Chicken Caecal Microbiome Modifications Induced by Campylobacter jejuni Colonization and by a Non-Antibiotic Feed Additive

[À l'origine dans / Was originally part of : Fac. Méd. vétérinaire - Chaire de recherche en salubrité des viandes]Campylobacter jejuni is an important zoonotic foodborne pathogen causing acute gastroenteritis in humans. Chickens are often colonized at very high numbers by C. jejuni, up to 109 CFU per gram of caecal content, with no detrimental effects on their health. Farm control strategies are being developed to lower the C. jejuni contamination of chicken food products in an effort to reduce human campylobacteriosis incidence. It is believed that intestinal microbiome composition may affect gut colonization by such undesirable bacteria but, although the chicken microbiome is being increasingly characterized, information is lacking on the factors affecting its modulation, especially by foodborne pathogens. This study monitored the effects of C. jejuni chicken caecal colonization on the chicken microbiome in healthy chickens. It also evaluated the capacity of a feed additive to affect caecal bacterial populations and to lower C. jejuni colonization. From day-0, chickens received or not a microencapsulated feed additive and were inoculated or not with C. jejuni at 14 days of age. Fresh caecal content was harvested at 35 days of age. The caecal microbiome was characterized by real time quantitative PCR and Ion Torrent sequencing. We observed that the feed additive lowered C. jejuni caecal count by 0.7 log (p<0.05). Alpha-diversity of the caecal microbiome was not affected by C. jejuni colonization or by the feed additive. C. jejuni colonization modified the caecal beta-diversity while the feed additive did not. We observed that C. jejuni colonization was associated with an increase of Bifidobacterium and affected Clostridia and Mollicutes relative abundances. The feed additive was associated with a lower Streptococcus relative abundance. The caecal microbiome remained relatively unchanged despite high C. jejuni colonization. The feed additive was efficient in lowering C. jejuni colonization while not disturbing the caecal microbiome

Disponibilité des acides aminés en fonction des indigestibles alimentaires et endogènes : influence des traitements technologiques appliqués aux matières premières végétales utilisées en alimentation porcine

La formulation des aliments pour porcs est effectuée sur la base de la valeur nutritionnelle des matières premières. Celle-ci est généralement déterminée par des mesures de digestibilité effectuée en utilisant la technique de marquage isotopique. Deux variantes de cette technique ont été mises en œuvre sur des porcs en croissance, celle du marquage de l'animale et celle du marquage des aliments. Nous avons évalué dans le cas du marquage de l'animal la variabilité des valeurs absolues de pertes endogènes en fonction de l'échantillon plasmatique pris comme référence d'enrichissement. Nos résultats soulignent que le choix du site et du moment de prélèvement de cet échantillon a un impact plus quantitatif que qualitatif sur l'estimation des valeurs de pertes endogènes. Grâce au marquage de l'aliment, nous avons u mesurer les variations de profils de composition en acides aminés de ces pertes endogènes. Ceux-ci semblent peu affectés par le type de matière première ou le traitement technologique que nous avons mis en œuvre même si ces paramètres affectent quantitativement les pertes. Grâce à une étude conjointe in vitro et in vivo, nous avons établi que les matières premières répondaient différemment au broyage. Contrairement au blé, le pois et la maïs voient leur digestibilité augmenter linéairement avec la réduction de la taille de particules. L'effet mesuré in vivo sur la digestibilité standardisée résulte d'une augmentation de la digestibilité réelle. Les pertes endogènes peuvent être diminuées sans effet négatif sur la digestibilité réelle au moyen de traitement hydrothermiques.Formulation of pig diets is conditioned by the nutritional values ofits raw materials. This nutritional value is generally determined by in vivo digestibility trials that do not take into account the physical form of the diets offered to animals. The objective of this thesis was to assess the impacts of feed manufacturing on amino acid availability. To this purpose ileal digesta was separated between endogenous and dietary indigestible components by a isotope dilution method involving either labelling of the animals of labelling of the feedstuffs. Regarding labelling of the animals, we assessed the variability of the absolute values of the endogenous losses using the plasma sample as the enrichment reference. Our results showed that choice of time and vessel for blood sampling induces more quantitative than qualitative variations on estimations of endogenous losses. Amino acid composition of the endogenous losses was measured by use of 15N labelled feedstuffs. Our results showed that even in endogenous protein losses were quantitatively different, their amino acid profile remained stable and were neither affected by the feedstuffs studied nor by the technological treatments. Through joint in vivo and in vitro studies, we were able to show that, according to the raw materials, grinding had a different impact on amino acid digestibility. Thus, is contrast to wheat, digestibility values of pea and corn were linearly improved with particle size reduction. Technological treatments involved in feed manufacturing affect amino acid availability. The proposal of an availability criteria derived from standardised disgestibility, taking in account the metabolic cost of endogenous losses, will allow a better assessment of the bioavailability of amino acidsRENNES-Agrocampus-CRD (352382323) / SudocSudocFranceF

Contribution of erythrocytes and plasma in threonine and lysine transfer across the portal drained viscera and the liver in pigs. Effect of threonine and lysine dietary supply

Contributions of erythrocytes and plasma to threonine and lysine transport across the PDV and the liver were determined in growing pigs successively fed a threonine deficient diet and a control well-balanced diet (experiment 1) or a lysine deficient or a well-balanced diet (experiment 2). The animals were surgically prepared for insertion of chronic catheters in the mesenteric vein (MV), the portal vein (PV), a hepatic vein (HV) and the carotid artery (CA). Plasma and whole blood AA concentrations in PV, HV and CA and PV and HV blood flows were determined during 6 hours of para-aminohippuric acid constant infusion. During this period the pigs were continuously fed (1 meal per hour). The contribution of plasma to lysine and threonine transport was higher in pigs fed the well balanced diets. More than 50% of threonine and lysine appearing in the PV and in the HV are transported by the plasma. Our results suggest that erythrocytes are probably little involved in lysine and threonine transfer across the liver and digestive tract of pig continuously fed.Rôle des globules rouges et du plasma dans le transport de la lysine et de la thréonine à travers les tissus drainés par la veine porte et le foie chez le porc. Conséquences des teneurs en thréonine et en lysine des régimes. Le rôle des globules rouges et du plasma dans le transport de la lysine et de la thréonine à travers les tissus drainés par la veine porte et le foie a été étudié chez des porcs en croissance au cours de deux expériences. Dans l'expérience 1, trois animaux recevaient successivement un aliment déficitaire en thréonine puis un aliment équilibré. Dans l'expérience 2, quatre porcs recevaient successivement un aliment déficitaire en lysine puis équilibré. Les animaux étaient munis de cathéters chroniques dans une veine mésentérique, la veine porte, une veine hépatique et l'artère carotide. Les concentrations sanguines et plasmatiques en acides aminés ont été mesurées dans la veine porte, l'artère carotide et la veine hépatique. Parallèlement, les débits sanguins dans la veine porte et la veine hépatique ont été déterminés durant 6 heures d'une perfusion continue d'acide para-aminohippurique. Pendant toute la durée des prélèvements, les animaux étaient alimentés en continu. La contribution du plasma au transport de la thréonine et de la lysine est plus importante lorsque l'aliment n'est pas déficitaire en ces acides aminés. Plus de 50 % de la lysine et de la thréonine apparaissant dans la veine porte et dans la veine hépatique sont transportés par le plasma. Nos résultats suggèrent donc que les globules rouges seraient relativement peu impliqués dans les échanges de lysine et de thréonine à travers les tissus digestifs et le foie chez le porc alimenté en continu

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. Keywords: Essential oils, Organic acids, Medium chain fatty acids, Inflammation, Oxidative stress, Pig

Effect of dietary supplementation with protease on growth performance, nutrient digestibility, intestinal morphology, digestive enzymes and gene expression of weaned piglets

This study was conducted to investigate the effect of dietary protease supplementation on the growth performance, nutrient digestibility, intestinal morphology, digestive enzymes and gene expression in weaned piglets. A total of 300 weaned piglets (21 days of age Duroc × Large White × Landrace; initial BW = 6.27 ± 0.45 kg) were randomly divided into 5 groups. The 5 diets were: 1) positive control diet (PC), 2) negative control diet (NC), and 3) protease supplementations, which were 100, 200, and 300 mg per kg NC diet. Results indicated that final BW, ADG, ADFI, crude protein digestibility, enzyme activities of stomach pepsin, pancreatic amylase and trypsin, plasma total protein, and intestinal villus height were higher for the PC diet and the supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet (P < 0.05). Supplementations of 200 and 300 mg protease per kg NC diet significantly increased the ratio of villus height to crypt depth (VH:CD) of duodenum, jejunum and ileum compared with NC diet (P < 0.05). Feed to gain ratio, diarrhea index, blood urea nitrogen, and diamine oxidase were lower for the PC diet and supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet (P < 0.05). Piglets fed the PC diet had a higher peptide transporter 1 (PepT1) mRNA abundance in duodenum than piglets fed the NC diet (P < 0.05), and supplementations of 100, 200 and 300 mg protease per kg NC diet increased the PepT1 mRNA abundance in duodenum (P < 0.05) comparing with the NC diet. Piglets fed the PC diet had a higher b0,+AT mRNA abundance in jejunum than piglets fed the NC diet (P < 0.05), and supplementations of 200 and 300 mg protease per kg NC diet increased the b0,+AT mRNA abundance in jejunum and ileum comparing with the NC diet (P < 0.05). In summary, dietary protease supplementation increases growth performance in weaned piglets, which may contribute to the improvement of intestinal development, protein digestibility, nutrient transport efficiency, and health status of piglets when fed low digestible protein sources

Effects of protected complex of biofactors and antioxidants on growth performance, serum biochemistry, meat quality, and intestinal antioxidant and immunomodulatory-related gene expressions of broiler chickens

ABSTRACT: One-day-old male broiler chickens (Ross 308) were assigned to 3 dietary treatments in a completely randomized design with 8 replicates per treatment, and 4 birds per replicate. The control group was fed a basal control diet, and the 2 test groups were fed the basal control diet supplemented with 150 and 300 mg/kg of protected complex of biofactors and antioxidants [P(BF+AOX)], respectively. The P(BF+AOx) is a combination of vitamins, L-tryptophan and biofactors such as fermentation extracts (Jefo Nutrition Inc., Saint-Hyacinthe, QC, Canada). Dietary P(BF+AOX) did not affect growth performance and breast meat quality (water holding capacity, cooking loss, shear force, and texture profile analysis), but the addition of 150 mg/kg of P(BF+AOX) decreased the relative weight of liver, heart, and spleen (P < 0.05). The addition of 150 mg/kg of P(BF+AOX) tended to increase (P = 0.051) the cold carcass yield. The addition of 150 and 300 mg/kg of P(BF+AOX) decreased (P = 0.002) the cooler carcass shrink, but the relative weight of fat pad increased (P = 0.032) in chickens fed 300 mg/kg P(BF+AOx) than in those of birds fed the control diet. On the other hand, the addition of 300 mg/kg of P(BF+AOX) decreased (P = 0.041) the serum level of uric acid compared with those of birds fed the basal diet. Broiler chickens fed diets supplemented with 150 mg/kg of diet had higher (P < 0.05) mRNA expressions of jejunal SOD1 and interleukins 6 and 10 (IL-6, IL-10). The findings suggest that P(BF+AOX) could be considered as a functional nutrient in broiler diets up to a concentration of 150 mg/kg because of its favorable effects on maintaining intestinal barrier function as well as carcass traits, while excess levels (300 mg/kg) had exhibited superior effect on the serum level of uric acid compared with those of birds fed the control diet

Innovative drugs, chemicals, and enzymes within the animal production chain

Abstract The alarming number of recently reported human illnesses with bacterial infections resistant to multiple antibacterial agents has become a serious concern in recent years. This phenomenon is a core challenge for both the medical and animal health communities, since the use of antibiotics has formed the cornerstone of modern medicine for treating bacterial infections. The empirical benefits of using antibiotics to address animal health issues in animal agriculture (using therapeutic doses) and increasing the overall productivity of animals (using sub-therapeutic doses) are well established. The use of antibiotics to enhance profitability margins in the animal production industry is still practiced worldwide. Although many technical and economic reasons gave rise to these practices, the continued emergence of antimicrobial resistant bacteria is furthering the need to reduce the use of medically important antibiotics. This will require improving on-farm management and biosecurity practices, and the development of effective antibiotic alternatives that will reduce the dependence on antibiotics within the animal industry in the foreseeable future. A number of approaches are being closely scrutinized and optimized to achieve this goal, including the development of promising antibiotic alternatives to control bacterial virulence through quorum-sensing disruption, the use of synthetic polymers and nanoparticles, the exploitation of recombinant enzymes/proteins (such as glucose oxidases, alkaline phosphatases and proteases), and the use of phytochemicals. This review explores the most recent approaches within this context and provides a summary of practical mitigation strategies for the extensive use of antibiotics within the animal production chain in addition to several future challenges that need to be addressed

A Comprehensive Analysis of the Relationship Between Dose Rate and Biological Effects in Preclinical and Clinical Studies, From Brachytherapy to Flattening Filter Free Radiation Therapy and FLASH Irradiation

International audiencePurposeFor many years, the effect of dose rate (DR) was considered negligible in external beam radiation therapy (EBRT) until very-high DR (>10 Gy/min) became possible and ultrahigh DR (>40 Gy/s) showed dramatic protection of normal tissues in preclinical experiments. We propose a critical review of preclinical and clinical studies to investigate the biological and clinical effects of DR variation in the range covering brachytherapy to flattening filter free EBRT and FLASH.Methods and MaterialsPreclinical and clinical studies investigating biological and clinical DR effects were reviewed extensively. We also conducted an in silico study to assess the effect of pulse DR (DRp), taking into account the mean time between 2 tracks during the pulse.ResultsPreclinical studies have shown that an increase in DR in the range of 0.01 to 20 Gy/min (not including ultralow or ultrahigh DR) resulted in decreased survival of both normal and tumor cells. This effect was attributed primarily to increasingly unrepaired “sublethal” DNA damage with increasing the DR. However, the models and irradiation conditions have often been very different from one radiobiological study to another. Moreover, the physical parameters on the spatial and temporal microstructure of the beam were not considered systematically. In particular, the DRp was rarely mentioned. The in silico studies showed that for the same average DR, increasing DRp induced an increase of mean track rates. These results could explain the presence of more complex damage when the DRp was increased within the range of DR considered, in relation to the time-dependent probability of accumulating unrepaired, “sublethal” DNA lesions in close proximity.ConclusionsKnowledge of the beam microstructure is critical to understanding the biological impact and the clinical outcomes of radiation at the DR commonly used in radiation therapy

<i>Campylobacter</i> caecal counts in chickens at 35 days of age.

<p>No <i>Campylobacter</i> could be detected for the Campy- groups; each point represents the caecal content of a single chicken; horizontal bars illustrate the mean for each group; insufficient caecal matter was recovered from some chicken to allow the enumeration of <i>C</i>. <i>jejuni</i>; ** indicates p<0.01.</p

NMDS plot illustrating the chicken microbiome beta-diversity according to <i>C</i>. <i>jejuni</i> status.

<p>Each point represents a single chicken caecal microbiome; based on a subsample of 898 OTU.</p