Observations of microtrash ingestion in Cape Vultures in the Eastern Cape,South Africa

Ingestion of man-made items by birds can reduce stomach volume and block the digestive track. In southern Africa, microtrash within the regurgitation of Cape Vulture nestlings was last documented in 1983. We present evidence of nestling microtrash ingestion after a 30-year gap. Vulture nestlings were captured at a breeding colony in the Eastern Cape, South Africa. One nestling regurgitated three microtrash fragments. Two pieces of microtrash were collected from the nest of another nestling. Neither nestling appeared to have skeletal deformities or feather stress bars. Our results highlight the persistence of microtrash ingestion by Cape Vulture nestlings, which could impact the species negatively.     

The use of inulin in poultry feeding: a review

Since the European Union enforced the ban on antibiotic growth promoters in 2006, the research has been focused on natural feed additives which would have a proven positive impact on both production and animal health. Inulin is both the most commonly used and the most effective probiotic additive. The mechanism of inulin interactions with the avian body is complex, multidirectional and not fully understood. Despite a number of unresolved issues, many authors have demonstrated the positive impact of inulin on the host organism. Dietary supplementation of poultry feeding with inulin contributes to the modulation of intestinal microbiota through favouring a quick proliferation of beneficial Bifidobacterium and Lactobacillus strains and inhibiting the growth of pathogenic microbes. There are indications that inulin‐provoked changes in the host gut microbiota in poultry may alter the structure and histomorphology of the intestinal mucosa and improve its absorption capacity in poultry. It has also been demonstrated that inulin may affect the immune system and the systemic metabolism of minerals and lipids. The reports on inulin effects on the body and performance of poultry are often contradictory, as the effectiveness of this prebiotic is strongly dependent on the type and dose used, and the duration of its administration.     

昆虫肠道微生物功能及家蚕肠道微生物研究进展

昆虫肠道是一种特殊的微生物生长环境 ,肠道有益微生物生长会给宿主带来各种利好 ,在营养、防护方面对宿主产生积极影响.和哺乳动物相比 ,大部分昆虫肠道微生物种类较少 ,但一些昆虫肠道会寄生大量的特定的微生物.昆虫消化道形态、理化环境差异极大 ,这些因素都会影响肠道微生物种群结构.蚕桑研究人员对不同食物、饲养环境及逆境下家蚕肠道微生物也有研究 ,并在肠道微生物营养补充、抗病防护功能方面做了有益探索 ,表明有益微生物在提高食物转化效率和病害防控方面具有应用潜力.     

Fermentation characteristics of resistant starch,arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review

Dietary fibers (DF) contain an abundant amount of energy, although the mammalian genome does not encode most of the enzymes required to degrade them. However, a mutual dependence is developed between the host and symbiotic microbes, which has the potential to extract the energy present in these DF. Dietary fibers escape digestion in the foregut and are fermented in the hindgut, producing short-chain fatty acids (SCFA) that alter the microbial ecology in the gastrointestinal tract (GIT) of pigs. Most of the carbohydrates are fermented in the proximal part, allowing protein fermentation in the distal part, resulting in colonic diseases. The structures of resistant starch (RS), arabinoxylan (AX), and β-glucan (βG) are complex; hence, makes their way into the hindgut where these are fermented and provide energy substrates for the colonic epithelial cells. Different microbes have different preferences of binding to different substrates. The RS, AX and βG act as a unique substrate for the microbes and modify the relative composition of the gut microbial community. The granule dimension and surface area of each substrate are different, which influences the penetration capacity of microbes. Arabinose and xylan are 2 different hemicelluloses, but arabinose is substituted on the xylan backbone and occurs in the form of AX. Fermentation of xylan produces butyrate primarily in the small intestine, whereas arabinose produces butyrate in the large intestine. Types of RS and forms of βG also exert beneficial effects by producing different metabolites and modulating the intestinal microbiota. Therefore, it is important to have information of different types of RS, AX and βG and their roles in microbial modulation to get the optimum benefits of fiber fermentation in the gut. This review provides relevant information on the similarities and differences that exist in the way RS, AX, and βG are fermented, and their positive and negative effects on SCFA production and gut microbial ecology of pigs. These insights will help nutritionists to develop dietary strategies that can modulate specific SCFA production and promote beneficial microbiota in the GIT of swine.     

益生菌在恢复家兔肠道菌群平衡和解决腹泻中的作用

益生菌是一类有益于宿主健康的活性微生物,可以通过调节家兔肠道菌群的平衡和增强肠道屏障功能来发挥作用,能够抑制有害菌的生长,提高消化道内营养物质的吸收利用,增强免疫系统的功能,从而维持肠道健康。本文从益生菌对家兔肠道菌群的影响,益生菌治疗机制的探索等方面探讨益生菌在恢复家兔肠道菌群平衡和解决腹泻中的作用,分析了当前研究的局限性和未来研究方向,有助于推动益生菌在家兔腹泻治疗中的临床应用,为家兔肠道健康提供更全面的保障。     

Microbiota-gut-brain axis and nutritional strategy under heat stress

Heat stress is a very universal stress event in recent years. Various lines of evidence in the past literatures indicate that gut microbiota composition is susceptible to variable temperature. A varied microbiota is necessary for optimal regulation of host signaling pathways and disrupting microbiota-host homeostasis that induces disease pathology. The microbiota–gut–brain axis involves an interactive mode of communication between the microbes colonizing the gut and brain function. This review summarizes the effects of heat stress on intestinal function and microbiota–gut–brain axis. Heat stress negatively affects intestinal immunity and barrier functions. Microbiota-gut-brain axis is involved in the homeostasis of the gut microbiota, at the same time, heat stress affects the metabolites of microbiota which could alter the function of microbiota–gut–brain axis. We aim to bridge the evidence that the microbiota is adapted to survive and thrive in an extreme environment. Additionally, nutritional strategies for alleviating intestinal heat stress are introduced.     

Do swallows (Hirundo daurica) use the visual cue of hatchling down‐feathers to discriminate parasite alien nestlings?

Egg recognition is a variable but common anti‐parasitism defense among different species of birds with brood parasites. In contrast, nestling recognition is rare. Very few studies have found nestling recognition in brood parasite hosts and determined the rejection mechanism behind this behavior. Hosts may use the number of hatchling down‐feathers to reject parasite nestlings. We tested whether hatchling down‐feathers is a visual cue for the red‐rumped swallow, a host that can recognize and reject parasite nestlings. Our results indicated that red‐rumped swallows do not recognize foreign nestlings based on hatchling down‐feathers. The closed nest structure and hatchling morph may explain the absence of such a mechanism. None of the rejection mechanisms found in previous studies could explain the nestling recognition in swallows. Olfactory cues, tactile cues, or other visual cues, except for single nestling or hatchling down‐feathers, may provide nestling recognition in red‐rumped swallows. More study is needed to evaluate these possibilities.     

Piglet gut microbial shifts early in life:causes and effects

The gut microbiome has long been known to play fundamentally important roles in the animal health and the well-being of its host. As such, the establishment and maintenance of a beneficial gut microbiota early in life is crucial in pigs, since early gut colonizers are pivotal in the establishment of permanent microbial community structures affecting the health and growth performance of pigs later in life. Emphasizing this importance of early gut colonizers, it is critical to understand the factors impacting the establishment of the piglet gut microbiome at weaning. Factors include, among others, diet, in-feed antibiotics, probiotics and prebiotic administration. The impact of these factors on establishment of the gut microbiome of piglets at weaning includes effects on piglet gut microbial diversity, structure, and succession. In this review, we thoroughly reviewed the most recent findings on the piglet gut microbiome shifts as influenced by weaning, and how these microbiome changes brought about by various factors that have been shown to affect the development of microbiota in piglets. This review will provide a general overview of recent studies that can help to facilitate the design of new strategies to modulate the gut microbiome in order to enhance gastrointestinal health, growth performance and well-being of piglets.     

保育和育肥猪舍气溶胶微生物组成和四环素类抗性基因丰度研究

本研究旨在比较保育舍和育肥舍气溶胶微生物组成和四环素类抗性基因丰度的差异。采集8个保育舍和8个育肥舍的空气样品,用RT-qPCR方法检测特定微生物类群的相对丰度和四环素类抗性基因的绝对丰度。结果表明:与保育舍相比,育肥舍气溶胶微生物组中厚壁菌门、乳酸杆菌属、罗伊氏乳杆菌和约氏乳杆菌丰度显著提高(P<0.05),而拟杆菌门、梭菌属和普雷沃氏菌属丰度显著降低(P<0.05);育肥舍气溶胶中TetB、TetH、TetZ、TetO、TetQ和TetW的拷贝数显著低于保育舍(P<0.05);主成分分析表明,保育舍和育肥舍气溶胶可按照微生物丰度和四环素类抗性基因丰度进行聚类。由此可见,不同猪舍类型微生物组成存在明显差异,保育舍抗性基因丰度显著高于育肥舍。     

Informal Nutrition Symposium: Dynamics of the Digestive System Introduction

The PSA Informal Nutrition Symposium of 2005 provided excellent lessons in many areas related to the dynamics of the digestive system. The following are brief comments about the 5 outstanding presentations.Doug R. Korver explored the similarities between the avian and mammalian gut immune functions [1]. It is of critical interest that activation of the immune system will divert nutrients from production functions.Guillermo Tellez emphasized the importance of understanding the complexity of the gut microflora [2]. Such an understanding could lead to effective management of microorganisms in the digestive system.Charles L. Hofacre reviewed the importance of certain ionophores in playing a beneficial role in competitive exclusion of some bacteria in the digestive system and reducing the risk of necrotic enteritis [3].Edwin T. Moran, Jr., addressed the interrelationships between the anatomy, microbes, and fiber with special emphasis on the comparisons between the small and large intestines [4]. Different strategies are used by the digestive system to manage nutrient absorption at the intestinal surfaces. Such strategies were explored comprehensively.Elizabeth A. Koutsos elaborated on the value of using new technologies in studying the bacterial communities rather than focusing on individual microorganisms [5]. Discovering and pinpointing interactions among the intestinal ecology, anatomy, microflora, and nutrition will ultimately help reach a meaningful understanding.     

Performance and intestinal microbiota of chickens receiving probiotic in the feed and submitted to antibiotic therapy

The purpose of this study was to verify the ability of a probiotic in the feed to maintain the stability of the gut microbiota in chickens after antibiotic therapy and its association with growth performance. One thousand six hundred twenty 1‐day‐old Cobb male were housed in floor pens (36 pens, 45 birds/pen) and were fed corn‐/soya bean meal‐based diets supplemented with or without probiotic (Bacillus subtilis) during the entire rearing phase. From 21 to 24 days of age (three consecutive days), the chickens were submitted to antibiotic therapy via drinking water (bacitracin and neomycin) in order to mimic a field treatment and induce dysbiosis. Growth performance was monitored until 42 days of age. At 2, 4 and 6 days after antibiotic therapy, three chickens from each pen were euthanized and the contents of the small intestine and caeca were collected and pooled. The trial was conducted with four treatments and nine replicates in a 2 × 2 factorial arrangement for performance characteristics (with and without probiotic × with and without antibiotic therapy); for the intestinal microbiota, it was in a 2 × 2 × 3 factorial arrangement (with and without probiotic × with and without antibiotic therapy × 2, 4 and 6 days after the antibiotic therapy) with three replicates per treatment. Terminal restriction length polymorphism (T‐RFLP) analysis showed that the structure of gut bacterial community was shaped by the intestinal segment and by the time after the antibiotic therapy. The number of 16S rDNAs copies in caecum contents decreased with time after the therapeutic treatment. The antibiotic therapy and dietary probiotic supplementation decreased richness and diversity indexes in the caecal contents. The improved performance observed in birds supplemented with probiotic may be related to changes promoted by the feed additive in the structure of the intestinal bacterial communities and phylogenetic groups. Antibiotic therapy modified the bacterial structure, but did not cause loss of broiler performance.     

Comparative aspects of plant tannins on digestive physiology,nutrition and microbial community changes in sheep and goats: A review

Comparative aspects of plant tannins on digestive physiology, nutrition and microbial community in sheep and goats are discussed in the context of differences due to feed intake, digestibility, utilization of nutrients and microbial community. The purpose of this review was to present an overview of the potential benefits of tannin‐containing diets for sheep and goats and specie differences in their response to tannins. It is well established that moderate level of tannins in the diet (3%–4% tannins DM) can precipitate with soluble proteins and increase protein supply to the sheep, but comparative aspects of tannin‐containing diets in sheep and goats on animal performance, digestive physiology, rumen microbial changes and potential benefits to sustainable animal production by those compounds have received little attention. In addition, developing plant‐based tannin‐containing diets for control of rumen microbiota and rumen fermentation (e.g., methane gas) would be expected to have a greater impact on the ruminant health, productivity and emission of greenhouse gasses. The positive impacts of the plant tannin compounds mainly depend on their influence on the gut microbiome diversity and ability to generate fermentation end products (short‐chain fatty acids) that have diverse biological roles. Diets which contain optimal levels of tannins have potential benefits for sustainability of small ruminant production systems. However, there is a need for an improved understanding of the utilization of tannin‐containing forages to improve their management. This implies investigations of animal responses to tannin‐containing forages or browse species and, in particular, a better understanding of the interactions that can arise between sheep and goats on digestion, DMD, rumen fermentation and microbial community changes. This knowledge could help to improve current feeding systems in terms of efficiency of feed use and environmental impacts (reduce methane gas production) and thus contribute to the development of a sustainable sheep and goat production.     

益生菌在犊牛生产中的应用

益生菌具有无毒副作用、无耐药性和无残留等优点,不但受到研究者们的广泛关注,并且被大量应用于动物生产实践中,具有非常大的发展前景。幼龄阶段是肉牛生长非常重要的生理时期,此时犊牛的消化道微生物刚刚生长繁殖,而该期间有外源微生物进入到犊牛胃肠道中,就会在胃肠道中定植并形成特定的微生物区系。故在该时期的犊牛饲粮中添加益生菌,就会在犊牛的消化系统中建立有利于其生长的优势菌群,对犊牛的生长发育起到促进的作用。在简要介绍益生菌的定义及分类、犊牛的生长发育特点基础上,结合益生菌在反刍动物消化道中的作用机制的研究成果,就近年来益生菌在犊牛生产中的应用做一综述。     

Gut microbiota absence and transplantation affect growth and intestinal functions: An investigation in a germ-free pig model

This study was conducted to investigate host–microbiota interactions and explore the effects of maternal gut microbiota transplantation on the growth and intestinal functions of newborns in a germ-free (GF) pig model. Twelve hysterectomy-derived GF Bama piglets were reared in 6 sterile isolators. Among them, 6 were considered as the GF group, and the other 6 were orally inoculated with healthy sow fecal suspension as fecal microbiota transplanted (FMT) group. Another 6 piglets from natural birth were regarded as the conventional (CV) group. The GF and FMT groups were hand-fed with Co60-γ-irradiated sterile milk powder, while the CV group was reared by lactating Bama sows. All groups were fed for 21 days. Then, all piglets and then were switched to sterile feed for another 21 days. Results showed that the growth performance, nutrient digestibility, and concentrations of short-chain fatty acids in the GF group decreased (P < 0.05). Meanwhile, the serum urea nitrogen concentration and digesta pH values in the GF group increased compared with those in the FMT and CV groups (P < 0.05). Compared with the CV group, the GF group demonstrated upregulation in the mRNA expression levels of intestinal barrier function-related genes in the small intestine (P < 0.05). In addition, the mRNA abundances of intestinal development and absorption-related genes in the small intestine and colon were higher in the GF group than in the CV and FMT groups (P < 0.05). The FMT group exhibited greater growth performance, lipase activity, and nutrient digestibility (P < 0.05), higher mRNA expression levels of intestinal development and barrier-related genes in the small intestine (P < 0.05), and lower mRNA abundances of pro-inflammatory factor in the colon and jejunum (P < 0.05) than the CV group. In conclusion, the absence of gut microbes impaired the growth and nutrient digestibility, and healthy sow gut microbiota transplantation increased the growth and nutrient digestibility and improved the intestinal development and barrier function of newborn piglets, indicating the importance of intestinal microbes for intestinal development and functions.     

A comparison of the effects of antibiotics,probiotics, synbiotics and prebiotics on the performance and carcass characteristics of broilers

Routine use of the antibiotic flavomycin in broiler production may lead to resistance, and alternative growth promoters are used to enhance performance. Two hundred day-old male Ross 308 broiler chicks were allocated to five dietary supplements included from d 1–42: flavomycin, three possible alternatives, a probiotic, prebiotic and a synbiotic, as well as a control treatment. There were four replicate cages of 10 birds each in each treatment. Compared with the control and antibiotics treatments, the probiotic, prebiotic and synbiotic treatments increased (p?=?0.001) weight gain (64, 66, 73, 70 and 74 g/d, respectively). The synbiotic treatment reduced (p?=?0.004) the feed conversion ratio, compared with the control and antibiotic treatments (1.70, 1.84, 1.83, respectively). Compared with the control and antibiotic treatments, the birds fed the synbiotic treatment had greater relative gizzard (+47%) and spleen weights (+115%), and lighter kidneys (?47%). The birds fed the symbiotic treatment also had thinner walls of the caudal gut segments. The prebiotic had the most beneficial effect on cecal microbiota, stimulating aerobic and lactic acid producing bacteria and reducing Escherichia coli bacteria. Enterococci were increased in the antibiotic treatment. We conclude that there were significant performance and health benefits of using prebiotics, probiotics and synbiotics for broilers, rather than antibiotics.     

Swine gut microbiota and its interaction with host nutrient metabolism

Gut microbiota is generally recognized to play a crucial role in maintaining host health and metabolism. The correlation among gut microbiota, glycolipid metabolism, and metabolic diseases has been well reviewed in humans. However, the interplay between gut microbiota and host metabolism in swine remains incompletely understood. Given the limitation in conducting human experiments and the high similarity between swine and humans in terms of anatomy, physiology, polyphagy, habits, and metabolism and in terms of the composition of gut microbiota, there is a pressing need to summarize the knowledge gained regarding swine gut microbiota, its interplay with host metabolism, and the underlying mechanisms. This review aimed to outline the bidirectional regulation between gut microbiota and nutrient metabolism in swine and to emphasize the action mechanisms underlying the complex microbiome–host crosstalk via the gut microbiota–gut–brain axis. Moreover, it highlights the new advances in knowledge of the diurnal rhythmicity of gut microbiota. A better understanding of these aspects can not only shed light on healthy and efficient pork production but also promote our knowledge on the associations between gut microbiota and the microbiome–host crosstalk mechanism. More importantly, knowledge on microbiota, host health and metabolism facilitates the development of a precise intervention therapy targeting the gut microbiota.     

Insights into host-microbe interaction:What can we do for the swine industry?

Recent discoveries have underscored the cross-talk between intestinal microbes and their hosts. Notably, intestinal microbiota impacts the development, physiological function and social behavior of hosts. This influence usually revolves around the microbiota-gut-brain axis (MGBA). In this review, we firstly outline the impacts of the host on colonization of intestinal microorganisms, and then highlight the influence of intestinal microbiota on hosts focusing on short-chain fatty acid (SCFA) and tryptophan metabolite-mediated MGBA. We also discuss the intervention of intestinal microbial metabolism by dietary supplements, which may provide new strategies for improving the welfare and production of pigs. Overall, we summarize a state-of-the-art theory that gut microbiome affects brain functions via metabolites from dietary macronutrients.     

Dietary fiber and chicken microbiome interaction: Where will it lead to?

The last few decades have been marked by a rapid genetic improvement in chicken growth rates. The modern-day chicken is more efficient in converting feed into muscle mass than their predecessors. This enhanced efficiency emanates from better nutrient digestion, absorption, and metabolism. The gut has therefore become a research focus especially after the ban on the use of antibiotics as growth promoters (AGP) in poultry. In pursuance of better gut health in the post-AGP era, many different strategies are being continuously sought and tested. The gut is inhabited by more than 900 bacterial species along with fungi and archaea, and they play an important role to maintain a conducive milieu for the host. A beneficial shift in the microbial ecosystem of the chicken can be promoted by many dietary and non-dietary interventions, however, diet is ranked as one of the most important and potent regulators of gut microbiota composition. Therefore, the constituents of the diet warrant special attention in the modulation of the gut ecosystem. Among dietary constituents, fiber possesses a significant ability to modulate the microbiota. In this review, we will highlight the importance of fiber in poultry nutrition and will also discuss the effects of fiber on gut microbiota and its resultant ramifications on the liver and brain.     

Companion animals symposium: microbes and gastrointestinal health of dogs and cats

Recent molecular studies have revealed complex bacterial, fungal, archaeal, and viral communities in the gastrointestinal tract of dogs and cats. More than 10 bacterial phyla have been identified, with Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria, and Actinobacteria constituting more than 99% of all gut microbiota. Microbes act as a defending barrier against invading pathogens, aid in digestion, provide nutritional support for enterocytes, and play a crucial role in the development of the immune system. Of significance for gastrointestinal health is their ability to ferment dietary substrates into short-chain fatty acids, predominantly to acetate, propionate, and butyrate. However, microbes can have also a detrimental effect on host health. Specific pathogens (e.g., Salmonella, Campylobacter jejuni, and enterotoxigenic Clostridium perfringens) have been implicated in acute and chronic gastrointestinal disease. Compositional changes in the small intestinal microbiota, potentially leading to changes in intestinal permeability and digestive function, have been suggested in canine small intestinal dysbiosis or antibiotic-responsive diarrhea. There is mounting evidence that microbes play an important role in the pathogenesis of canine and feline inflammatory bowel disease (IBD). Current theories for the development of IBD favor a combination of environmental factors, the intestinal microbiota, and a genetic susceptibility of the host. Recent studies have revealed a genetic susceptibility for defective bacterial clearance in Boxer dogs with granulomatous colitis. Differential expression of pathogen recognition receptors (i.e., Toll-like receptors) were identified in dogs with chronic enteropathies. Similarly to humans, a microbial dysbiosis has been identified in feline and canine IBD. Commonly observed microbial changes are increased Proteobacteria (i.e., Escherichia coli) with concurrent decreases in Firmicutes, especially a reduced diversity in Clostridium clusters XIVa and IV (i.e., Lachnospiraceae, Ruminococcaceae, Faecalibacterium spp.). This would indicate that these bacterial groups, important short-chain fatty acid producers, may play an important role in promoting intestinal health.     

Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.