The time-course of broiler intestinal microbiota development after administration of cecal contents to incubating eggs

Background. The microbial populations that inhabit the gastrointestinal tract (GIT) are known to influence the health and growth performance of the host. Clean hatcheries and machine-based incubation practices in the commercial poultry industry can lead to the acquisition of aberrant microbiota in the GIT of chickens and a very high level of bird-to-bird variation. The lack of microbial profile flock uniformity presents challenges for harnessing and manipulating intestinal bacteria to better serve the host. Methods. Cecal contents from high or low performing chickens were used to inoculate the surface of eggs prior to hatching and then the initial gut colonisation was monitored and subsequent changes in gut microbiota composition were followed over time. Two different cecal treatment groups were compared to an untreated control group (n=32). Bacterial communities were characterised using high-throughput 16S rRNA gene sequencing techniques. Results. Cecal microbiota transfer via egg surface application did not transfer the performance profile of the donors to the recipient birds. One of the cecal inoculations provided a more uniform gut microbiota, but this was not reproduced in the second group with a different inoculum. Development of the intestinal community was reproducible in all three groups with some genera like Lactobacillus showing no change, others like Faecalibacterium increased in abundance slowly and steadily over time and others like Enterobacter were abundant only in the first days of life. Discussion. The cecal treatment reduced bird-to-bird variation in microbiota compo-sition. Although the high FCR performance of donor birds was not transferred with the cecal microbiota, all three groups, including the control, performed better than standard for the breed. The pattern of microbiota development was similar in all three flocks, indicating that the normal processes of microbiota acquisition largely swamped any effect of the cecal material applied to eggs. © 2017 Donaldson et al

Bacteria within the gastrointestinal tract microbiota correlated with improved growth and feed conversion: Challenges presented for the identification of performance enhancing probiotic bacteria

Identification of bacteria associated with desirable productivity outcomes in animals may offer a direct approach to the identification of probiotic bacteria for use in animal production. We performed three controlled chicken trials (n = 96) to investigate caecal microbiota differences between the best and poorest performing birds using four performance measures; feed conversion ratio (FCR), utilization of energy from the feed measured as apparent metabolisable energy, gain rate (GR), and amount of feed eaten (FE). The shifts in microbiota composition associated with the performance measures were very different between the three trials. Analysis of the caecal microbiota revealed that the high and low FCR birds had significant differences in the abundance of some bacteria as demonstrated by shifts in microbiota alpha and beta diversity. Trials 1 and 2 showed significant overall community shifts, however, the microbial changes driving the difference between good and poor performers were very different. Lachnospiraceae, Ruminococcaceae, and Erysipelotrichaceae families and genera Ruminococcus, Faecalibacterium and multiple lineages of genus Clostridium (from families Lachnospiraceae, Ruminococcaceae, and Erysipelotrichaceae) were highly abundant in good FCR birds in Trial 1. Different microbiota was associated with FCR in Trial 2; Catabacteriaceae and unknown Clostridiales family members were increased in good FCR and genera Clostridium (from family Clostridiaceae) and Lactobacillus were associated with poor FCR. Trial 3 had only mild microbiota differences associated with all four performance measures. Overall, the genus Lactobacillus was correlated with feed intake which resulted in poor FCR performance. The genus Faecalibacterium correlated with improved FCR, increased GR and reduced FE. There was overlap in phylotypes correlated with improved FCR and GR, while different microbial cohorts appeared to be correlated with FE. Even under controlled conditions different cohorts of birds developed distinctly different microbiotas. Within the different trial groups the abundance of certain bacterial groups correlated with productivity outcomes. However, with different underlying microbiotas there were different bacteria correlated with performance. The challenge will be to identify probiotic bacteria that can reliably deliver favorable outcomes from diverse microbiotas. © 2016 Stanley, Hughes, Geier and Moore

At-hatch administration of probiotic to chickens can introduce beneficial changes in gut microbiota

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Recent advances in culture-free microbiological techniques bring new understanding of the role of intestinal microbiota in heath and performance. Intestinal microbial communities in chickens assume a near-stable state within the week which leaves a very small window for permanent microbiota remodelling. It is the first colonisers that determine the fate of microbial community in humans and birds alike, and after the microbiota has matured there are very small odds for permanent modification as stable community resists change. In this study we inoculated broiler chicks immediately post hatch, with 3 species of Lactobacillus, identified by sequencing of 16S rRNA and pheS genes as L. ingluviei, L. agilis and L. reuteri. The strains were isolated from the gut of healthy chickens as reproducibly persistent Lactobacillus strains among multiple flocks. Birds inoculated with the probiotic mix reached significantly higher weight by 28 days of age. Although each strain was able to colonise when administered alone, administering the probiotic mix at-hatch resulted in colonisation by only L. ingluviei. High initial abundance of L. ingluviei was slowly reducing, however, the effects of at-hatch administration of the Lactobacillus mix on modifying microbiota development and structure remained persistent. There was a tendency of promotion of beneficial and reduction in pathogenic taxa in the probiotic administered group. © 2018 Baldwin et al

Nanoparticles in feed: Progress and prospects in poultry research

© 2016 Elsevier LtdThe global poultry industry has greatly expanded due to an increase in demand for chicken meat and eggs. Growth of the industry was followed by growth in research which resulted in improved growth rate, feed efficiency, health status, and reduced carriage of pathogens. However, major research focus was improvement in productivity. It is possible to manipulate feed formulations to improve the feed conversion ratio (FCR), which results in a lower feed requirement to achieve market weight. Feed additives, containing vitamins and minerals, are commonly added to typical diets to support rapid growth and favourable FCR. Nanoparticles can be added to feed and provide an excellent platform to incorporate in various compounds, such as vaccines and nutrient supplements, due to large surface area to volume ratio and high absorption in the body. Nanoparticles can enable direct transportation of compounds to targeted organs or systems while avoiding fast degradability often seen with antibiotics and can encourage multiple health benefits. Silver, currently the most common nanoparticle investigated for use in chicken feed, has been shown to improve the microbiota of chickens. However, the positive results are tempered by the finding that silver nanoparticles have relatively high toxicity in birds. The question therefore arises as to whether other nanoparticle forms of essential metals and natural compounds can be safely delivered to provide positive impacts on health and productivity without the toxic side effects that can be seen with silver nanoparticles. Here, we review the current state of nanoparticle use as a poultry feed supplement - the successes and pitfalls of nano-feed as reported by researchers across the world

The synthesis and characterisation of highly stable and reproducible selenium nanoparticles

This paper describes a simple and reproducible solution phase synthesis approach for selenium nanoparticles by reducing selenium tetrachloride in the presence of ascorbic acid. An optimization study with poly (sodium 4-styrenesulfonate) produced stable and spherical narrowly size distributed nanoparticles (46 nm) which are considered highly monodisperse. The presence of selenium nanoparticles was confirmed by UV-visible spectroscopy for surface plasmon resonance (262 nm), elemental dispersive spectroscopy (11 KeV and 12.5 KeV) and size ranges characterized by dynamic light scattering (PDI = 0.04, the ​size range of optimized nanoparticles = 35 nm to 75 nm), and visualized using scanning and transmission electron microscopy

Understanding the mechanisms of zinc bacitracin and avilamycin on animal production: Linking gut microbiota and growth performance in chickens

© 2017, Springer-Verlag Berlin Heidelberg. Unravelling the mechanisms of how antibiotics influence growth performance through changes in gut microbiota can lead to the identification of highly productive microbiota in animal production. Here we investigated the effect of zinc bacitracin and avilamycin on growth performance and caecal microbiota in chickens and analysed associations between individual bacteria and growth performance. Two trials were undertaken; each used 96 individually caged 15-day-old Cobb broilers. Trial 1 had a control group (n = 48) and a zinc bacitracin (50 ppm) treatment group (n = 48). Trial 2 had a control group (n = 48) and an avilamycin (15 ppm) treatment group (n = 48). Chicken growth performance was evaluated over a 10-day period, and caecal microbiota was characterised by sequencing of bacterial 16S rRNA gene amplicons. Avilamycin produced no effect on growth performance and exhibited little significant disturbance of the microbiota structure. However, zinc bacitracin reduced the feed conversion ratio (FCR) in treated birds, changed the composition and increased the diversity of their caecal microbiota by reducing dominant species. Avilamycin only produced minor reductions in the abundance of two microbial taxa, whereas zinc bacitracin produced relatively large shifts in a number of taxa, primarily Lactobacillus species. Also, a number of phylotypes closely related to lactobacilli species were positively or negatively correlated with FCR values, suggesting contrasting effects of Lactobacillus spp. on chicken growth performance. By harnessing such bacteria, it may be possible to develop high-productivity strategies in poultry that rely on the use of probiotics and less on in-feed antibiotics

Sorghum and wheat differentially affect caecal microbiota and associated performance characteristics of meat chickens

This study compared the effects of wheat-and sorghum-based diets on broiler chickens. The growth performance and caecal microbial community of chickens were measured and correlations between productivity and specific gut microbes were observed. Cobb broilers 15 days of age were individually caged and two dietary treatments were used, one with a wheat-based diet (n D 48) and another one with a sorghum-based diet (n D 48). Growth performance measurements were taken over a 10 day period and samples for microbiota analysis were taken at the end of that period. Caecal microbiota was characterised by sequencing of 16S bacterial rRNA gene amplicons. Overall, the results indicated that a sorghum-based diet produced higher apparent metabolisable energy (AME) and body-weight gain (BWG) values in chickens, compared to a wheatbased diet. Nevertheless, sorghum-fed birds had higher feed conversion ratio (FCR) values than wheat-fed birds, possibly because of some anti-nutritional factors in sorghum. Further analyses showed that caecal microbial community was significantly associated with AME values, but microbiota composition differed between dietary treatments. A number of bacteria were individually correlated with growth performance measurements. Numerous OTUs assigned to strains of Lactobacillus crispatus and Lachnospiraceae, which were prevalent in sorghum-fed chickens, were correlated with high AME and BWG values, respectively. Additionally, a number of OTUs assigned to Clostridiales that were prevalent in wheat-fed chickens were correlated with low FCR values. Overall, these results suggest that between-diet variations in growth performance were partly associated with changes in the caecal microbiota. © 2017 Crisol-Martínez et al

The gastrointestinal tract microbiota of the Japanese quail, Coturnix japonica

© 2016, Springer-Verlag Berlin Heidelberg.Microbiota in the gastrointestinal tract (GIT) plays an essential role in the health and well-being of the host. With the exception of chickens, this area has been poorly studied within birds. The avian GIT harbours unique microbial communities. Birds require rapid energy bursts to enable energy-intensive flying. The passage time of feed through the avian GIT is only 2–3.5 h, and thus requires the presence of microbiota that is extremely efficient in energy extraction. This investigation has used high-throughput 16S rRNA gene sequencing to explore the GIT microbiota of the flighted bird, the Japanese quail (Coturnix japonica). We are reporting, for the first time, the diversity of bacterial phylotypes inhabiting all major sections of the quail GIT including mouth, esophagus, crop, proventriculus, gizzard, duodenum, ileum, cecum, large intestine and feces. Nine phyla of bacteria were found in the quail GIT; however, their distribution varied significantly between GIT sections. Cecal microbiota was the most highly differentiated from all the other communities and showed highest richness at an OTU level but lowest richness at all other taxonomic levels being comprised of only 15 of total 57 families in the quail GIT. Differences were observed in the presence and absence of specific phylotypes between sexes in most sections

Selenium nanoparticles in poultry feed modify gut microbiota and increase abundance of Faecalibacterium prausnitzii

© 2017, Springer-Verlag GmbH Germany, part of Springer Nature. The poultry industry aims to improve productivity while maintaining the health and welfare of flocks. Pathogen control has been achieved through biosecurity, vaccinations and the use of antibiotics. However, the emergence of antibiotic resistance, in animal and human pathogens, has prompted researchers and chicken growers alike to seek alternative approaches. The use of new and emerging approaches to combat pathogen activity including nanotechnology, in particular, silver nanoparticles (NPs), has been found to not only eradicate pathogenic bacteria but also include issues of toxicity and bioaccumulation effects. Other novel metal nanoparticles could provide this pathogen reducing property with a more tailored and biocompatible nanomaterial for the model used, something our study represents. This study investigated the benefits of nanomaterial delivery mechanisms coupled with important health constituents using selenium as a biocompatible metal to minimise toxicity properties. Selenium NPs were compared to two common forms of bulk selenium macronutrients already used in the poultry industry. An intermediate concentration of selenium nanoparticles (0.9 mg/kg) demonstrated the best performance, improving the gut health by increasing the abundance of beneficial bacteria, such as Lactobacillus and Faecalibacterium, and short-chain fatty acids (SCFAs), in particular butyric acid. SCFAs are metabolites produced by the intestinal tract and are used as an energy source for colonic cells and other important bodily functions. Selenium nanoparticles had no significant effect on live weight gain or abundance of potentially pathogenic bacteria

Correlations between intestinal innate immune genes and cecal microbiota highlight potential for probiotic development for immune modulation in poultry

Immune function is influenced by the diversity and stability of the intestinal microbiota. A likely trade-off of immune function for growth has been demonstrated in heavier breeds of poultry that have been genetically selected for growth and feed efficiency traits. We investigated the expression of selected innate immune genes and genes encoding products involved in intestinal barrier function to determine whether function changes could be consistently linked to the phenotypic expression of feed conversion ratio (FCR), a common measure of performance within poultry broiler flocks. In addition, we compared individual cecal microbial composition with innate immune gene expression. Samples were utilised from two replicate trials termed P1E1 and P1E2. High (n = 12) and low (n = 12) performing birds were selected based on their individual FCR data from each replicate and combined for microbiota phylogenetic composition and immune gene expression analysis. Toll-like receptor 1 (TLR1La) and zonula occludens 1 (ZO1) were differentially expressed between high- and low-performing broilers. Several taxa were correlated with FCR; of these, unclassified YS2 and ZO1 were also positively correlated with each other. Interactions between taxa and differentially expressed innate immune genes between P1E1 and P1E2 were much greater compared to relationships between high- and low-performing birds. At the level of phylum, reciprocal correlations between tight junction proteins and Toll-like receptors with Bacteroidetes and Firmicutes were evident, as were correlations at the genus level. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature