Prebiotics and alternative poultry production

Alternative poultry production systems continue to expand as markets for organic and naturally produced poultry meat and egg products increase. However, these production systems represent challenges associated with variable environmental conditions and exposure to foodborne pathogens. Consequently, there is a need to introduce feed additives that can support bird health and performance. There are several candidate feed additives with potential applications in alternative poultry production systems. Prebiotic compounds selectively stimulate the growth of beneficial gastrointestinal microorganisms leading to improved health of the host and limiting the establishment of foodborne pathogens. The shift in the gastrointestinal microbiota and modulation of fermentation can inhibit the establishment of foodborne pathogens such as Campylobacter and Salmonella. Both current and potential applications of prebiotics in alternative poultry production systems will be discussed in this review. Different sources and types of prebiotics that could be developed for alternative poultry production will also be explored.

The changing microbiome of poultry meat; from farm to fridge

Chickens play host to a diverse community of microorganisms which constitute the microflora of the live bird. Factors such as diet, genetics and immune system activity affect this complex population within the bird, while external influences including weather and exposure to other animals alter the development of the microbiome. Bacteria from these settings including Campylobacter and Salmonella play an important role in the quality and safety of end-products from these birds. Further steps, including washing and chilling, within the production cycle aim to control the proliferation of these microbes as well as those which cause product spoilage. These steps impose specific selective pressures upon the microflora of the meat product. Within the next decade, it is forecast that poultry meat, particularly chicken will become the most consumed meat globally. However, as poultry meat is a frequently cited reservoir of zoonotic disease, understanding the development of its microflora is key to controlling the proliferation of important spoilage and pathogenic bacterial groups present on the bird. Whilst several excellent reviews exist detailing the microbiome of poultry during primary production, others focus on fate of important poultry pathogens such as Campylobacter and Salmonella spp. At farm and retail level, and yet others describe the evolution of spoilage microbes during spoilage. This review seeks to provide the poultry industry and research scientists unfamiliar with food technology process with a holistic overview of the key changes to the microflora of broiler chickens at each stage of the production and retail cycle.

Efficacy of In Ovo Delivered Prebiotics on Growth Performance, Meat Quality and Gut Health of Kuroiler Chickens in the Face of a Natural Coccidiosis Challenge

A study was carried out to assess the efficacy of prebiotic delivered in ovo on performance, carcass traits, meat quality and gut health in the face of a natural coccidiosis infection in Kuroiler chickens. On d 12 of incubation, 150 fertile eggs were divided into a prebiotic group injected with trans-galactooligosaccharides (Bi²tos) and a control group uninjected. Hatched chicks from each group were further divided: One group received antibiotic chick formula while the other was left untreated, giving rise to 4 groups-Control (C), Antibiotic (A), Bi²tos (B), and Bi²tos + Antibiotic (AB). Prebiotic improved growth performance at six weeks of age, AB birds were the heaviest at the end of the rearing period. The highest intestinal lesion scores and oocyst counts were recorded in C birds. B group had a slightly higher carcass weight and cuts yields tended to be higher in treated groups compared to C. Meat from B group displayed a higher amount of polyunsaturated fatty acids compared to C and a positively lower n-6/n-3 ratio compared to C and A. In conclusion, prebiotics with or without antibiotics reduced severity of intestinal lesions and oocyst excretion induced by natural infection with Eimeria, with positive effects on Kuroiler chicken productive traits.

Microstructure of the small intestine in broiler chickens fed a diet with probiotic or synbiotic supplementation

The aim of the study was to determine the effect of dietary supplementation of a probiotic and a synbiotic on the morphometric parameters of the small intestine of broiler chickens. The experiment was conducted on three hundred sixty, one-day-old female Ross 308 chicks, which were randomly selected from 20,000 birds and divided into three treatment groups (n = 120) with ten replicates per treatment. The control group (C) was fed a commercial diet, the probiotic group (PRO) was fed the same diet with an added 1% of the probiotic Lavipan® (Lactococcus lactis, Carnobacterium divergens, Lactobacillus casei, Lactobacillus plantarum and Saccharomyces cerevisiae), and the synbiotic group (SYN) was fed the commercial diet with an added synbiotic: 0.8% of the prebiotic RFO (extracted from lupin seeds) and 1% Lavipan®. According to the manufacturer's data, apart from the typical probiotic action,microorganisms contained in the preparation release anti-bacterial substances (hydrogen peroxide and bacteriocins) and, therefore, are antagonistic towards pathogenic bacteria present in the gut of animals. Supplementation took place in the first seven days of rearing, and all birds had ad libitum access to water and feed during the 42 days of the experiment. On the last day, all birds were slaughtered and samples from three segments of the small intestine were taken. Villi area, height, width and crypt depth ratios were read using Multiscan software. Synbiotic supplementation increased the BWG of broilers from first to tenth day of rearing, compared to the control group. The PRO group had improved villi morphometric parameters of the duodenum. In the jejunum and ileum, both bioactive substances improved villus width and villus surface area. Crypts were deeper in the small intestine of birds supplemented with bioactive substances, which allows greater renewal of the villi. As expected, the intestinal morphometric parameters of broiler chickens benefited from bioactive substance supplementation.

Applications of Microbiome Analyses in Alternative Poultry Broiler Production Systems

While most of the focus on poultry microbiome research has been directed toward conventional poultry production, there is increasing interest in characterizing microbial populations originating from alternative or non-conventional poultry production. This is in part due to the growing general popularity in locally produced foods and more specifically the attractiveness of free-range or pasture raised poultry. Most of the focus of microbiome characterization in pasture flock birds has been on live bird production, primarily on the gastrointestinal tract. Interest in environmental impacts on production responses and management strategies have been key factors for comparative microbiome studies. This has important ramifications since these birds are not only raised under different conditions, but the grower cycle can be longer and in some cases slower growing breeds used. The impact of different feed additives is also of interest with some microbiome-based studies having examined the effect of feeding these additives to birds grown under pasture flock conditions. In the future, microbiome research approaches offer unique opportunities to develop better live bird management strategies and design optimal feed additive approaches for pasture flock poultry production systems.

Pasture flock chicken cecal microbiome responses to prebiotics and plum fiber feed amendments

When prebiotics and other fermentation substrates are delivered to animals as feed supplements, the typical goal is to improve weight gain and feed conversion. In this work, we examined pasture flock chicken cecal contents using next generation sequencing (NGS) to identify and understand the composition of the microbiome when prebiotics and fermentation substrates were supplemented. We generated 16S rRNA sequencing data for 120 separate cecal samples from groups of chickens receiving one of 3 prebiotics or fiber feed additives. The data indicated that respective feed additives enrich for specific bacterial community members and modulate the diversity of the microbiome. We applied synthetic learning in microbial ecology (SLiME) analysis to interpret 16S rRNA microbial community data and identify specific bacterial operational taxonomic units (OTU) that are predictive of the particular feed additives used in these experiments. The results suggest that feed can influence microbiome composition in a predictable way, and thus diet may have indirect effects on weight gain and feed conversion through the microbiome.

Overview of Prebiotics and Probiotics: Focus on Performance, Gut Health and Immunity – A Review

Due to the threat and emergence of bacterial resistance against antibiotics, the use of in-feed antibiotics at therapeutic and subtherapeutic levels has been limited. Complete withdrawal of antibiotics as growth promoters (AGP) has led to poor gut health signs in chickens that include conditions like wet litter, intestinal bacteria overgrowth, poor growth performance, malabsorption and various diseases. Two of the most common alternatives to AGP are prebiotics and probiotics. Both prebiotics and probiotics have become the potential feed additives that improve the gut health, immune system and microbiota by various mechanisms of action, and enhance growth performance of chickens. The review discusses the modes of action like antibacterial, competitive exclusion (CE), and immunomodulatory properties of prebiotics and probiotics, particularly in poultry. In ovo feeding of prebiotics and probiotics with promising effect on growth performance and reduction of pathogens like Salmonella is also discussed in this review. However, it is necessary to conduct more research with prebiotics and probiotics as well as other feed additives to understand the detailed mechanisms of action and identify better alternatives for poultry production and health.

In ovo validation model to assess the efficacy of commercial prebiotics on broiler performance and oxidative stability of meat

The purpose of this study was to examine the effect of in ovo injection of 2 different prebiotics, DiNovo (DN; Laminaria spp., extract containing laminarin and fucoidan) and Bi2tos (BI; non-digestive trans-galactooligosaccharides from milk lactose digested with Bifidobacterium bifidum NCIMB 41171), on growth, slaughter traits, intramuscular fat percentage (IF) and muscle fiber diameter, and lipid oxidation of meat in chickens reared under commercial conditions, following an in ovo trial protocol. On d 12 of embryonic incubation, 350,560 Ross 308 eggs were randomly divided into 3 experimental groups and automatically injected in ovo with: physiological saline (control group), BI at dose of 3.5 mg/embryo and DN at dose of 0.88 mg/embryo. Hatched chicks (males and females) were allocated dependent on treatment group into 3 poultry houses on each farm (3 farms in total) with a stocking density of 21.2 to 21.5 chicks/m2 At 42 d of age, 14 randomly chosen birds (7 males and 7 females), per each treatment from each farm, were individually weighed and slaughtered. The results showed no significant differences of final number of chickens/chicken house, mortality, BW per treatment, stocking density (kg/m2), feed intake, feed conversion rate (FCR), and European Broiler Index among 3 experimental groups. Treatments with BI and DN were associated with slight increases (P > 0.05) in average BW and a minor improvement (P > 0.05) of FCR in BI group. Slaughtered chickens from DN and BI treated groups had significantly increase of BW, carcass weight, carcass yield, and breast muscle weight compared with the control group. IF and muscle fiber diameter were similar among groups. Males had significantly higher slaughter traits compared to females, except for breast muscle yield. The prebiotic treatments led to a higher lipid oxidation in meat, even if the detected TBA reactive substances were below the critical value recognized for meat acceptability. In conclusion, in ovo administration of prebiotics was associated with improvements in a number of parameters of relevance to commercial poultry production.

Microbial Populations in Naked Neck Chicken Ceca Raised on Pasture Flock Fed with Commercial Yeast Cell Wall Prebiotics via an Illumina MiSeq Platform

Prebiotics are non-digestible carbohydrate dietary supplements that selectively stimulate the growth of one or more beneficial bacteria in the gastrointestinal tract of the host. These bacteria can inhibit colonization of pathogenic bacteria by producing antimicrobial substances such as short chain fatty acids (SCFAs) and competing for niches with pathogens within the gut. Pasture flock chickens are generally raised outdoors with fresh grass, sunlight and air, which represents different environmental growth conditions compared to conventionally raised chickens. The purpose of this study was to evaluate the difference in microbial populations from naked neck chicken ceca fed with commercial prebiotics derived from brewer’s yeast cell wall via an Illumina MiSeq platform. A total of 147 day-of-hatch naked neck chickens were distributed into 3 groups consisted of 1) C: control (no prebiotic), 2) T1: Biolex^® MB40 with 0.2%, and 3) T2: Leiber^® ExCel with 0.2%, consistently supplemented prebiotics during the experimental period. At 8 weeks, a total of 15 birds from each group were randomly selected and ceca removed for DNA extraction. The Illumina Miseq platform based on V4 region of 16S rRNA gene was applied for microbiome analysis. Both treatments exhibited limited impact on the microbial populations at the phylum level, with no significant differences in the OTU number of Bacteroidetes among groups and an increase of Proteobacteria OTUs for the T1 (Biolex^® MB40) group. In addition there was a significant increase of genus Faecalibacterium OTU, phylum Firmicutes. According to the development of next generation sequencing (NGS), microbiome analysis based on 16S rRNA gene proved to be informative on the prebiotic impact on poultry gut microbiota in pasture-raised naked neck birds.

Yerba mate enhances probiotic bacteria growth in vitro but as a feed additive does not reduce Salmonella Enteritidis colonization in vivo

Yerba mate (Ilex paraguariensis) is a tea known to have beneficial effects on human health and antimicrobial activity against some foodborne pathogens. Thus, the application of yerba mate as a feed additive for broiler chickens to reduce Salmonella colonization was evaluated. The first in vitro evaluation was conducted by suspending Salmonella Enteritidis and lactic acid bacteria (LAB) in yerba mate extract. The in vivo evaluations were conducted using preventative and horizontal transmission experiments. In all experiments, day-of-hatch chicks were treated with one of the following 1) no treatment (control); 2) ground yerba mate in feed; 3) probiotic treatment (Lactobacillus acidophilus and Pediococcus; 9:1 administered once on day of hatch by gavage); or 4) both yerba mate and probiotic treatments. At d 3, all chicks were challenged with Salmonella Enteritidis (preventative experiment) or 5 of 20 chicks (horizontal transmission experiment). At d 10, all birds were euthanized, weighed, and cecal contents enumerated for Salmonella. For the in vitro evaluation, antimicrobial activity was observed against Salmonella and the same treatment enhanced growth of LAB. For in vivo evaluations, none of the yerba mate treatments significantly reduced Salmonella Enteritidis colonization, whereas the probiotic treatment significantly reduced Salmonella colonization in the horizontal transmission experiment. Yerba mate decreased chicken BW and decreased the performance of the probiotic treatment when used in combination. In conclusion, yerba mate had antimicrobial activity against foodborne pathogens and enhanced the growth of LAB in vitro, but in vivo yerba mate did not decrease Salmonella Enteritidis colonization.