The response of gastrointestinal microbiota to avilamycin, butyrate, and plant extracts in early-weaned pigs

Synergetic response on herbal and probiotic applications: a review

Herbs and their by-products are important traditional medicines and food supplements; they provide numerous beneficial effects for animals. Consequently, probiotics are living cell organisms, nontoxic, and friendly microbes. Probiotics have numerous beneficial activities such as inhibition of pathogens, enhancement of the immune system, growth, disease resistance, improving water quality, reducing toxic effects, synthesis of vitamins, prevention of cancer, reduction of irritable bowel syndrome, and more positive responses in animals. Herbal and probiotic combinations have more active responses and produce new substances to enhance beneficial responses in animals. Herbal and probiotic mixture report is still limited applications for animals. However, the mechanisms by which they interact with the immune system and gut microbiota in animals are largely unclear. This review provides some information on the effect of herbal and probiotic blend on animals. This review discusses current research advancements to fulfill research gaps and promote effective and healthy animal production.

Effects of supplemental bacteriophage on the gut microbiota and nutrient digestibility of ileal-cannulated pigs

This study measured the potential changes of the microbiota in the gastrointestinal tract and energy and nutrient digestibility by supplemental bacteriophages in pigs. Twelve castrated male pigs (initial mean body weight = 29.5 ± 2.3 kg) were surgically cannulated using T-cannula. The animals were housed individually in pens equipped with a feeder and a nipple waterer. The pigs were allotted to 1 of 3 experimental diets in a quadruplicated 3 × 2 Latin square design with 3 experimental diets, 2 periods, and 12 pigs resulting in 8 replicates per diet. The 3 diets were a control mainly based on corn and soybean meal with no antibiotics or bacteriophages, a diet containing 0.1% antibiotics, and a diet containing 0.2% bacteriophages. On day 5 of the experimental period, feces were collected and on days 6 and 7, ileal digesta were collected. Genomic DNA for bacteria were extracted from the ileal digesta and feces and the V4 region of the 16S rRNA gene was amplified. The ileal and fecal digestibility of energy, dry matter, organic matter, crude protein, and fiber was unaffected by dietary antibiotics or bacteriophages. At the phylum level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Firmicutes (p = 0.059) and a lower proportion of Bacteroidetes (p = 0.099) in the ileal digesta samples compared with the control group with no difference between the antibiotic and bacteriophage groups. At the genus level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Lactobacillus (p = 0.062) and a lower proportion of Bacteroides (p = 0.074) and Streptococcus (p = 0.088) in the ileal digesta compared with the control group with no difference between the antibiotic and bacteriophage groups. In the feces, supplemental antibiotics or bacteriophages reduced the proportion of Bifidobacterium compared with the control group (p = 0.029) with no difference between the antibiotic and bacteriophage groups. Overall, supplemental antibiotics and bacteriophages showed positive effect on the microbiota of in the ileal digesta without largely affecting energy or nutrient digestibility, with no differences between the antibiotic and bacteriophage groups in growing pigs.

Swine Gastrointestinal Microbiota and the Effects of Dietary Amino Acids on Its Composition and Metabolism

Many researchers consider gut microbiota (trillions of microorganisms) an endogenous organ of its animal host, which confers a vast genetic diversity in providing the host with essential biological functions. Particularly, the gut microbiota regulates not only gut tissue structure but also gut health and gut functionality. This paper first summarized those common bacterial species (dominated by the Firmicutes, Bacteroidota, and Proteobacteria phyla) in swine gut and then briefly discussed their roles in swine nutrition and health, which include roles in nutrient metabolism, pathogen exclusion, and immunity modulation. Secondly, the current knowledge on how dietary nutrients and feed additives affect the gut bacterial composition and nutrient metabolism in pigs was discussed. Finally, how dietary amino acids affect the relative abundances and metabolism of bacteria in the swine gut was reviewed. Tryptophan supplementation promotes the growth of beneficial bacteria and suppresses pathogens, while arginine metabolism affects nitrogen recycling, impacting gut immune response and health. Glutamate and glutamine supplementations elevate the levels of beneficial bacteria and mitigate pathogenic ones. It was concluded that nutritional strategies to manipulate gut microbial ecosystems are useful measures to optimize gut health and gut functions. For example, providing pigs with nutrients that promote the growth of Lactobacillus and Bifidobacterium can lead to better gut health and growth performance, especially when dietary protein is limited. Further research to establish the mechanistic cause-and-effect relationships between amino acids and the dynamics of gut microbiota will allow swine producers to reap the greatest return on their feed investment.

Cutting-edge knowledge on the roles of phytobiotics and their proposed modes of action in swine

With the ban on antibiotics in the swine industry, the exploration of alternative options has highlighted phytobiotics as a promising substitute for antibiotic growth promoters, aiming to foster a more sustainable swine industry. Phytobiotics are non-nutritive natural bioactive components derived from plants that offer numerous health benefits. They exhibit antioxidative, antimicrobial, and anti-inflammatory effects. Phytobiotics can be utilized in various forms, including solid, dried, ground, or as extracts, either in crude or concentrated form. They are characterized by low residual levels, a lack of resistance development, and minimal adverse effects. These qualities make phytobiotics an attractive choice for enhancing health and productivity in swine, presenting them as a viable alternative to antibiotics. While there is a general understanding of the effects of phytobiotics, there is still a need for detailed information regarding their effectiveness and mechanisms of action in practical settings. Therefore, the purpose of this mini review was to summarize the current knowledge supporting the roles of phytobiotics and their proposed modes of action, with a specific focus on swine.

Nigella sativa as an antibiotic alternative to promote growth and enhance health of broilers challenged with Eimeria maxima and Clostridium perfringens

The poultry industry has significant coccidiosis and necrotic enteritis (NE) challenges, leading to high mortality and unacceptable growth without antibiotic treatment. This research explored supplementing Nigella sativa (black cumin) seed oil in poultry feed to mitigate coccidiosis and prevent or lessen NE in broilers. In vivo studies consisted of 384 and 320 Cobb 500 male broiler chicks distributed in a randomized complete block experimental design for trials 1 and 2, respectively. The first trial compared 3 concentrations (1, 2, and 5 mL/kg) of black cumin seed oil (BCSO), and trial 2 compared 2 concentrations (2 and 5 mL/kg) BCSO, with birds challenged with Eimeria maxima and Clostridium perfringens (Cp) strains Cp#6 and Cp#4, respectively. Broiler live performance, NE disease outcomes, and Cp populations were measured for both trials. A commercially available BCSO oil product, determined in a preliminary in vitro study to have the highest anti-Cp activity, was selected for in vivo studies. Gas chromatography-mass spectrometry analysis indicated the major bioactive compounds p-cymene, thymoquinone, carvacrol, and thymol were present in the BCSO. In trial 1 with strain Cp#6, BCSO concentrations of 2 and 5 mL/kg reduced NE lesion score and mortality rate to 1.6% compared with 7.8% for positive control, with no adverse impact on live performance. In trial 2 with strain Cp#4, BCSO reduced NE lesion scores and mortality rate to 35.9% compared with 51.6% for positive control and also improved weight gain when there was a Cp infection in broiler chickens. The current study compared NE in broilers challenged with 2 different Cp strains producing different levels of NE. Following Cp infection, both the population of vegetative cells and spores of Cp in cecal contents decreased for all treatments in trial 2. In conclusion, BCSO at concentrations of 2 and 5 mL/kg enhanced broiler live performance and alleviated NE and has potential as a natural, non-medication antimicrobial nutritional supplement for use as a feed additive in chickens.

Effects of a combination of lauric acid monoglyceride and cinnamaldehyde on growth performance, gut morphology, and gut microbiota of yellow-feathered broilers

A total of 480 one-day-old male yellow-feathered broilers were randomly divided into 4 groups with 6 replicates of 20 chicks per replicate. A basal diet was administered to the control group (CON), whereas CML350, CML500, and CML1000 groups were fed with basal diet supplemented with 350, 500, and 1,000 mg/kg of lauric acid monoglyceride and cinnamaldehyde complex, respectively. However, adding 500 mg/kg of lauric acid monoglyceride and cinnamaldehyde complex improved weight gain (P < 0.01), enhanced intestinal morphology, increased serum total protein and albumin content, and total antioxidant capacity (P < 0.01), and significantly increased the Chao1 and Ace indices (P < 0.01), indicating an increase in the richness of the gut microbiota. At the phylum level, CML500 group reduced the abundance of Fusobacteriota at 21 d and Proteobacteria at 42 d (P < 0.01). At the genus level, CML500 group increased the abundance of Faecalibacterium and Alistipes at 42 d (P < 0.01) and decreased the abundance of Escherichia-Shigella (P < 0.01). At the species level, CML500 group reduced the abundance of Escherichia coli at 42 d (P < 0.01) and increased the abundance of Alistipes_sp_CHKCI003 at 42 d (P < 0.01). According to these results, adding 500 mg/kg of lauric acid monoglyceride and cinnamaldehyde complex in feed can improve the growth performance, intestinal morphology, and gut microbiota of yellow-feathered broilers.

Review on Preventive Measures to Reduce Post-Weaning Diarrhoea in Piglets

In many countries, medical levels of zinc (typically as zinc oxide) are added to piglet diets in the first two weeks post-weaning to prevent the development of post-weaning diarrhoea (PWD). However, high levels of zinc constitute an environmental polluting agent, and may contribute to the development and/or maintenance of antimicrobial resistance (AMR) among bacteria. Consequently, the EU banned administering medical levels of zinc in pig diets as of June 2022. However, this may result in an increased use of antibiotic therapeutics to combat PWD and thereby an increased risk of further AMR development. The search for alternative measures against PWD with a minimum use of antibiotics and in the absence of medical levels of zinc has therefore been intensified over recent years, and feed-related measures, including feed ingredients, feed additives, and feeding strategies, are being intensively investigated. Furthermore, management strategies have been developed and are undoubtedly relevant; however, these will not be addressed in this review. Here, feed measures (and vaccines) are addressed, these being probiotics, prebiotics, synbiotics, postbiotics, proteobiotics, plants and plant extracts (in particular essential oils and tannins), macroalgae (particularly macroalgae-derived polysaccharides), dietary fibre, antimicrobial peptides, specific amino acids, dietary fatty acids, milk replacers, milk components, creep feed, vaccines, bacteriophages, and single-domain antibodies (nanobodies). The list covers measures with a rather long history and others that require significant development before their eventual use can be extended. To assess the potential of feed-related measures in combating PWD, the literature reviewed here has focused on studies reporting parameters of PWD (i.e., faeces score and/or faeces dry matter content during the first two weeks post-weaning). Although the impact on PWD (or related parameters) of the investigated measures may often be inconsistent, many studies do report positive effects. However, several studies have shown that control pigs do not suffer from diarrhoea, making it difficult to evaluate the biological and practical relevance of these improvements. From the reviewed literature, it is not possible to rank the efficacy of the various measures, and the efficacy most probably depends on a range of factors related to animal genetics and health status, additive doses used, composition of the feed, etc. We conclude that a combination of various measures is probably most recommendable in most situations. However, in this respect, it should be considered that combining strategies may lead to additive (e.g., synbiotics), synergistic (e.g., plant materials), or antagonistic (e.g., algae compounds) effects, requiring detailed knowledge on the modes of action in order to design effective strategies.

Effects of Dietary Carbohydrases on Fecal Microbiome Composition of Lactating Sows and Their Piglets

Corn-soybean meal diets are commonly used in the pork industry as a primary source of energy and protein. However, such a diet generally contains non-starch polysaccharides (NSPs) which present a challenge in finding ways to improve their availability and digestibility. Dietary multi-carbohydrases (MCs) have been proposed as an efficient approach to utilize NSPs, and can result in improved growth performance and host intestinal fitness. In this study, we evaluated the effects of MC in lactation diets on gut microbiota composition of lactating sows and their litters. The experimental design contained two dietary treatments, a diet based on corn-soybean meal (CON), and CON supplemented with 0.01% multigrain carbohydrases (MCs). Sow and piglet fecal samples were collected on days 7 and 28 after farrowing. Based on the results from 16S rRNA gene amplicon sequencing, MC led to changes in species diversity and altered the microbial compositions in lactating sows and their piglets. Specifically, the MC treatment induced an increase in the proportions of Lactobacillus in piglets. Clostridium and Spirochaetaceae showed a significantly reduced proportion in MC-treated sows at day 28. Our results support the beneficial effects of dietary carbohydrases and their link with improved production due to better host fitness outcomes and gut microbiota composition.

Effects of Sophorolipid on Growth Performance, Organ Characteristics, Lipid Digestion Markers, and Gut Functionality and Integrity in Broiler Chickens

Simple Summary

Availability of dietary fat and oil is important to broiler chicken due to their rapid growth rate. Therefore, we conducted an experiment with dietary sophorolipid, a glycolipid-type emulsifier, to investigate growth, lipid digestion markers and gut health during the growing period. Growth was accelerated by dietary sophorolipid supplementation through upregulation of lipid digestion and absorption markers. Additionally, dietary sophorolipid also increased the surface area of the gut and modulated microbial population and short-chain fatty acid concentration. Collectively, this study proposed that sophorolipid addition in feed could enhance chicken’s growth by increased intestinal absorption of dietary lipid and improved gut microenvironments.

Abstract

Dietary fat and oil could aid in reaching the high-energy requirements of fast-growing birds; however, these inclusions could lead to nutrient waste. This is because young birds have limited lipid digestion due to the low secretion of lipase and bile salt. Sophorolipid (SPL), a glycolipid emulsifier with lower toxicity and higher biodegradability, can upregulate fat utilization by increasing digestibility. Accordingly, a five-week-long experiment was conducted with 720 one-day-old chicks (Ross 308) to investigate the effects of dietary SPL on growth, organ characteristics, and gut health. The allotment was partitioned into four treatment groups according to their body weight with six replications (30 chick/pen). The three treatment diets comprised a basal diet with a formulation that met the Ross 308 standard and 5, 10, and 15 ppm SPL in the basal diet. During the experiment, the birds had free access to feed, and body weight and feed intake were measured at the end of each phase. Chickens were put down at the end of the growing and finishing phases, and jejunum and cecal samples were obtained to investigate organ characteristics and gut environments. The data were analyzed using the generalized linear model procedures of SAS 9.4, and all data were assessed for linear, quadratic, and cubic effects of dietary SPL-supplemented dosages. Body weight was significantly increased with 10 ppm of SPL supplementation in the grower phase without affecting feed efficiency. The relative weights of the intestine and the bursa of Fabricius were quadratically decreased by SPL supplementation with a lower population of Streptococcus and higher propionate and butyrate concentrations. Additionally, the dietary SPL supplementation groups showed a significantly increased villus/crypt ratio with higher intestinal expression levels of fatty acid translocase, diacylglycerol acyltransferase 2, and fatty acid transporter 4. Collectively, proper SPL supplementation in the chicken diet could improve growth performance by down-regulating immune modulation and up-regulating lipid digestion and absorption via modulation of gut microenvironments.

Black Pepper or Radish Seed Oils in a New Combination of Essential Oils Modulated Broiler Chickens’ Performance and Expression of Digestive Enzymes, Lipogenesis, Immunity, and Autophagy-Related Genes

Optimal combinations of essential oils (EOs) can enhance performance and maintain poultry productivity. The effects of EOs with black pepper oil (BPO) or radish seed oil (RSO) on performance and the expression of digestive enzymes, lipogenesis, immunity, and autophagy-related genes in broiler chickens were explored. Six dietary treatments for 300 one-day-old chicks were allocated as follows: controls were fed a basal diet, one group was fed an EO-supplemented diet (1.5 g/kg diet of parsley, mint, and carrot seed oils (1:1:1)), and other groups received Eos + BPO0.25, Eos + BPO0.5, Eos + RSO0.25, and Eos + RSO0.5 treatments, with a basal diet containing EOs plus BPO or RSO at the level of 0.25 or 0.5 g/kg, respectively. Supplementation with 0.5 g/kg of EOs plus BPO or RSO resulted in the most improved maximum BWG and FCR in broiler chickens. The lactobacilli population was increased in Eos + BPO0.5, followed by EOs + RSO0.5, unlike in the control. The highest expression of the CCK and PNLIP genes was identified in the Eos + BPO group. The FAS and ACC genes were upregulated, while the IgA and IL-10 genes were downregulated, with EOs plus RSO or BPO. The group that received Eos + BPO0.5, followed by Eos + RSO0.5, displayed patterns of higher expression for atg5, atg7, and atg12, with lower expression of mTOR. In summary, a new combination of EOs with 0.5 g/kg BPO had potential growth-promoting and immune-boosting effects in broiler chickens.

Effects of Dietary Supplementation with Protected Sodium Butyrate on Gut Microbiota in Growing-Finishing Pigs

Simple Summary

The addition of protected sodium butyrate to the diet of fattening pigs during the whole fattening period (≈90 days) at a dose of 3 kg per ton of feed, did not modify the overall richness of microbiota composition of the pigs at slaughter, but may have caused some significant changes in specific taxa that could be associated with better gut health parameters. In any case, these results should be taken with caution, as the role of a given taxon on the pig’s gut health is influenced by numerous variables such as age, diet, environment, treatments, other taxa present, infections, or even the physiological status of the animal.

Abstract

The study assessed changes in the gut microbiota of pigs after dietary supplementation with protected sodium butyrate (PSB) during the growing-fattening period (≈90 days). One gram of colon content from 18 pigs (9 from the treatment group -TG- and 9 from the control group -CG-) was collected. Bacterial DNA was extracted and 16S rRNA high-throughput amplicon sequencing used to assess microbiota changes between groups. The groups shared 75.4% of the 4697 operational taxonomic units identified. No differences in alpha diversity were found, but significant differences for some specific taxa were detected between groups. The low-represented phylum Deinococcus-Thermus, which is associated with the production of carotenoids with antioxidant, anti-apoptotic, and anti-inflammatory properties, was increased in the TG (p = 0.032). Prevotellaceae, Lachnospiraceae, Peptostreptococcaceae, Peptococcaceae, and Terrisporobacter were increased in the TG. Members of these families have the ability to ferment complex dietary polysaccharides and produce larger amounts of short chain fatty acids. Regarding species, only Clostridium butyricum was increased in the TG (p = 0.048). Clostridium butyricum is well-known as probiotic in humans, but it has also been associated with overall positive gut effects (increased villus height, improved body weight, reduction of diarrhea, etc.) in weanling pigs. Although the use of PSB did not modify the overall richness of microbiota composition of these slaughter pigs, it may have increased specific taxa associated with better gut health parameters.

Pathogen Challenge and Dietary Shift Alter Microbiota Composition and Activity in a Mucin-Associated in vitro Model of the Piglet Colon (MPigut-IVM) Simulating Weaning Transition

Enterotoxigenic Escherichia coli (ETEC) is the principal pathogen responsible for post-weaning diarrhea in newly weaned piglets. Expansion of ETEC at weaning is thought to be the consequence of various stress factors such as transient anorexia, dietary change or increase in intestinal inflammation and permeability, but the exact mechanisms remain to be elucidated. As the use of animal experiments raise more and more ethical concerns, we used a recently developed in vitro model of piglet colonic microbiome and mucobiome, the MPigut-IVM, to evaluate the effects of a simulated weaning transition and pathogen challenge at weaning. Our data suggested that the tested factors impacted the composition and functionality of the MPigut-IVM microbiota. The simulation of weaning transition led to an increase in relative abundance of the Prevotellaceae family which was further promoted by the presence of the ETEC strain. In contrast, several beneficial families such as Bacteroidiaceae or Ruminococcaceae and gut health related short chain fatty acids like butyrate or acetate were reduced upon simulated weaning. Moreover, the incubation of MPigut-IVM filtrated effluents with porcine intestinal cell cultures showed that ETEC challenge in the in vitro model led to an increased expression of pro-inflammatory genes by the porcine cells. This study provides insights about the etiology of a dysbiotic microbiota in post-weaning piglets.

Investigating the Effects of a Phytobiotics-Based Product on the Fecal Bacterial Microbiome of Weaned Pigs

The transition to a solid diet, as well as environmental and social stress, have a direct impact on swine gut physiology during weaning, affecting host gastrointestinal functions, as well as resident symbiotic microbial communities. While plant-derived bioactive products, such as phytobiotics, have shown great potential to mitigate these challenges, providing benefits such as antimicrobial, antioxidant, and anti-inflammatory activities, their mechanisms of action remain largely unexplored. To gain more insight, a 21 day trial is conducted to investigate the effects of LiveXtract, a commercial plant-based product, using fecal samples as a proxy for gut bacteria in weaned pigs. High-throughput sequencing of amplicons targeting the V1-V3 region of the 16S rRNA gene is used to determine bacterial composition at days 1 (pre-treatment), 4, 10, and 21 postweaning. Our results show that Lactobacillaceae and Peptostreptococcaceae are both higher in the supplemented group at D4 (p < 0.05), while Streptococcaceae are significantly lower in the treated group at D10 and D21. At D10, Erysipelotrichaceae are lower, and Veillonellaceae are higher in the treated samples than the control group (p < 0.05). Of the thirteen abundant Operational Taxonomic Units (OTUs) that have different representation between treated and control pigs (p < 0.05), six are predicted to be lactate producers (affiliation to Lactobacillus or Streptococcus), and one is predicted to be a lactate utilizer, based on its high identity to Megasphaera elsdenii. Together, these data suggest that phytobiotics may provide a favorable metabolic equilibrium between lactate production and utilization. Lactate is considered a critical microbial end product in gut environments, as it can inhibit pathogens or be metabolized to propionate for utilization by host cells.

The Applicability of Essential Oils in Different Stages of Production of Animal-Based Foods

Essential oils (EOs) have been used for centuries, and interest in these compounds has been revived in recent years. Due to their unique chemical composition as well as antimicrobial, immunostimulatory, anti-inflammatory and antioxidant properties, EOs are used in pharmacology, cosmetology and, increasingly, in animal breeding and rearing, and processing of animal raw materials. Essential oils have become a natural alternative to preservatives, taste enhancers and, most importantly, antibiotics, because the European Union banned the use of antibiotics in metaphylaxis in animal husbandry in 2006. In the animal production chain, EOs are used mainly as feed additives to improve feed palatability and increase feed intake, improve animal resistance and health status, and to prevent and treat diseases. Recent research indicates that EOs can also be applied to sanitize poultry houses, and they can be used as biopesticides in organic farming. Essential oils effectively preserve meat and milk and, consequently, improve the safety, hygiene and quality of animal-based foods. Novel technologies such as encapsulation may increase the bioavailability of EOs and their application in the production of food and feed additives.

Dose-response and functional role of whey permeate as a source of lactose and milk oligosaccharides on intestinal health and growth of nursery pigs

Two experiments were conducted to evaluate dose-response and supplemental effects of whey permeate on growth performance and intestinal health of nursery pigs. In experiment (exp.) 1, 1,080 pigs weaned at 6.24 kg body weight (BW) were allotted to five treatments (eight pens/treatment) with increasing levels of whey permeate in three phases (from 10% to 30%, 3% to 23%, and 0% to 9% for phase 1, 2, and 3, respectively) fed until 11 kg BW and then fed a common phase 4 diet (0% whey permeate) until 25 kg BW in a 48-d feeding trial. Feed intake and BW were measured at the end of each phase. In exp. 2, 1,200 nursery pigs at 7.50 kg BW were allotted to six treatments (10 pens/treatment) with increasing levels of whey permeate from 0% to 18.75% fed until 11 kg BW. Feed intake and BW were measured during 11 d. Six pigs per treatment (1 per pens) were euthanized to collect the jejunum to evaluate tumor necrosis factor-alpha, interleukin-8 (IL-8), transforming growth factor-beta 1, mucin 2, histomorphology, digestive enzyme activity, crypt cell proliferation rate, and jejunal mucosa-associated microbiota. Data were analyzed using contrasts in the MIXED procedure and a broken-line analysis using the NLIN procedure of SAS. In exp. 1, increasing whey permeate had a quadratic effect (P < 0.05) on feed efficiency (G:F; maximum: 1.35 at 18.3%) in phase 1. Increasing whey permeate linearly increased (P < 0.05) average daily gain (ADG; 292 to 327 g/d) and G:F (0.96 to 1.04) of pigs in phase 2. In exp. 2, increasing whey permeate linearly increased (P < 0.05) ADG (349 to 414 g/d) and G:F (0.78 to 0.85) and linearly increased (P < 0.05) crypt cell proliferation rate (27.8% to 37.0%). The breakpoint from a broken-line analysis was obtained at 13.6% whey permeate for maximal G:F. Increasing whey permeate tended to change IL-8 (quadratic, P = 0.052; maximum: 223 pg/mg at 10.9%), to decrease Firmicutes:Bacteroidetes (P = 0.073, 1.59 to 1.13), to increase (P = 0.089) Bifidobacteriaceae (0.73% to 1.11%), and to decrease Enterobacteriaceae (P = 0.091, 1.04% to 0.52%) and Streptococcaceae (P = 0.094, 1.50% to 0.71%) in the jejunal mucosa. In conclusion, dietary inclusion of whey permeate increased the growth of nursery pigs from 7 to 11 kg BW. Pigs grew most efficiently with 13.6% whey permeate. Improvement in growth performance is partly attributed to stimulating intestinal immune response and enterocyte proliferation with positive changes in jejunal mucosa-associated microbiota in nursery pigs.

A minimally invasive catheterization of the external jugular vein in suckling piglets using ultrasound guidance

There is a growing interest for minimally invasive surgical procedures to improve experimental animal welfare. Minimally invasive catheterization procedures in pigs have been already developed using Seldinger technique but reproducibility is low, especially in young pigs. A novel method for a minimally invasive catheterization of external jugular vein was evaluated in suckling piglets of 21 days of age. Growth performance and haptoglobin concentration in plasma were measured throughout a four-week study in a group of seven catheterized piglets and a group of seven non-catheterized piglets. Catheterization was performed using Seldinger technique under continuous ultrasound monitoring for vein detection and needle insertion. The surgical procedure was quick and showed a great reproducibility. All catheters remained functional during the first week after catheterization. Catheterization in piglets did not significantly affect body weight (BW) and feed intake during four weeks after the surgical intervention compared to non-catheterized piglets (P > 0.10). Haptoglobin concentration in plasma was greater in catheterized piglets compared with non-catheterized piglets, with a significant increase over two weeks after catheter insertion (P < 0.05), suggesting the development of a chronic inflammation in catheterized piglets. This method can be easily performed in piglets with minimal effect on growth and feeding behaviour. Transposition to heavier pigs should be considered.

Phenomenal Bombardment of Antibiotic in Poultry: Contemplating the Environmental Repercussions

Antibiotics have constantly been added at an unprecedented rate in order to enhance poultry meat production. Such antibiotics impose a negative impact on human health directly through meat and egg consumption. On the other hand, they also affect humans indirectly by affecting the normal key microbial processes in the agricultural environments, when used as poultry compost. For many years, farmers have been turning poultry litter into compost for agricultural use. Very few studies have addressed the fate of the unmetabolized antibiotic residues in poultry litter that could potentially affect microbial communities when used as poultry compost. We have also questioned the fate of residual antibiotic in poultry waste which may create possible negative environmental pressure on microbial communities that are involved in microbial mediated poultry litter composting processes. The incorporation of antibiotic degrading environmental isolates in poultry litter at the initial stage of composting in order to accelerate the process is addressed in this review as a future perspective.

Micro-encapsulated essential oils and organic acids combination improves intestinal barrier function, inflammatory responses and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli F4 (K88+)

This study evaluated the effects of micro-encapsulated (protected) organic acids (OA) and essential oils (EO) combination, P(OA + EO), and effects of a regular blend of free acids (FA) on the growth, immune responses, intestinal barrier and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4 (K88⁺). A total of 30 crossbred (Duroc × Landrace × Large White) weaned barrows (7.41 ± 0.06 kg, 28 d old) were assigned randomly to 5 treatments: 1) non-challenged positive control (PC), 2) ETEC F4 (K88⁺)-challenged negative control (NC), 3) NC + kitasamycin at 50 mg/kg + olaquindox at 100 mg/kg + free acidifier (FA) at 5 g/kg, 4) NC + kitasamycin at 50 mg/kg + olaquindox at 100 mg/kg + P(OA + EO) at 1 g/kg (P1), 5) NC + kitasamycin at 50 mg/kg + olaquindox at 100 mg/kg + P(OA + EO) at 2 g/kg (P2). Each dietary treatment had 6 replicates of one piglet each and the study lasted for 3 wk. On d 7, pigs in NC, FA, P1 and P2 were orally dosed with 10 mL of ETEC F4 (K88⁺) culture (1 × 10⁹ CFU/mL). From d 7 to 14 after the ETEC F4 (K88⁺) challenge, P1 increased gain-to-feed ratio (G:F) significantly (P < 0.05) compared with NC and FA groups. From d 14 to 21, P2 increased the average daily gain of pigs (P < 0.05) compared with NC and FA groups. Compared with NC, P2 reduced tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-10 concentrations (P < 0.05) in sera collected at 4 h later after ETEC F4 (K88⁺) challenge. On d 21, P1 increased occludin and zonula occludens-1 protein expression in ileum compared with NC (P < 0.05). After this 3-wk experiment, alpha diversity of gut microbiota was decreased by P2 compared with PC, and P1 increased the relative abundance of Lactobacillus in ileum, cecum and colon (P < 0.05). In conclusion, dietary P(OA + EO) additive at 2 g/kg combined with antibiotics could improve piglet performance and attenuate inflammation, and P(OA + EO) additive at 1 g/kg combined with antibiotics improved intestinal barrier and increased beneficial microbiota composition after an F4 (K88⁺) challenge.

Effect of Maternal Diet and Medium Chain Fatty Acids Supplementation for Piglets on Their Digestive Tract Development, Structure, and Chyme Acidity as Well as Performance and Health Status

Simple Summary

Weaning is the most critical period of piglet rearing. During this time, pigs have not yet fully developed their intestinal tract and immune system; therefore, they are an easy target for pathogenic microorganisms that cause gastrointestinal diseases. In the last decade, several nutritional factors were studied to prevent gastrointestinal disorders in piglets. The present study aimed to evaluate the effect of oils for sows during late pregnancy and lactation on offspring performance. In addition, the study determined the effect of caprylic acid or medium-chain triglyceride oil in piglets’ feed on their intestinal structure development, fatty acids content of chyme, productive performance, and health status. Summarizing, the study showed that coconut oil fed to pregnant and lactating sows can markedly reduce the mortality of piglets during the weaning period and that caprylic acid and medium-chain fatty acid oil can be a good feed supplement in weaned piglet feed. The nutritional factors tested in the present study could be used in the diet of sows and piglets to improve the health of piglets and thus the efficiency of pig production.

Abstract

The objective of the present study was to evaluate the effect of oils for sows during late pregnancy and lactation on offspring performance. In addition, the effect of caprylic acid (C8) or medium-chain triglyceride oil (MCT) in piglets’ feed on their gut development, performance, and health status was determined. The experiment was conducted on 24 sows allocated to two treatments: diet with rapeseed oil or with coconut oil. Newborn piglets were randomly allocated to three treatments: feed with no supplement or supplemented with 0.3% MCT or with 0.3% C8. The results showed that both oils had no effect on sow reproductive rates; however, fatty acid patterns of milk differed significantly and the number of lost piglets was lower in sow fed with coconut oil. Both caprylic and MCT oil significantly improved piglet performance and villus height. These additives did not change triacylglycerol content in blood, but C8 lowered total cholesterol and MCT increased IgG content. It can be concluded that coconut oil fed to pregnant and lactating sows can markedly reduce the mortality of piglets and that caprylic acid and medium-chain fatty acid oil can be a good supplement in weaned piglet feed.

Non-antibiotic Possibilities in Prevention and Treatment of Calf Diarrhoea

Due to increasing bacterial antibiotic resistance and the consumers' tendency to choose organic products, cattle farmers are interested in alternative methods of calf diarrhoea treatment. This is a major challenge for veterinarians. Few methods of non-antibiotic treatment that bring satisfactory results have been reported in the related literature so far. In this article, the authors compare different non-antibiotic methods of diarrhoea prevention and treatment in calves. Among the alternatives discussed are herbs, probiotics, prebiotics and synbiotics, lactoferrin, and bacteriophages. It was found that the best results could be achieved through the use of pro-, pre- and synbiotics. However, the authors would like to point out that with the expansion of knowledge about the practical use of broad-scale bacteriophages, they could be the best alternative to antibiotics.

Effects of Dietary Supplementation with Combination of Tributyrin and Essential Oil on Gut Health and Microbiota of Weaned Piglets

Simple Summary

The dietary inclusion of the combination of tributyrin with either oregano or methyl salicylate as a substitution to antibiotics improved intestinal morphological structure of weaned piglets and resulted in major changes in the profiles of intestine microbiota and metabolites, which exerted beneficial effects on intestinal health of piglets. Our study indicated that the combination of tributyrate with oregano or methyl salicylate could be used as an alternative feed additive to the antibiotics.

Abstract

The aim of this study was to determine the effects of dietary inclusion of the combination of tributyrin with oregano or methyl salicylate as a substitute to antibiotics on gut health and microbiota of piglets. A total of 48 weaned crossbred piglets (Duroc × Large White × Landrace, 8.79 ± 0.97 kg, 21 ± 1 d) were randomly allocated to four experimental groups and fed for 4 weeks: the basal diet (Con); the control plus antibiotics (AB); the control plus oregano and tributyrin (OT); and the control plus methyl salicylate and tributyrin (MT). Although a numerical improvement on feed intake, weight gain and feed conversion ratio was observed in the OT and MT as well as the AB group, the difference was not significant (p > 0.05). The OT and MT groups were larger in villus height in the duodenum compared to the Con (p < 0.05), and were larger in relative abundance of Firmicutes/Bacaeroides in the intestine compared to Con and AB groups (p < 0.01). The amount of major different metabolites was 6, 8 and 8 for the AB, OT and MT groups when compared to the Con, respectively. In conclusion, as a substitute for antibiotics the inclusion of the combination of tributyrin with either oregano or methyl salicylate to the diet of weaned piglets improved the intestinal morphological structure and altered intestinal microbiota and metabolites, which were beneficial to the animal health.

Effect of dietary supplementation with phytogenic blend on growth performance, apparent ileal digestibility of nutrients, intestinal morphology, and cecal microflora of broiler chickens

The effects of dietary supplementation with phytogenic blend (PB) of Aerva lanata, Piper betle, Cynodon dactylon, and Piper nigrum on growth performance, ileal nutrient digestibility, intestinal morphology, and cecal microflora were determined in a 42-day broiler feeding trial. A total of 192 broilers were assigned to 4 dietary treatments (6 replicates and 8 birds/replicate): basal diet, basal diet supplemented with antibiotic (chlortetracycline), 1% and 2% PB, respectively. The body weight gain (BWG) of starter chicks increased linearly (P = 0.023) as dietary supplementation levels of PB increased. At grower phase, broilers fed diet supplemented with 1% PB had similar BWG with the antibiotic group, but other treatments had reduced (P = 0.0001) BWG. Dietary supplementation with 1% PB resulted in the highest (P < 0.0001) BWG during the study. Feed intake was not affected by the treatments during the starter, finisher, and overall rearing periods. Broilers fed diet supplemented with 1% PB had the best (P < 0.0001) feed conversion ratio during the study. Overall, broilers fed only basal diet had the highest (P = 0.0450) mortality. Ileal organic matter (OM) digestibility increased linearly (P = 0.044) with broilers fed diet supplemented with PB, but reduced with antibiotic group. Dietary supplementation with 1% PB had the highest (P = 0.0402) ileal digestibility of tryptophan. In the duodenum, broilers fed diet supplemented with PB had longer (P = 0.0006) villi heights than the birds fed only basal diet, but similar with antibiotic group. Broilers fed diet supplemented with PB had longer (P = 0.0064) villi height in the jejunum than the antibiotic group. Bifidobacterium concentration of the cecum content showed a slight increase (P = 0.053) with increasing supplementation levels of PB. In conclusion, the current study shows that dietary supplementation with PB improves growth performance, intestinal morphology, and apparent ileal digestibility of OM and tryptophan in a dose-dependent manner with the best response at 1% inclusion level.

Impacts of Strain Variation on Response to Heat Stress and Boldo Extract Supplementation to Broiler Chickens

Simple Summary

One of the common approaches to alleviating heat-stress in poultry is nutritional manipulation using herbal extracts or their derivatives to maintain the health, welfare, and performance of birds. The present study investigated the protective effect of boldo leaf extract against the harmful effects of cyclic heat stress in two broiler strains (Arbor Acres; AA and Avian-48; AV). Administration of boldo in drinking water was able to restore growth and health traits to nearly normal values. Generally, AA chicks were better able to withstand heat stress and were also more likely to utilize boldo extract than AV chicks. The use of boldo leaf extract in poultry production can assist in mitigating the effect of heat stress, improving the antioxidant defense system, and increasing productivity and profitability.

Abstract

There is increasing interest in the use of natural antioxidant supplements in poultry diets as protection against the adverse effects of heat stress. The potential protective effect of boldo (Peumus boldus molina) leaf extract, which have antioxidant activity, were investigated against the harmful effects of heat stress in two broiler strains. Arbor Acres (AA) and Avian-48 (AV) chicks were divided into thermoneutral (TN) and heat stress (HS) groups and treated with 1 g boldo leaf extract/4 L drinking water during the heat stress period. HS reduced growth performance in both strains. The phagocytic index, phagocytic activity, and eosinophil and lymphocytes counts were significantly elevated in TN and HS AV birds but not altered in AA birds. Boldo extract treatment partially eliminated the previous negative impacts of heat stress. AA chicks were better able to withstand HS than AV chicks. Serum concentrations of total lipids and cholesterol were reduced in HS birds of both strains. Malondialdehyde, superoxide dismutase, and glutathione peroxidase levels were elevated but restored with the administration of boldo leaf extract in HS birds of both strains. Economic parameters were negatively affected by HS but restored to values close to those of the control group in boldo-treated HS birds. In conclusion, the administration of boldo leaf extract in drinking water was effective in neutralizing the harmful effects of heat stress on growth performance, blood indices, and economic parameters and improved the antioxidant defense system in heat-stressed birds.

Regulatory Functions of Fatty Acids with Different Chain Lengths on the Intestinal Health in Pigs and Relative Signaling Pathways

Intestines are not only major organs for nutrient digestion and absorption, but are also the largest immune organ in pigs. They are essential for maintaining the health and growth of piglets. Fatty acids, including short-chain fatty acids, medium-chain fatty acids, and long-chain polyunsaturated fatty acids, are important nutrients; they are a major energy source, important components of the cell membrane, metabolic substrates in many biochemical pathways, cell-signaling molecules, and play role as immune modulators. Research has shown that fatty acids exert beneficial effects on intestinal health in animal models and clinical trials. The objective of this review is to give a clear understanding of the regulatory effects of fatty acids of different chain lengths on intestinal health in pigs and their signaling pathways, providing scientific reference for developing a feeding technique to apply fatty acids to piglet diets.

Response of broiler chickens to xylanase and butyrate supplementation

A 2 × 2 factorial experiment was used to evaluate the effect of xylanase and sodium butyrate supplementation on performance, intestinal fermentation, histology, and morphometry in broiler chickens. A total of 384 Ross 308 broiler chicks (1-day-old) were allocated to 4 experimental treatments: CTR (control diet), XYL (CTR diet with 16,000 BXU/kg of xylanase), BUT (CTR diet with 1 kg/t sodium butyrate), and XYL+BUT (CTR diet plus xylanase and sodium butyrate). Each treatment had 8 replicates of 12 animals. Starter and grower diets, based on wheat and soybean meal, and water were available ad libitum. Body weight gain and feed intake were measured from 0 to 42 D, and feed conversion ratio corrected for mortality (FCR) was calculated. The profile of short-chain fatty acids in the duodenum, jejunum, ileum, and ceca digesta on days 21 and 42 was analyzed in addition to the relative weights of the different portions of the gastrointestinal tract (GIT). The villus height (VH), crypt depth (CD), and villus to crypt (VH: CD) ratio from the ileal tissue on day 42 were also evaluated. Statistical comparisons were performed using a 2-way ANOVA. Xylanase supplementation improved 42-D FCR by 5 points (P = 0.006), while butyrate did not affect 42-D FCR. On day 21, birds fed butyrate had heavier total GIT (P = 0.024), duodenum (P < 0.001), and jejunum (P = 0.025). Xylanase did not influence the relative weights in any intestinal section except the crop which was smaller in xylanase supplemented birds. At day 42, the VH: CD ratio was increased with sodium butyrate (P = 0.005). Supplementation of broiler diets with xylanase improved performance but had little effect on intestinal measures, whereas sodium butyrate influenced many of the intestinal indices with no consequence on animal performance.

Response of gastrointestinal fermentative activity and colonic microbiota to protected sodium butyrate and protected sodium heptanoate in weaned piglets challenged with ETEC F4. Arch Anim Nutr 2019;73:339-359. [PMID: 31342760 DOI: 10.1080/1745039x.2019.1641376]

This study aimed to evaluate the potential of two new fat-protected butyrate or heptanoate salts to improve gut health and control post-weaning colibacillosis in weaning piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4⁺, particularly focusing on their impact on intestinal microbiota and fermentative activity along the gastrointestinal tract (GIT). Seventy-two 21-d-old pigs were fed a plain diet (CTR) or supplemented with sodium butyrate (BUT) or sodium heptanoate (HPT), both at 0.3%. After a week of adaptation, animals were orally challenged at days 8 and 9 with 5.8 · 10⁹ and 6.6 · 10¹⁰ cfu, respectively, and were euthanised on d 4 and d 8 post-inoculation (PI) (n = 8) to collect blood, digesta and tissue samples and characterise microbial groups, pathogen loads (qPCR), fermentation, ileal histomorphometry and immune markers. Colonic microbiota was analysed by 16S rRNA gene MiSeq sequencing. Supplementing both acid salts did not compensate clinical challenge effects nor performance impairments and neither histomorphometry nor serum biomarkers. Changes in the gastric fermentative activity were registered, BUT reducing lactic acid concentrations (day 8 PI), and with HPT fewer animals presenting detectable concentrations of propionic, butyric and valeric acids. At ileum BUT increased acetic acid concentration (day 8 PI), and both additives reduced short-chain fatty acids (SCFA) in the colon. Increases in enterobacteria and coliforms counts in ileal digesta (day 4 PI, p < 0.10) and mucosa scrapes (p < 0.05) were registered although E. coli F4 gene copies were unaffected. Regarding changes in the colonic microbiota (day 4 PI), Prevotellaceae and Prevotella were promoted with BUT supplementation whereas only minor groups were modified in HPT-treated animals. Summarising, although the pathogen loads or inflammatory mediators remained unresponsive, butyrate and heptanoate showed a significant impact on microbial fermentation along the whole GIT, being able to modify different bacterial groups at the colon. It could be hypothesised that these effects might be mediated by a carry-over effect of the changes observed in gastric fermentation, but possibly also to a better nutrient digestion in the foregut as a result of the reduced colonic SCFA concentrations.

Potential relevance of pig gut content transplantation for production and research

It is becoming increasingly evident that the gastrointestinal microbiota has a significant impact on the overall health and production of the pig. This has led to intensified research on the composition of the gastrointestinal microbiota, factors affecting it, and the impact of the microbiota on health, growth performance, and more recently, behavior of the host. Swine production research has been heavily focused on assessing the effects of feed additives and dietary modifications to alter or take advantage of select characteristics of gastrointestinal microbes to improve health and feed conversion efficiency. Research on faecal microbiota transplantation (FMT) as a possible tool to improve outcomes in pigs through manipulation of the gastrointestinal microbiome is very recent and limited data is available. Results on FMT in humans demonstrating the transfer of phenotypic traits from donors to recipients and the high efficacy of FMT to treat Clostridium difficile infections in humans, together with data from pigs relating GI-tract microbiota composition with growth performance has likely played an important role in the interest towards this strategy in pig production. However, several factors can influence the impact of FMT on the recipient, and these need to be identified and optimized before this tool can be applied to pig production. There are obvious inherent biosecurity and regulatory issues in this strategy, since the donor's microbiome can never be completely screened for all possible non-desirable microorganisms. However, considering the success observed in humans, it seems worth investigating this strategy for certain applications in pig production. Further, FMT research may lead to the identification of specific bacterial group(s) essential for a particular outcome, resulting in the development of banks of clones which can be used as targeted therapeutics, rather than the broader approach applied in FMT. This review examines the factors associated with the use of FMT, and its potential application to swine production, and includes research on using the pig as model for human medical purposes.

In vitro Susceptibility and Evaluation of Techniques for Understanding the Mode of Action of a Promising Non-antibiotic Citrus Fruit Extract Against Several Pathogens

The screening for alternatives to antibiotics is an urgent need for the pharmaceutical industry. One of these alternatives seems to be the citrus fruit extracts, which are showing a significant antibacterial activity against Gram-negative and Gram-positive bacteria. One of these citrus extracts, named BIOCITRO®, is assessed in this study to elucidate its bacteriostatic and bactericidal effect and its mode of action on the important pathogens Campylobacter coli, C. jejuni, Escherichia coli, Salmonella enterica ssp. enterica, Clostridium difficile, C. perfringens, and Staphylococcus aureus. For most of the strains tested of these bacteria the product was bactericidal as well as bacteriostatic at the same concentration, and the minimum bactericidal concentrations ranged from 16 to 256 μg/mL. Regarding the mode of action, important changes in the permeability, structure, composition and morphology of the bacterial envelope were evidenced using flow cytometry, Fourier transform infrared spectroscopy and scanning electron microscopy. The main effect of the product was found over carbohydrates and polysaccharides, inducing the release of microvesicles by the cells in addition to other specific effects. During the study, the techniques used were evaluated to clarify their contribution to the knowledge of the mode of action of the product. The survival test elucidated whether the modifications displayed using other techniques affected the viability of the cells or on the contrary, the cells remained viable even with evident changes in their structure, composition or morphology. Flow cytometry showed that for some strains the proportion of cells detected with altered membrane permeability were higher than the number of non-viable cells, and therefore the damage did not affect the viability of some cells. On the contrary, some cells observed using scanning electron microscopy with no apparent damage, were demonstrated non-viable using the survival test, making this technique indispensable in studies of the mode of action of antimicrobials to make a correct interpretation of the data from other techniques.

Effects of dietary supplementation with essential oils and organic acids on the growth performance, immune system, fecal volatile fatty acids, and microflora community in weaned piglets

The present study was conducted to assess the effects of a mixture of essential oils and organic acids on the growth performance, immune system, major fecal volatile fatty acids (VFAs), and microflora community in the weaned piglets. We also evaluated the antibacterial activity of the essential oil mixture on Escherichia coli and Staphylococcus aureus. Three hundred weaned piglets (Duroc × Landrace × Yorkshire) were randomly divided into the following 3 treatment groups: basal diet (C), basal diet supplemented with the mixture of essential oils and organic acids (T1), and basal diet supplemented with antibiotics (T2). The mixture of essential oils and organic acids comprised of cinnamaldehyde (15%), thymol (5%), citric acid (10%), sorbic acid (10%), malic acid (6.5%), and fumaric acid (13.5%). In vitro studies showed that the mixture of essential oils extremely damaged the cell structure of pathogenic bacteria by deforming the membranes and disorganizing the intracellular components. In vivo studies revealed that diet supplementation with a mixture of essential oils and organic acids improved the final body weight and ADG of piglets (P < 0.05), increased the concentration of serum complement 4 (P < 0.05), and enhanced the fecal level of isovaleric acid (P < 0.05) compared with controls on day 28. Result of high-throughput sequencing revealed that: 1) a total of 1,177 and 1,162 observed taxonomic units (OTUs) were shared between all treatment groups on day 14 and 28, respectively; 2) the T1 exhibited higher (P < 0.05) beta diversity (unweighted UniFrac distance) than control and antibiotics treatment on day 28; 3) the samples in principle component analysis plot and tree of relative abundance were separated from each other based on dietary treatments and age; 4) Firmicutes and Bacteroidetes were the most 2 dominate phyla; Lactobacillus and Streptococcus were the 2 top species among the recognized microbiota; 5) T1 had higher (P < 0.05) relative abundance of Lactobacillus mucosae than control and antibiotics treatment on day 28. To conclude, the mixture of cinnamaldehyde and citric acids damaged the structure of pathogens in vitro; the mixture of essential oils and organic acids improved the growth performance, increased the fecal concentration of isovaleric acid, and modulated the microflora community in weaned piglets.

Therapeutic administration of enrofloxacin in mice does not select for fluoroquinolone resistance inCampylobacter jejuni

Enrofloxacin is registered for therapeutic use in beef cattle to treat bovine respiratory disease in Canada. A murine model was used to experimentally examine the impact of therapeutic administration of enrofloxacin on fluoroquinolone resistance development in Campylobacter jejuni. Administration of enrofloxacin to mice via subcutaneous injection or per os routes resulted in equivalent levels of bioactive enrofloxacin within the intestine, but bioactivity was short-lived (<48 h after cessation). Enrofloxacin administration did not affect densities of total bacteria, Firmicutes, or Bacteroidetes in digesta and had modest impacts on densities of Enterobacteriaceae. All mice inoculated with C. jejuni NCTC 11168 became persistently colonized by the bacterium. Enrofloxacin reduced C. jejuni cell densities within the cecal and colonic digesta for all treatments, and densities shed in feces as a function of antibiotic duration. None of the C. jejuni isolates recovered from mice after administration of enrofloxacin (n = 260) developed resistance to ciprofloxacin regardless of method or duration of administration. Furthermore, only modest shifts in the minimum inhibitory concentration of the isolates by treatment were noted. The study findings indicate that the risk posed by short-term subcutaneous administration of enrofloxacin for the development of fluoroquinolone resistance in mammals is low.

Caecal infusion of the short-chain fatty acid propionate affects the microbiota and expression of inflammatory cytokines in the colon in a fistula pig model

Short‐chain fatty acids (SCFAs), particularly butyrate, are known to suppress inflammation, and regulate the gut bacterial ecology. However, little is known about propionate. We report here that propionate infusion in the caecum dramatically affected the structure of colonic microbiota of pigs based on 16s rRNA high‐throughput sequencing. Sixteen pig models were perfused with saline or sodium propionate by a fistula in the caecum. At d 28, all pigs were slaughtered for analysing bacterial metabolites, colonic microbiota and the expression of genes related to inflammation. The results showed that caecal infusion of sodium propionate increased the concentration of propionate and decreased the butyrate concentration in colonic content. For biogenic amines, the tyramine concentration was increased, while the concentration of cadaverine was decreased by infusion of sodium propionate. Furthermore, at the level of phylum, propionate increased the abundance of Bacteroidetes and reduced the abundance of Firmicutes. Prevotella and Bacteroides counts were increased, while Turicibacter abundance was decreased at the level of genus. Real‐time qPCR showed that the expression of NF‐κB and IL‐18 was upregulated by propionate infusion, whereas no significant differences were observed for the expression of other genes related to inflammatory processes. Taken together, these results provide a new evidence for the role of short‐chain fatty acid propionate on the composition of microbial community and inflammatory cytokines.

Essential oils as alternatives to antibiotics in swine production

This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production. Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and anti-inflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions. In the past, the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals. The minimal inhibitory concentration (MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production. With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology. The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing (QS) have led to better production performance of animals fed essential oils in a number of studies. It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production. The combination of different essential oils and other compounds (synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications. High-throughput systems technologies have been developed recently, which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.

Dietary butyrate glycerides modulate intestinal microbiota composition and serum metabolites in broilers

Butyrate can modulate the immune response and energy expenditure of animals and enhance intestinal health. The present study investigated changes in the intestinal microbiota composition and serum metabolites of young broilers in response to 3,000 ppm butyrate in the form of butyrate glycerides (BG) via pyrosequencing of bacterial 16S rRNA genes and nuclear magnetic resonance (NMR). The dietary treatment did not affect the alpha diversity of intestinal microbiota, but altered its composition. Thirty-nine key operational taxonomic units (OTUs) in differentiating cecal microbiota community structures between BG treated and untreated chickens were also identified. Bifidobacterium was, in particular, affected by the dietary treatment significantly, showing an increase in not only the abundance (approximately 3 fold, P ≤ 0.05) but also the species diversity. The (NMR)-based analysis revealed an increase in serum concentrations of alanine, low-density and very low-density lipoproteins, and lipids (P ≤ 0.05) by BG. More interestingly, the dietary treatment also boosted (P ≤ 0.05) serum concentrations of bacterial metabolites, including choline, glycerophosphorylcholine, dimethylamine, trimethylamine, trimethylamine-N-oxide, lactate, and succinate. In conclusion, the data suggest the modulation of intestinal microbiota and serum metabolites by BG dietary treatment and potential contribution of intestinal bacteria to lipid metabolism/energy homeostasis in broilers.

Potential of essential oils for poultry and pigs

The increasing pressure of abolishing and/or decreasing the use of antibiotics as antimicrobial growth promoters for livestock calls for alternative solutions to sustain the efficiency of current livestock production. Among the alternatives, essential oils have a great potential and are generally considered natural, less toxic, and free from residues. Essential oils have been proven in numerous in vitro studies to exert antimicrobial effects on various pathogens. The current review touched on the basics of essential oils, and the in vivo effects of essential oils on growth, intestinal microflora, anti-oxidation, immune functionality, meat qualities as well as the possible modes of action in poultry and pigs, and the future research areas were proposed.

Priorities and Future Actions for an Effective Use of Phytotherapy in Livestock-Outputs from an Expert Workshop

This study reflects on the recognised need for more joined-up, high-quality research on phytotherapy that addresses the current societal challenges in finding alternatives to the use of antibiotics. The study applied a multidisciplinary participatory approach in an expert workshop exercise within the FP7 EU IMPRO project. Prior to this study, a literature review was elaborated on research in the field of phytotherapy as applied to farm animals, cooperation between research bodies and initiatives to reduce the use of antibiotics by using phytotherapeutic remedies. The review was delivered to the participants of the workshop so as to receive feedback on it and enrich the discussion. Different expertise, background in research or veterinary practice, and varying positions regarding phytotherapy were the criteria in targeting participants. A structured workshop was subsequently organised, with questions to experts addressing scientific validation of phytotherapy, effective treatment under farm conditions and necessary developments for the future. Challenges identified by the experts were as follows: poor study designs, lack of reproducibility of studies, poor standardisation of products, cost-benefit concerns, lack of veterinarian training and poor data availability. To overcome obstacles, the need for improved study designs for clinical trials was given priority in order to prove the efficacy of remedies and to implement a monitoring system which enables the assessment of the effectiveness of treatments in farm practice. Reflections in this report are intended to be a resource for scientists, policy makers and end users for an effective use of phytotherapy at farm level.

Effects of the intake of white wheat bread added with garlic and resistant starch: action on calcium bioavailability and metabolic parameters of growing Wistar rats

Functional bread with resistant starch and garlic improved the metabolism of calcium and lipids and the growth of beneficial gut microbiota.

Effects of several in-feed antibiotic combinations on the abundance and diversity of fecal microbes in weaned pigs

To characterize the effects of several subtherapeutic antibiotic combinations on the abundance and diversity of fecal microbes, 400 weaned pigs were selected and randomly assigned to 8 groups, where they were continuously fed different antibiotic combinations for 28 days. Then, a total of 48 pigs were randomly selected to collect feces samples for DNA extraction and 16S rRNA high-throughput sequencing. Compared with that of pigs without antibiotic administration, the diversities of fecal microbes were decreased in the pigs fed chlortetracycline (CTC), olaquindox (OLA), and either enramycin (ER) or virginiamycin (VIR), and the relative abundances of members of the phylum Bacteroidetes and the genus Prevotella were increased. Compared with that of pigs without antibiotic administration, the relative abundances of members of the phylum Proteobacteria and the genus Succinivibrio were decreased in the pigs fed CTC, a mixture of zinc bacitracin (ZB) + colistin sulfate (COL), a mixture of CTC+ZB+COL, a mixture of CTC+OLA, or a mixture of CTC+OLA+ER. α-Diversity and β-diversity were decreased (P < 0.05) in the pigs fed ZB+COL or a mixture of CTC+OLA+ER or CTC+OLA+VIR. This study provides experimental data to deepen our understanding on the effects of antibiotic combinations on intestinal microbes.

α-Galactosides present in lupin flour affect several metabolic parameters in Wistar rats

The aim of this study is to evaluate the influence of α-galactosides present in a lupin diet on metabolic parameters in growing Wistar rats.

A Comparison of Diets Supplemented with a Feed Additive Containing Organic Acids, Cinnamaldehyde and a Permeabilizing Complex, or Zinc Oxide, on Post-Weaning Diarrhoea, Selected Bacterial Populations, Blood Measures and Performance in Weaned Pigs Experimentally Infected with Enterotoxigenic E. coli

The effects of feeding a diet supplemented with zinc oxide (ZnO) or a blend of organic acids, cinnamaldehyde and a permeabilizing complex (OACP) on post-weaning diarrhoea (PWD) and performance in pigs infected with enterotoxigenic E. coli (ETEC) were examined. Additionally, changes in selected bacterial populations and blood measures were assessed. A total of 72 pigs weaned at 22 d of age and weighing 7.2 ± 1.02 kg (mean ± SEM) was used. Treatments were: base diet (no antimicrobial compounds); base diet + 3 g ZnO/kg; base diet + 1.5 g OACP/kg. Dietary treatments started on the day of weaning and were fed ad libitum for 3 weeks. All pigs were infected with an F4 ETEC on d 4, 5 and 6 after weaning. The incidence of PWD was lower in pigs fed ZnO ( p = 0.026). Overall, pigs fed ZnO grew faster ( p = 0.013) and ate more ( p = 0.004) than the base diet-fed pigs, with OACP-fed pigs performing the same ( p > 0.05) as both the ZnO- and base diet-fed pigs. Feed conversion ratio was similar for all diets ( p > 0.05). The percentage of E. coli with F4 fimbriae was affected a day by treatment interaction ( p = 0.037), with more E. coli with F4 fimbriae found in pigs fed ZnO on d 11 ( p = 0.011) compared to base diet-fed pigs. Only significant time effects ( p < 0.05) occurred for blood measures. Under the conditions of this study, inclusion of OACP gave statistically similar production responses to pigs fed ZnO, however pigs fed ZnO had less PWD compared to OACP- and the base diet-fed pigs.

Comparative efficacy of a phytogenic feed additive and an antibiotic growth promoter on production performance, caecal microbial population and humoral immune response of broiler chickens inoculated with enteric pathogens

The aim of this work was to compare the efficacy of a commercially available phytogenic feed additive (PFA) and an antibiotic growth promoter, which was bacitracin methylene disalicylate (BMD), on performance, nutrient retention, caecal colonization of bacteria and humoral immune responses against Newcastle disease in broiler chickens challenged orally with Salmonella enteritidis and Escherichia coli. One-day-old male Cobb 400 broiler chicks (n = 120) were fed with 1) a negative control (NC) diet, which is the basal diet without any added growth promoter, 2) a positive control (PC) diet, the basal diet supplemented with BMD, 500 mg/kg and 3) a diet supplemented with PFA (150 mg/kg) for 39 days and the birds were inoculated with S. enteritidis and E. coli on d 28. Supplementation of PFA improved body weight, feed conversion ratio, retention of N and crude fiber, increased fecal moisture content and decreased digesta transit time as compared with the NC and PC groups (P < 0.01). Both the PC and the PFA was found to be equally effective in controlling the surge in numbers of Salmonella and E. coli following oral inoculation of these bacteria as compared with the NC group (P < 0.05) at 24 h past inoculation. Caecal content analysis on d 39 indicated lower numbers of Salmonella, E. coli and Clostridium in the PC and PFA groups as compared with the NC group (P < 0.05). The number of Lactobacillus in the PFA group was higher than those in the NC and PC groups (P < 0.05). Humoral immune response, measured as hemagglutination inhibition titer against Newcastle disease, was better in the PC and PFA groups compared with the NC group (P < 0.05) at d 21 but the difference did not last till d 39. The heterophil to lymphocyte ratio was narrower (P < 0.001) and alkaline phosphatase activity was higher (P < 0.01) in the PFA group as compared with the NC and PC groups on d 39. It was concluded that the PFA, which is animal, environment and consumer friendly, may be used as an effective replacement for common in-feed antibiotics like BMD to enhance broiler performance especially when the birds are exposed to heavy infections on fields.

Effect of dietary inclusion of a herbal extract mixture and different oils on pig performance and meat quality

The aim of the study was to evaluate the effect of a herbal extract mixture on pig performance and meat quality. The experiment was performed on 60 fatteners (60±0.5-112±2.0kg). Group I (control) was fed with standard feed; groups II and III received the same feed supplemented with 150mg BHT or 500mg of a herbal extract mixture (sage, nettle, lemon balm and coneflower) per kg of feed, respectively. In each group, half of the animals received 4% rapeseed oil, the other half soybean oil. The herbal extracts had no effect on animal performance but significantly improved meat oxidative stability, lowered cholesterol and TI index and increased PUFA content in meat. Slight differences between animals fed with rapeseed or soybean oils were observed. Gilt meat had significantly better (P≤0.01) AI, TI, and h/H indices than barrow meat. It was concluded that herbal extracts have a beneficial effect on pork health-promoting properties due to changes in lipid fraction.

Effects of dietary supplementation of selenium-enriched probiotics on production performance and intestinal microbiota of weanling piglets raised under high ambient temperature

This study was designed to evaluate the efficacy of selenium-enriched probiotics (SeP) on production performance and intestinal microbiota of piglets raised under high ambient temperature. Forty-eight cross-bred weanling piglets (28 days old), randomly allotted into 12 pens (four piglets/pen) and four dietary treatments (three pens/treatment group), were fed ad libitum for 42 days a basal diet (Con) or the basal diet supplemented with probiotics (Pro), sodium selenite (ISe) or a SeP preparation. Blood and faecal samples were collected on days 0, 14, 28 and 42 post-treatment. The SeP group had higher final BW (p < 0.05), greater ADG (p < 0.05) and lower FCR (p < 0.01) than the Pro, ISe or Con group. The diarrhoea incidence rate of either SeP or Pro group was lower (p < 0.01) than the ISe or Con group. Blood Se concentration and GSH-Px activity were both higher (p < 0.01) in the SeP than in the Pro, ISe or Con group. On days 28 and 42, the serum concentrations of T3 were higher (p < 0.01) and T4 lower (p < 0.01) in the SeP than in the ISe group, and the T3 and T4 concentrations in the ISe group, in turn, were higher (p < 0.05) and lower (p < 0.01), respectively, than in the Pro or Con group. Also on days 28 and 42, the faecal counts of lactobacillus bacteria were higher (p < 0.01) while Escherichia coli lower (p < 0.01) in the SeP or Pro group as compared to the ISe or Con group. The results of RFLP showed that the faecal microbial flora in the SeP group changed the most (numerically) as compared to the Pro or ISe group. These results suggest that the SeP product may serve as a better alternative to antibiotics than the solo probiotics for using as a growth promoter for weanling piglets.

Influence of cardamom essential oils and seeds on growth performance, blood characteristics and immunity of broilers

This study was conducted to investigate the impact of dietary supplementation of cardamom essential oils (CEO) and powdered cardamom seeds (PCS) on the growth performance, plasma biochemistry, haematological characters, immune response and meat acceptability in broilers. In total, 300 day-old male broilers (Ross 308) were allocated to five treatments with six replicates. Dietary treatments included the basal diet as control, CEO-supplemented diets with an inclusion level of 50 (CEO1) or 100 (CEO2) mg/kg, and PCS-supplemented diets with an inclusion level of 3 (PCS1) or 6 (PCS2) g/kg. Feeding PCS1 diet improved (P < 0.05) bodyweight gain and feed conversion ratio (FCR) of broilers during the grower period (11–28 days). Moreover, broilers fed the CEO2 diet had the lowest (P < 0.05) FCR during the whole growth period (0–42 days). Higher bursa index (P < 0.05) was detected in chickens receiving CEO1 and CEO2 diets; additionally, higher spleen index (P < 0.05) was recorded in the CEO1 group at 42 days of age. Haematological parameters including red blood cell, white blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, and mean corpuscular haemoglobin concentration values were not influenced (P > 0.05) by diet. By contrast, CEO1 and CEO2 diets decreased (P < 0.05) the low-density lipoprotein cholesterol (LDL-C) concentrations compared with control diet. Plasma cholesterol level was also lower (P < 0.05) in the CEO1 group at 42 days of age. Sensory evaluation of meat samples indicated no differences (P > 0.05) among treatments for appearance, flavour, texture and overall acceptability. Our results suggest that the CEO2 diet was advantageous compared with control diet with respect to feed efficiency. Moreover, CEO1 had a positive effect on the blood cholesterol profile by decreasing the plasma cholesterol and LDL-C levels.

Effects of adding essential oil to the diet of weaned pigs on performance, nutrient utilization, immune response and intestinal health

The objective of this study was to evaluate the effects of adding essential oils to the diet of weaned pigs on performance, nutrient utilization, immune response and intestinal health. A total of 96 weaning pigs (8.37±1.58 kg) were allotted to one of three dietary treatments. The treatments consisted of an unsupplemented basal diet (negative control, NC) or similar diets supplemented with 0.01% of an essential oil product which contained 18% thymol and cinnamaldehyde (EOD) as well as a diet supplemented with 0.19% of an antibiotic mixture which provided 150 ppm chlortetracycline, 80 ppm colistin sulfate and 50 ppm kitasamycin (positive control, PC). Each treatment was provided to eight pens of pigs with four pigs per pen. Over the entire 35 d experiment, ADG and fecal score were improved (p<0.05) for pigs fed the PC and EOD compared with the NC. Dry matter and crude protein digestibility as well as lymphocyte proliferation for pigs fed the PC and EOD diets were increased significantly compared with NC (p<0.05). IGF-I levels in plasma were significantly increased (p<0.05) in pigs fed the PC diet compared with pigs fed the NC diet. Interleukin-6 concentration was lower (p<0.05) and the tumor necrosis factor-α level was higher (p<0.05) in the plasma of pigs fed the EOD diet than the NC diet. Plasma total antioxidant capacity level increased (p<0.05) in pigs fed the EOD diet compared with pigs fed the NC. Villus height to crypt depth ratio in the jejunum was greater (p<0.05) in pigs fed the PC and EOD diets than the NC. The numbers of E. coli in the cecum, colon and rectum were reduced (p<0.05) in pigs fed the PC and EOD diets compared with the control. In the colon, the ratio of Lactobacilli to E. coli was increased (p<0.05) in pigs fed the EOD diet compared with NC diet. Total aerobe numbers in the rectum were decreased (p<0.05) in pigs fed the PC and EOD diets compared with the control. Collectively, these results indicate that blends of essential oils could be a candidate for use as an alternative to traditional antibiotics in weaning pig diets.

Effects of resveratrol and essential oils on growth performance, immunity, digestibility and fecal microbial shedding in challenged piglets

A study was conducted to evaluate the effects of resveratrol and essential oils from medicinal plants on the growth performance, immunity, digestibility, and fecal microbial shedding of weaned piglets. A total of 48 weaned piglets (8 kg initial weight, 28-d-old) were randomly allotted to four dietary treatments with 3 replications of 4 piglets each. The dietary treatments were NC (negative control; basal diet), PC (positive control; basal diet+0.002% apramycin), T1 (basal diet+0.2% resveratrol), and T2 (basal diet+0.0125% essential oil blend). All piglets were orally challenged with 5 ml culture fluid containing 2.3×10⁸ cfu/ml of Escherichia coli KCTC 2571 and 5.9×10⁸ cfu/ml Salmonella enterica serover Typhimurium. The PC group (p<0.05) showed the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the experimental period, although feed conversion ratio (FCR) was improved in the T1 group (p>0.05). Serum IgG level was increased in the T1 group, whereas TNF-α levels was reduced in the supplemented groups compared to control (p<0.05). The PC diet improved the dry matter (DM) digestibility, whereas PC and T2 diets improved nitrogen (N) digestibility compared to NC and T1 diets (p<0.05). Fecal Salmonella and E. coli counts were reduced in all treatment groups compared to control (p<0.05). Fecal Lactobacillus spp. count was increased in the T2 group compared to others (p<0.05). Dietary treatments had no significant effect on fecal Bacillus spp. count throughout the entire experimental period. Based on these results, resveratrol showed strong potential as antibiotic alternatives for reversing the adverse effects of weaning stress on growth performance, immunity and microbial environment in E. coli and Salmonella-challenged piglets.