings were performed (days 26th and 35th) and the birds were observed for growth performance, hematology and serum biochemistry. The study results showed a statistically significant decrease in growth, hematology and serum protein values, while elevation in serum enzyme values of the birds in group G2 when compared to group G1. The groups G3 and G4 (passively immunized) showed the values less affected and close to the physiological ranges. Hence it was concluded that anti-clostridial EYAs (IgY) has ameliorative effects against experimental clostridial infection in broiler chicken.

A Review: Role of Inulin in Animal Nutrition

Inulin is an oligosaccharide which can be used in the animal diet as a functional fiber. Among other natural plant-derived fructans, inulin has so many beneficial effects on the immune system, lipid metabolism, and helps in mineral absorption and has the ability to balance the intestinal microbiota of animals. Increasing global meat demand and ban of antibiotics as growth promoters in animal feed due to its residual effects in human food are the factors driving the growth of inulin as a feed additive. As feed additive in animal feed inulin has a positive effect on intestinal health and have the potential to improve the immunity of livestock and poultry. From few years, inulin has been making headlines in animal nutrition, but it remains a little-known feed ingredient and is even less used in the feed industry. Therefore, the objective of this review is to provide recently applied knowledge to the researchers about the general beneficial functions of inulin in the animal body and its application in the animal feed industry.

Beneficial effects of Saccharomyces cerevisiae RC016 in weaned piglets: in vivo and ex vivo analysis.

Probiotics represents an alternative to replace antibiotics as growth promoters in animal feed and are able to control enteric bacterial diseases and to improve gut immunity. Saccharomyces cerevisiae RC016 showed previously inhibition/coagregation of pathogens) and mycotoxins adsorbent ability (aflatoxin B1, ochratoxin A and zearalenone). The aim of this work was to evaluate beneficial properties of S. cerevisiae RC016 in a non-inflammatory in vivo model in weaned piglets and in an intestinal inflammation ex vivo model induced by the mycotoxin deoxynivalenol (DON). Secretory immunoglobulin A (s-IgA) levels, intestinal cytokines, goblet cells and production parameters were evaluated in a pig model. For the in vivo assays, twelve pigs were weaned at 21 days and assigned to two groups: Control (n=6) and Yeast (n=6). Animals received yeast strain for three weeks. After 22 days the small intestine was recovered for determination of goblet cells and s-IgA. For the ex vivo assay, jejunal explants were obtained from 5 weeks old crossbred piglets and treated as follow: (1) control; (2) treated for 3 h with 10 μM DON used as an inflammatory stressor; (3) incubated with 107 cfu/ml yeast strain; (4) pre-incubated 1 h with 107 cfu/ml yeast strain and then treated for 3 h with 10 μM DON. CCL20, interleukin (IL)-1β, IL-8 and IL-22 gene expression was determined by qPCR. Oral administration of S. cerevisiae RC016 increased s-IgA, the number of goblet cells in small intestine and all the growth parameters measured. In the ex vivo model, the cytokine profile studied showed a potential anti-inflammatory effect of the administration of the yeast. In conclusion, S. cerevisiae RC016 is a promising candidate for feed additives formulation to improve animal growth and gut immune system. This yeast strain could be able to improve the gut health through counteracting the weaning-associated intestinal inflammation in piglets.

Organic acids in piglet nutrition – a review

The risk of developing cross-resistance of pathogens to antibiotics led to a ban on antibiotics as growth promoters in animal feed in the European Union since January 2006. In recent decades, acidifiers have been widely used as potential alternatives to antibiotics in the nursery pigs’ diet to overcome weaning stresses, prevent intestinal disturbances with diarrhea and to improve growth performance. Organic acids can reduce the digesta pH value in the gastrointestinal tract (GIT), converting the inactive pepsinogen to active pepsin and increase the protein utilization. Acidifiers also promote beneficial microbial growth in the GIT and reduce infection from harmful microorganisms. Moreover, dietary inclusion of organic acids and their salts for weaning pigs can reduce intestinal epithelia damage, increase intestinal occludin expression and decrease small intestinal permeability, and improve immune indexes. In conclusion, dietary supplementation with acidifiers can decrease economic loss for pig producers.

Alternatives to Antibiotics to Prevent Necrotic Enteritis in Broiler Chickens: A Microbiologist's Perspective.

Since the 2006 European ban on the use of antibiotics as growth promoters in animal feed, numerous studies have been published describing alternative strategies to prevent diseases in animals. A particular focus has been on prevention of necrotic enteritis in poultry caused by Clostridium perfringens by the use of microbes or microbe-derived products. Microbes produce a plethora of molecules with antimicrobial properties and they can also have beneficial effects through interactions with their host. Here we review recent developments in novel preventive treatments against C. perfringens-induced necrotic enteritis in broiler chickens that employ yeasts, bacteria and bacteriophages or secondary metabolites and other microbial products in disease control.

Lactobacillus rhamnosus RC007 with immune-modulatory properties in an experimental model of TNBS-induced colitis in mice. Potential use as a feed additive for pig production.

Lactobacillus rhamnosus RC007 with immune-modulatory properties in an experimental model of TNBS-induced colitis in mice. Potential use as a feed additive for pig production.

A review of 733 published trials on Bio-Mos®, a mannan oligosaccharide, and Actigen®, a second generation mannose rich fraction, on farm and companion animals.

SummaryMannan-oligosaccharides (MOS), as zootechnical feed ingredients, are widely used in animal nutrition. MOS has been commercially available since the launch of Bio-Mos® in the early 1990's and has a substantial body of scientific papers and practical examples of its efficacy. Since 1999, the use of MOS in animal feed has become more prominent, mainly due to the European ban on prophylactic antibiotic growth promoters in animal feed. MOS, with its ability to bind and limit the colonisation of gut pathogens, has proven to be an effective solution for antibiotic-free diets, as well as providing support for immunity and digestion. MOS has been shown to improve gastrointestinal health, thus improving wellbeing, energy levels and performance. Most MOS products, particularly those that have been scientifically developed, derive from the cell wall of the yeast,Saccharomyces cerevisiae. In 2009, a mannose-rich fraction (MRF) product was commercially launched as a ‘second generation’ of these MOS-type products, with enhanced activities in immune modulation and intestinal health. The purpose of this paper is to review the existing data on the benefits of MOS for all species of animals, discuss its mechanisms of actionin vivoand compare the benefits of using second generation MRF to original MOS.

A review and future potential approach for Campylobacter control in retail poultry meats

Campylobacteriosis is considered the most frequent zoonosis in humans, and the handling and/or consumption of poultry meat are considered the main source for human infection. Moreover, largely owing to the recent food authority ban on the use of antibiotic growth promoters in animal feed, it is now very important to look for new effective strategies to reduce the incidence of these bacteria in the host. Chicken intestines, and also the intestines of other animals, are the only sites where Campylobacter proliferates in meat. Therefore, the development of a novel approach for controlling Campylobacter could be a very valuable alternative strategy in the fight to eliminate these bacteria from the poultry meat chain. Key words: Poultry, meat, retail, Campylobacter, control, novel approach.

Comparative Effect of Different Commercial Herbal Growth Promotors on Performance, Minor Body Parts Weight and Immune Responce in Broilers

Antibiotics have been used in poultry to improve growth performance but due to their side effects European Union has banned use of antibiotic as growth promoters in animal feed in 2006. Such situations has resulted in search for natural and safe alternatives, therefore, this study was undertaken to compare the efficacy of commercial herbal growth promoter as dietary inclusion on performance, minor body parts weight and immune response in broiler. A total of 120 healthy day old Hubbard chicks of uniform body weight were divided into 12 experimental units of 10 chicks each. These experimental units were further allotted to 4 treatment groups (T1, T2, T3 and T4) such that each treatment received 3 replicates. Group A was fed ration without supplementation of commercial herbal products i.e. control whereas group B, C and D were fed ration supplemented with commercial herbal products i.e. Bio-Mix, Respecine and A one Formula respectively each @ 100 g/ 50 kg of commercial feed. Each experimental unit of the chicks was reared in a separate pen. The birds were kept under similar managerial conditions. Feed intake, weight gain and FCR was better in group C fed respecine supplemented diet (P 0.05). Use of various commercial herbal growth promoters in the ration exhibited an increase in the profit margin of broilers. Broilers reared on respecine fetched maximum profit as compared to other groups.

Effects of mannan oligosaccharide and virginiamycin on the cecal microbial community and intestinal morphology of chickens raised under suboptimal conditions.

There is an increasing movement against use of antibiotic growth promoters in animal feed. Prebiotic supplementation is a potential alternative to enhance the host's natural defense through modulation of gut microbiota. In the present study, the effect of mannan oligosaccharide (MOS) and virginiamycin (VIRG) on cecal microbial ecology and intestinal morphology of broiler chickens raised under suboptimal conditions was evaluated. MOS and VIRG induced different bacterial community structures, as revealed by denaturing gradient gel electrophoresis of 16S rDNA. The antibiotic treatment reduced cecal microbial diversity while the community equitability increased. A higher bacterial diversity was observed in the cecum of MOS-supplemented birds. Quantitative polymerase chain reaction results indicated that MOS changed the cecal microbiota in favor of the Firmicutes population but not the Bacteroidetes population. No difference was observed in total bacterial counts among treatments. MOS promoted the growth of Lactobacillus spp. and Bifidobacterium spp. in the cecum and increased villus height and goblet cell numbers in the ileum and jejunum. These results provide a deeper insight into the microbial ecological changes after supplementation of MOS prebiotic in poultry diets.

The European ban on antibiotic growth promoters in animal feed: From challenges to opportunities

The European ban on antibiotic growth promoters in animal feed: From challenges to opportunities

Arsenic uptake by two vegetables grown in two soils amended with As-bearing animal manures

Organoarsenicals are widely used as growth promoters in animal feed, resulting in unabsorbed arsenic (As) left in animal manures. A pot experiment was conducted to investigate the growth and As uptake of amaranth ( Amaranthus tricolor Linn, a crop with an axial root system) and water spinach ( Ipomoea aquatica Forsk, a crop with a fibrous root system) grown in a paddy soil (PS) and a lateritic red soil (LRS) amended with 2% and 4% (w/w) As-bearing chicken manure and pig manure, respectively. Soils without any fertilizers were the controls. The biomass, As contents and total As uptake of the shoots, As transfer factors (TFs) from roots to shoots and the root/shoot (R/S) ratios of water spinach were significantly higher than those of amaranth ( p < 0.0015). The biomass, total As uptake and R/S ratios showed significant difference for soil types ( p < 0.0031). Manure amendments increased the biomass of both vegetables, reduced the As contents in amaranth but increased those in water spinach. The As contents were negatively correlated with the biomass in amaranth, but positive correlation was observed for water spinach. The total As uptake by amaranth was decreased in PS and insignificantly affected in LRS by manure application, but that by water spinach was significantly increased in both soils. We suggest that the higher As uptake by water spinach might be related to its root structure and R/S ratio. Heavy application of As-bearing animal manures should be avoided in water spinach.

Chromatographic analysis of banned antibacterial growth promoters in animal feed

The issue of antimicrobial use in animals used as food is of global concern. Antimicrobials are used in animal agriculture to improve health and welfare of animals, meat quality, the economic efficiency of growth and production and public health by decreasing shedding of zoonotic pathogens. However, large quantities are often used without professional supervision. The growth-promotant (now reclassified as zootechnical feed additives) effect of low levels of antibiotics in animal feeds was first described in the late 1940s. Already in 1969 the Swann Committee recommended that use of antibiotics as a supplement in animal feedstuff should be restricted to those with little or no application as therapeutic agents for humans and animals, which would not impair the efficacy of therapeutic antibiotics through the development of resistant strains of organisms. Antimicrobials like avoparcin, ardacin, zinc bacitracin, virginiamycin, tylosin, spriramycin, carbadox and olaquindox were withdrawn within the period 1997-1999. Four others (monensin sodium, salinomycin sodium, avilamycin and flavophospholipol) were still permitted for use as growth promoters in animal feed to animals marketed in the European Union (EU). Since January 2006, they have been banned as well. This review focuses on the analytical methods developed to be an effective tool for monitoring compliance with the ban.

Banned antibacterial growth promoters in animal feed: Collaborative trial on the liquid chromatography–tandem mass spectrometry method developed in the feedstuffs-radius project

A chemical confirmation method for the identification and quantification of five banned antibacterial growth promoters (AGPs) in animal feed was developed and in-house validated as part of the European Feedstuffs-RADIUS project [1]. To complete the validation process a collaborative trial was performed by eleven laboratories within the European Union (EU) using the developed method. Laboratories were supplied with six animal feed samples. None of the participants reported any false non-compliant results on these samples. Neither where there any false compliant results for four out of five compounds. These data proved the procedure to be robust and an excellent means of controlling misuse of the banned antibacterial growth promoters. During a small feed survey, a selection ( n = 614) of animal feed samples were screened with a multi-antibiotic ELISA method [2] that was developed in the same EU project and non-compliant samples were submitted to liquid chromatography-tandem mass spectrometry (LC–MS/MS) confirmation. The results from this confirmatory analysis indicated that the LC–MS/MS method will be a valuable tool in helping to determine the origin of the detected antibacterial compounds and that animals are still receiving tylosin in concentrations that are in the same range as the now banned AGP concentrations.

Detection of banned antibacterial growth promoters in animal feed by liquid chromatography–tandem mass spectrometry: optimisation of the extraction solvent by experimental design

Because of the risk that residues of antibacterial growth promoters in edible tissues could lead to allergic reactions and development of resistant strains of bacteria in humans, the European Commission decided to ban bacitracin, olaquindox, spiramycin, tylosin and virginiamycin as feed additives. To control the compliance of this ban, a single multi-analyte liquid chromatography–tandem mass spectrometry method was developed in 2003. Starting from this method, we further tried to optimise the response with the aid of experimental design. Using a central composite design, we searched for the optimal extraction solvent for each of the five components separately. As expected, this optimal composition was different for each of these antibacterial growth promoters. Two groups of compounds could be distinguished. The first group contained those compounds (spiramycin, tylosin and virginiamycin) that had the highest response (peak area) when the extraction solvent consisted of pure methanol (with or without the addition of formic acid). The second group contained the components (bacitracin and olaquindox) that preferred between 50 and 70% (v/v) methanol as extraction solvent. To find a compromise between these two groups, we created weighed utility functions and analysed these data with linear regression ( α < 0.05). The extraction solvent that gave the overall best response for the type of feed used during this experiment was very similar to the extraction solvent used during the validation of the multi-analyte method (70% (v/v) methanol and 2% (v/v) formic acid) [C. Van Poucke, K. De Keyser, A. Baltusnikiene, J.D.G. McEvoy, C. Van Peteghem, Anal. Chim. Acta 483 (2003) 99]. Finally, a recovery experiment was set up using different types of feed to identify if the outcome of this experiment was valid for all types of feedstuffs.