Coprophagia in early life tunes expression of immune genes after weaning in rabbit ileum.

Coprophagia by suckling rabbits, i.e. ingestion of feces from their mother, reduces mortality after weaning. We hypothesized that this beneficial effect of coprophagia is immune-mediated at the intestinal level. Therefore, this study investigated immune development after weaning by analyzing the ileal transcriptome at day 35 and 49 in rabbits with differential access to coprophagia in early life. Rabbit pups had access between day 1 and 15 to (i) no feces (NF) or (ii) feces from unrelated does (Foreign Feces, FF) or (iii) feces from unrelated does treated with antibiotics (FFab). 350 genes were differentially expressed between day 35 and day 49 in suckling rabbits with access to coprophagia. These genes coded for antimicrobial peptides, a mucin, cytokines and chemokines, pattern recognition receptors, proteins involved in immunoglobulin A secretion and in interferon signaling pathway. Strikingly, prevention of coprophagia or access to feces from antibiotic-treated does in early life blunted immune development between day 35 et 49 in the ileum of rabbits. Thus, coprophagia might be crucial for the maturation of intestinal immunity in rabbits and could explain why this behavior improves survival.

Milk replacer feeding once or twice a day did not change the ruminal metabolomic profile and the microbial diversity of dairy calves from birth to weaning.

In commercial dairy production systems, feeding calves once a day could be an alternative to reduce labor expenses. Several studies comparing once (OAD) versus twice (TAD) a day milk feeding systems have not evidenced differences in calf growth, rumen development, blood parameters or health scores, but impact on ruminal microbiota remains to be investigated. The objective of this study was to determine the effects of OAD or TAD on the establishment of the ruminal microbiota and its metabolic activity. Sixteen male calves (45.9 ± 5.7 kg at birth) were involved in the trial from birth to weaning (63 d). After the colostrum phase, 2 feeding programs based on a milk replacer were tested and calves were allocated to these programs on d 5. To study the establishment of the bacterial community, ruminal fluid was obtained from each calf one hour after the morning meal at 7 (d 7), 35 (d 35) and 63 (d 63) days of age. The ruminal metabolome was evaluated at a 7 d interval from d 1 to d 63. Ruminal microbiota and metabolite profiles were characterized by 16 S rRNA gene sequencing- and by H-NMR spectroscopy, respectively. Our results showed that feeding milk replacer once or twice a day did not change the ruminal microbiota and metabolites of dairy calves from birth to weaning. Microbial data showed that diversity and richness increased with age, suggesting a shift from an heterogeneous and less diverse community after birth (d 7) to a more diverse but homogeneous community at 35 and 63 d. These findings suggest that feeding milk once a day can be successfully applied to a calf feeding system without compromising microbial establishment and functions.

Part-time grouping of rabbit does in enriched housing: effects on performances, injury occurrence and enrichment use.

Collective housing is perceived as a possible way to improve rabbit welfare, especially among adult females, which are normally individually housed. Part-time group housing seems to allow a better balance between welfare and health than continuous group housing, but practical implementation and consequences for reproductive performance have not been extensively studied. The aim of this work was to compare weight, feed intake, litter size, injury occurrence, body integrity, and spatial location of female rabbits housed part-time in group housing (PGH group, n = 32) or housed individually (IH group, n = 8). Females were grouped by opening connecting hatches between four individual enriched cages (platform, wood stick and gnawing block). Collective housing started 12 days after artificial insemination and was interrupted at the 10th day (instead of the 15th day later as originally planned) due to high injury rates and severe injuries caused by fighting. The proportion of injured females increased from 25% on the first day of grouping to 63% on the 10th day. Female weight gain during the experiment was similar in the two groups. Litter size at weaning was 9% lower in the PGH group than in the IH group (9.2 vs 10.0, P < 0.01). Platform use was recorded in 32% of the observations and was the highest during the 2 weeks before weaning (46% and 47% of total observations, P < 0.05). During the grouping period, there were at least two females in the same housing unit in 59.4% of the cases, at least two females were located on the same level in 31.3% of the cases. In conclusion, connecting individual cages is an ergonomic solution for part-time group housing, but does not prevent fights for the establishment of a social hierarchy. This is detrimental to the health and body integrity of female rabbits.

Development of a theory-based intervention to increase cognitively able frail elders' engagement with advance care planning using the behaviour change wheel.

BACKGROUND: Advance care planning (ACP) conversations support people to think about, discuss and document their beliefs, values and preferences regarding future care. This process means that should the person loose capacity in the future, care can be provided, consistent with their personal values and beliefs. The ACP process is particularly relevant for older people living with frailty (frail elders) as they are vulnerable to sudden deterioration. However, ACP is rarely undertaken by frail elders. The aim of this study was to develop an intervention to increase multidisciplinary health and social care professionals' (H&SCPs) engagement of cognitively able, domestic-dwelling frail elders with ACP. METHODS: Intervention development was guided by the Medical Research Council framework for complex interventions and the Behaviour Change Wheel. Multiple methods were used to understand ACP barriers and enablers: a systematic integrative review, a survey (n = 73 H&SCPs), and semi-structured interviews (n = 10 frail elders, n = 8 family members). A conceptual model, developed from the integrative review, underpinned data collection for the survey and interviews. Synthesis of this data, including patient and public involvement, was then used to identify H&SCPs behaviours that needed to change for ACP to be implemented and decide content and implementation for the intervention. RESULTS: Following the Behaviour Change Wheel system, and based on the findings of the review, survey and interviews, the prototype intervention, Conversations on Living and Dying (CLaD), was developed. The CLaD prototype consisted of one 3.5-hour educational skills session for H&SCPs supported by a toolkit. Content focussed on the relevance of ACP for frail elders, experience of ACP by frail elders, and strategies H&SCPs could adopt to encourage frail elders' engagement with ACP. Strategies include recognising the importance of relationships and living well now, preparing frail elders for ACP conversations and starting ACP early. Participants who took part in initial prototype refinement reported that the intervention helped them think differently about ACP and encouraged them to engage with frail elders. CONCLUSIONS: The use of behavioural theory enabled the development of CLaD, an evidence-based, theory-driven, person-centred intervention to support ACP engagement with frail elders. While feasibility testing is required, initial prototype refinement demonstrated that H&SCPs found the intervention to be acceptable, engaging, and clinically valuable in their practice with frail elders and their families.

[Health Data Hub in France, use cases in oncology and radiation oncology]. / HealthDataHub ; plateforme des données de santé en France, application à l'oncologie radiothérapie.

Health data financed by the French national solidarity system constitute a common heritage. Such data should be exploited to optimize care while complying with ethics and fundamental rights of citizens. The creation of the Health Data Hub (HDH) was allowed by the 24 July 2019 Law on the organization and transformation of the French health system. Its objective is to enable authorized innovative project leaders to access non-nominative data via a state-of-the-art secure technological platform. It appears to be one of the strong points of the French Artificial Intelligence strategy. This structure is a public interest group which associates 56 stakeholders, mostly from the public authorities. It implements, in partnership with the National Health Insurance Fund, the major strategic orientations relating to the National Health Data System set by the French State and the Ministry of Solidarity and Health. The Health Data Hub allows cross-reference of consolidated databases with SNDS data. Several use cases are under construction. The creation of relational databases in radiation oncology is also possible through specific strategies to get pseudonymized data from the various radiotherapy software programs upstream of the Health Data Hub.

Evolution of gut microbial community through reproductive life in female rabbits and investigation of the link with offspring survival.

The digestive microbiota plays a decisive role in shaping and preserving health throughout life. Rabbit younglings are born with a sterile digestive tract but then it gets progressively colonised by the microbiota of the nursing mother, by entering in contact with or ingesting the maternal droppings present in the nest. Here we posit that (i) offspring survival and (ii) lifespan of female rabbits are linked to how diverse their microbiota are. To test the hypothesis that maternal microbiota evolves in females having had different levels of offspring survival in their lifetime, we obtained 216 hard faecal samples from 75 female rabbits at ages 19.6, 31.6, 62.6 and 77.6 weeks. The annual mean offspring survival (MOS) at 64 days was calculated for each female then crossed against three alpha-diversity indexes (operational taxonomic units (OTUs), inverse Simpson index and Shannon index). Age was also analysed against these three parameters. The alpha-diversity indexes of the female faecal microbiota did not correlate with MOS, but they did decrease with age (e.g. from 712 OTUs at age 19.6 weeks to 444 OTUs at 77.6 weeks; P < 0.05). The age effect was also found in beta-diversity non-metric multidimensional scaling plots using the Bray-Curtis dissimilarity index and the unweighted UniFrac index but not for MOS. The ability of the microbiota composition from the faecal samples of young females (19.6 weeks old) to predict their lifespan was also evaluated. After subdividing the initial population into two classes (females that weaned a maximum of three litters and females living longer), we found no clear distinction between these two classes. To our knowledge, this is the first long-term study to characterise the gut microbiota of adult female rabbits through their reproductive life, thus laying foundations for using the gut microbiota data and its influence in studies on adult rabbits.

Insights into suckling rabbit feeding behaviour: acceptability of different creep feed presentations and attractiveness for sensory feed additives.

In young rabbit, digestive disorders are frequently observed around weaning. Stimulating the onset of feed intake in the suckling rabbit might be a way to promote gut health. The aim of this study was to determine the rabbit's acceptability for different feed presentations and its preferences for flavours at an early stage of life. Two trials were conducted to evaluate the effects of physical form and flavouring on creep feed attractiveness. All the diets tested were provided in the nest from 3 to 17 days, and the daily intake per litter was recorded as of 8 days of age. In the first trial, five feed presentations were tested separately (n = 60 litters). Three dry presentations were chosen: commercial pellet (P), crumb from commercial pellet (cP) and crumb from beet pulp pellet (cBP). Hydrated feeds were also provided with either raw fodder beetroot (B) or a semi-solid feed in agar gel form produced with fodder beetroot juice and pulp (gB). In the second trial, double-choice tests were performed on four feed gels (n = 72 litters), leading to six comparison treatments. These agar gels were made of pellet mash without or with a sensory additive: one non-odorised control gel and three gels with 0.20% banana flavour, 0.06% red berry flavour and 0.10% vanilla flavour, respectively. In the first trial, kits ate more gB in fresh matter than other feed presentations (P < 0.001), with a total intake of 7.0 ± 1.8 g/rabbit from 8 to 17 days. In DM, the total consumption of pellets P (1.6 ± 0.4 g of DM/rabbit) was the highest together with the gB form (1.4 ± 0.4 g of DM/rabbit), whereas cBP was barely consumed (0.3 ± 0.1 g of DM/rabbit). Gel feed supplemented with vanilla was slightly more consumed than other flavoured and non-odorised gels (relative consumption of 57% when compared to control gel; P = 0.001). The gel feed intake was independent of the milk intake but was correlated with the litter weight at 3 days (r = 0.40, P < 0.001). In both trials, rabbit growth before and after weaning was not affected by the type of creep feed provided. Our results confirmed that providing creep feed promotes the solid intake of rabbits at early stages. Gel feed form motivated rabbits to eat and vanilla flavour supplementation increased the feed palatability. Those creep feed characteristics should be explored further for seeking effective stimulation of the onset of the feed intake in suckling rabbit.

Post-Doc Interviews in the Life Sciences: An Often-Overlooked Process that Is Susceptible to Bias.

Post-doctoral training is a critical career stage for researchers in the life sciences, yet interviewing for a post-doctoral position is largely an unregulated process. Without regulation, interviews are susceptible to unconscious biases that may lead to discrimination against certain demographic groups (e.g., women and minorities). Using data from an online survey of post-docs, we show that interview procedures for post-doctoral positions in the life sciences are correlated with several factors (e.g., candidate demographics) in ways that may bias the outcome of interviews. We discuss key components of interviews and suggest that conducting standardized, well-planned interviews that are less susceptible to unconscious biases may help increase the retention of women and under-represented minorities in the life sciences.

Entrevistas postdoctorales en ciencias de la vida: un proceso que a menudo se pasa por alto y que es susceptible al sesgo (Post-doc interviews in the life sciences: An often-overlooked process that is susceptible to bias) La capacitación posdoctoral es una etapa profesional crítica para los investigadores en ciencias de la vida, pero la entrevista para un puesto postdoctoral es en gran medida un proceso no regulado. Sin regulación, las entrevistas son susceptibles a sesgos inconscientes que pueden conducir a la discriminación contra ciertos grupos demográficos (por ejemplo, mujeres y minorías). Utilizando datos de una encuesta en línea de documentos post-doctorales, mostramos que los procedimientos de entrevista para puestos post-doctorales en ciencias de la vida están correlacionados con varios factores (por ejemplo, los demográficos de los candidatos) en formas que pueden sesgar el resultado de las entrevistas. Discutimos los componentes clave de las entrevistas y sugerimos que realizar entrevistas estandarizadas y bien planificadas que sean menos susceptibles a sesgos inconscientes puede ayudar a aumentar la retención de mujeres y minorías subrepresentadas en las ciencias de la vida. Translated to Spanish by YE Jimenez (yordano_jimenez@brown.edu).

Rumen microbiota and dietary fat: a mutual shaping.

Although fat content in usual ruminant diets is very low, fat supplements can be given to farm ruminants to modulate rumen activity or the fatty acid (FA) profile of meat and milk. Unsaturated FAs, which are dominant in common fat sources for ruminants, have negative effects on microbial growth, especially protozoa and fibrolytic bacteria. In turn, the rumen microbiota detoxifies unsaturated FAs (UFAs) through a biohydrogenation (BH) process, transforming dietary UFAs with cis geometrical double-bonds into mainly trans UFAs and, finally, into saturated FAs. Culture studies have provided a large amount of data regarding bacterial species and strains that are affected by UFAs or involved in lipolysis or BH, with a major focus on the Butyrivibrio genus. More recent data using molecular approaches to rumen microbiota extend and challenge these data, but further research will be necessary to improve our understanding of fat and rumen microbiota interactions.

Foraging in an unsteady world: bumblebee flight performance in field-realistic turbulence.

Natural environments are characterized by variable wind that can pose significant challenges for flying animals and robots. However, our understanding of the flow conditions that animals experience outdoors and how these impact flight performance remains limited. Here, we combine laboratory and field experiments to characterize wind conditions encountered by foraging bumblebees in outdoor environments and test the effects of these conditions on flight. We used radio-frequency tags to track foraging activity of uniquely identified bumblebee (Bombus impatiens) workers, while simultaneously recording local wind flows. Despite being subjected to a wide range of speeds and turbulence intensities, we find that bees do not avoid foraging in windy conditions. We then examined the impacts of turbulence on bumblebee flight in a wind tunnel. Rolling instabilities increased in turbulence, but only at higher wind speeds. Bees displayed higher mean wingbeat frequency and stroke amplitude in these conditions, as well as increased asymmetry in stroke amplitude-suggesting that bees employ an array of active responses to enable flight in turbulence, which may increase the energetic cost of flight. Our results provide the first direct evidence that moderate, environmentally relevant turbulence affects insect flight performance, and suggest that flying insects use diverse mechanisms to cope with these instabilities.

Impact of feed restriction and housing hygiene conditions on specific and inflammatory immune response, the cecal bacterial community and the survival of young rabbits.

Limiting the post-weaning intake of the young rabbit is known to improve its resistance to digestive disorders, whereas a degradation of its housing hygiene is assumed to have a negative impact on its health. This study aims at providing insights into the mechanism of digestive health preservation regarding both host (growth and immune response) and its symbiotic digestive microbiota. A 2×2 factorial design from weaning (day 28) to day 64 was set up: ad libitum intake or restricted intake at 70% of ad libitum, and high v. low hygiene of housing (n=105 per group). At day 36 and day 45, 15 animals/group were subcutaneously immunized with ovalbumin (OVA) to assess their specific immune response. Blood was sampled at 36, 45, 57 and 64 days of age to determine total and anti-OVA immunoglobulin type G (IgG) and haptoglobin levels. The cecal bacterial community was explored (18 per group) by 454 pyrosequencing of genes coding for the 16S ribosomal RNA, whereas cecal pH, NH3 and volatile fatty acid (VFA) concentrations were measured to characterize fermentative activity. A 30% reduction in feed intake reduced the growth by only 17% (P<0.001), and improved the feed conversion ratio by 15% (P<0.001), whereas the degradation of hygiene conditions slightly decreased the feed intake in ad libitum fed rabbits (-3.5%, P<0.02). As poor hygiene conditions did not affect weight gain, feed conversion was improved from day 42 (P<0.05). Restricted feeding led to a lower mortality between day 28 and day 40 (P=0.047), whereas degraded hygiene conditions decreased overall morbidity (7.8% v. 16.6%; P<0.01). Both a reduced intake and low hygiene conditions of housing affected microbiota composition and especially dominant genera belonging to the Ruminococcaceae family (P<0.01). Moreover, low hygiene was associated with a higher Ruminococcaceae/Lachnospiraceae ratio (3.7 v. 2.4; P<0.05). Cecal total VFA and pH were increased (+19%; P<0.001) and decreased (-0.1 pH unit; P<0.05), respectively, in feed-restricted rabbits. Neither specific anti-OVA IgG nor haptoglobin was affected by treatments. Total IgG concentrations were the highest in animals raised in poor hygiene conditions after 8 days of restriction, but decreased after 19 days of restriction in high hygiene conditions (-2.15%; P<0.05). In conclusion, the degradation of hygiene conditions failed to induce a systematic specific and inflammatory response in rabbit, but reduced morbidity instead. Our results suggest that the microbiota composition would be a helpful source of biomarkers of digestive health.

Influence of feeding strategy and diet for reproductive rabbit does on intake, performances, and health of young and females before and after weaning.

This study aimed to determine the influences of feeding strategy and diet for reproductive females on feed intake, BW, reproductive performances, and milk composition and their effects on kit performances from birth (d 0) to 70 d of age (d 70). A total of 133 does followed for 3 reproductive cycles and their offspring, 2,322 kits from 236 litters, were divided into 3 experimental groups that differed only by the diet offered to the doe. Three experimental diets were used: a reproduction (Repro) diet (11.01 MJ DE/kg, 24.0 g lipids/kg, 161 g starch/kg, and 343 g/kg NDF), a lactation (Lact) diet (11.88 MJ DE/kg, 49.0 g lipids/kg, 161 g starch/kg, and 302 g/kg NDF), and a fattening (Fatt) diet (9.73 MJ DE/kg, 23.0 g lipids/kg, 70 g starch/kg, and 415 g/kg NDF). In group RR, does received feed Repro throughout the study (d 0 to 42 of each cycle). In group RF, does received diet Repro from d 0 to 25 and d 35 to 42 and diet Fatt from d 25 to 35. In group LR, does received diet Lact from d 0 to 25 and diet Repro from d 25 to 42. Kits in all groups received diet F from d 18 to 70, where intake was restricted from d 35 to 63. Doe BW was similar throughout the study (4,495 g; > 0.05). Doe feed intake differed only from weaning to the subsequent kindling (+7.8% in group RF; = 0.042). Reproductive performances were similar, except for litter weight at birth (+3.6% in group LR; = 0.029). From d 0 to 25, a negative energy balance was observed in does yet most markedly in group LR (-8.61 MJ vs. -3.15 and -2.39 for groups RF and RR, respectively; < 0.01). Milk intake per kit was greater in group LR than in the other 2 groups at 17 d (+14.5%; < 0.001) and 23 d (+14.9%; < 0.05). Kit BW was highest in group LR at 18 and 25 d (+10.1% and +8.2%, respectively; < 0.01), but no difference was observed at 35 or 70 d ( > 0.05). Feed intake per kit from d 18 to 25 was greater in groups RR and RF than in group LR (+26%; < 0.001) and greater in group RF than in group LR from d 25 to 35 (+8%; < 0.05). Feed intake, when fed ad libitum (63 to 70 d), was similar in all groups ( = 0.292). Kit mortality before weaning was similar in all groups (8.1%; > 0.05) but was lowest in group RF after weaning compared to groups RR and LR (1.7 vs. 4.8 and 5.8%, respectively; < 0.001). Our results suggest that stimulating milk production through the incorporation of fat at the beginning of lactation offers few benefits for females and had a negative effect on early solid feed intake, which could explain animal health after weaning.

Outcomes after cryoablation vs. radiofrequency in patients with paroxysmal atrial fibrillation: impact of pulmonary veins anatomy.

AIMS: Pulmonary vein isolation is the mainstay of treatment in catheter ablation of paroxysmal atrial fibrillation (AF). Cryoballoon ablation has been introduced more recently than radiofrequency ablation, the standard technique in most centres. Pulmonary veins frequently display anatomical variants, which may compromise the results of cryoballoon ablation. We aimed to evaluate the mid-term outcomes of cryoballoon ablation in an unselected population with paroxysmal AF from an anatomical viewpoint. METHODS AND RESULTS: Consecutive patients with paroxysmal AF who underwent a first procedure of cryoballoon ablation or radiofrequency were enrolled in this single-centre study. All patients underwent systematic standardized follow-up. Comparisons between radiofrequency and cryoballoon ablation (Arctic Front™ or Arctic Front Advance™) were performed regarding safety and efficacy endpoints, according to pulmonary vein (PV) anatomical variants. A total of 687 patients were enrolled (376 radiofrequency and 311 cryoballoon ablation). Baseline characteristics and distribution of PV anatomical variants were generally similar in the groups. After a mean follow-up of 14 ± 8 months, there was no difference in the incidence of relapse (17.0% cryoballoon ablation vs. 14.1% radiofrequency, P = 0.25). We observed no interaction of PV anatomical variants on mid-term procedural success. CONCLUSION: Our findings suggest that mid-term outcomes of cryoballoon ablation for paroxysmal AF ablation are similar to those of radiofrequency, regardless of PV anatomy. The presence of anatomical variants of PVs should not discourage the referral of patients with paroxysmal AF for cryoballoon ablation.

Early modulation of the cecal microbial activity in the young rabbit with rapidly fermentable fiber: impact on health and growth.

This study aimed at comparing various diets predicted to induce different stimulations of the cecal microbial activity of the young rabbit fed ad libitum from 16 to 70 d of age: i) a diet enriched with rapidly fermentable fiber expected to stimulate the cecal microbial activity (RFF group); ii) a control diet with a standard composition (C group); iii) and the same control diet with tiamulin and apramycin antibiotics, expected to inhibit the microbial activity (C+AB group). A total of 398 rabbits were used from 42 litters and weaned at 28 d of age. An in vivo digestibility trial was performed on 36 rabbits of 42 to 46 d of age housed in individual metabolic cages. The feed intake and growth rates were lower in the RFF group compared with the C+AB group (-15% in ADFI and -11% in ADG, P<0.001), with a lower weight of -183 g at 70 d (P<0.001). No significant difference was found on ADG and final BW between the RFF and the C groups, but the RFF diet allowed a better G:F ratio at postweaning (P<0.01). The digestion of soluble fiber (total dietary fiber minus NDF) was greater for the RFF group. The C+AB diet had a positive effect on the postweaning morbidity rate (P<0.05) but did not affect the mortality rate and the health risk index (morbidity and mortality). Conversely, the RFF diet appeared to reduce the mortality rate compared with the C+AB diet, especially before 41 d of age. Concerning the cecal microbial activity, a supply of RFF in the diet increased the cecal VFA concentrations (+28% vs. C+AB and +22% vs. C, P<0.001) and lowered the pH. The VFA pattern was affected at 45 and 60 d, with a dominance of acetate in the RFF group (+4% vs. C+AB and C groups, P<0.001) instead of butyrate in the C+AB and C groups (-3.6% and -5% vs. C+AB and C, respectively, P<0.001). Antibiotics addition (C+AB group) reduced the VFA concentration, but only after weaning (-25% at 45 d of age) without changing the fermentation pattern. In conclusion, early intake of RFF in young rabbits stimulated the cecal microbial activity, and reduced the voluntary feed intake, leading to a reduced G:F ratio.

Lactobacillus sakei modulates mule duck microbiota in ileum and ceca during overfeeding.

The supplementation with Lactobacillus sakei as probiotic on the ileal and cecal microbiota of mule ducks during overfeeding was investigated using high-throughput 16S rRNA gene-based pyrosequencing and real-time PCR. The ducks were overfed with or without L. sakei for 12 d with 56% ground corn and 42% whole corn. Samples were collected before the overfeeding period (at 12 wk), at 13 wk (meal 12 of overfeeding), and at 14 wk (meal 24), 3 h postfeeding. Whatever the digestive segment and the level of intake, Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla in the bacterial community of mule ducks (at least 90%). Before overfeeding, ileal samples were dominated by Clostridia, Bacteroidia, and Gammaproteobacteria (80% and up), and cecal samples by Bacteroidia and Clostridia (around 85%). The richness and diversity decreased in the ileum and increased in the ceca after overfeeding. Overfeeding increased the relative abundance of Firmicutes and especially the Lactobacillus group in ileal samples. Nonmetric multidimensional scaling profiles separated the bacterial communities with respect to overfeeding only in cecal samples. Richness indicators decreased after L. sakei has been added at mid-overfeeding only in the ileum. In the ceca, the decrease of these indexes only occurred at the end of overfeeding. The addition of L. sakei triggers major changes in the ileum, whereas the ceca are not affected. Lactobacillus sakei decreased the relative abundance of Bacteroides at mid-overfeeding and the relative abundance of Enterobacteria at the end of overfeeding in the ileum.

Coprophagous behavior of rabbit pups affects implantation of cecal microbiota and health status.

During the first few weeks after delivery, female rabbits excrete fecal pellets, which are ingested by their pups. We hypothesized that maternal excretion of hard fecal pellets and the coprophagous behavior of their pups were involved in cecal microbiota implantation. Four groups were compared: in 1 group (FM), pups had free access to maternal fecal pellets; in a second group, ingestion of feces was prevented (NF); and in 2 additional groups, pups had access only to fecal pellets excreted by foreign females receiving either no antibiotic (FF) or tiamulin and tetracycline (FFab). A total of 109 litters in 3 batches were used to quantify excretion and ingestion of feces and mortality. Bacterial composition was assessed by 454 pyrosequencing of the V3 to V4 region of 16S RNA genes and fermentative measurements in 128 rabbits of 1 batch at age 14, 35, 49, and 80 d with 8 rabbits per group for each age with 2 rabbits per litter. The number of fecal pellets excreted by does from 2 to 20 d after delivery ranged widely, but was similar among groups (16.1 ± 12.6 fecal pellets/doe). The excretion peaked during the first 6 d after delivery. Foreign fecal ingestion (FF and FFab groups) was 3 times greater (P < 0.001) than ingestion of maternal feces (9.9 ± 7.8). Ingestion of feces in the FF group was greater than in the FFab groups (35.6 ± 9.3 vs. 29.5 ± 9.7; P < 0.05). Compared with the FM group, ingestion of feces in the FF and FFab groups began later (6 to 7 d vs. 2 to 3 d after birth) and peaked at 14 to 17 d (4.0 ± 1.8 hard fecal pellets·litter(-1) · d(-1)) and 13 to 15 d (3.5 ± 1.7 hard fecal pellets litter(-1) d(-1)), respectively. During the 36 to 49 d period, the FF and NF groups exhibited the least (2.8%) and greatest (9.5%) mortality, respectively (P = 0.03). At age 14 d, the cecal bacterial community was dominated by Bacteroidetes phyla (63.3 ± 15.1%), Bacteroidaceae family (36.0 ± 18.8%), and Bacteriodes genus (36.0 ± 2.3%). With increasing age, Firmicutes phyla, Lachnospiraceae, and Ruminococcaceae families became the dominant taxa (92.0 ± 4.7, 44.0 ± 13.7, 37.9 ± 11.6% at age 80 d, respectively). Impairment of fecal ingestion delayed this ecological succession, with greater and lower relative abundance of Bacteroidaceae and Ruminococcaceae, respectively, than in the other 3 groups at age 35 d (P < 0.10). In conclusion, although excretion of hard fecal pellets by does ranged widely, the coprophagous behavior of their pups affected the implantation of cecal bacterial microbiota.

OligoSpecificitySystem: global matching efficiency calculation of oligonucleotide sets taking into account degeneracy and mismatch possibilities.

Oligonucleotide sets are widely used in molecular biology to target a group of nucleic acid sequences using Polymerase Chain Reaction (PCR)-based technologies. Currently, the global matching efficiency of an oligonucleotide set is considered to be equal to the lower matching efficiency calculated for each oligonucleotide. However, sequences matching the limiting oligonucleotide did not always match the other oligonucleotide of the set, resulting in a biased evaluation of the matching efficiency. The OligoSpecificitySystem program avoid this bias by calculations of the real global matching efficiency of oligonucleotide sets. It can process all kinds of oligonucleotide sets, including the number of oligonucleotides, base pair degeneracy occurrences or mismatch occurrences.

Establishment of ruminal bacterial community in dairy calves from birth to weaning is sequential.

AIM: Establishment of ruminal bacterial community in dairy calves. METHODS AND RESULTS: Rumen bacterial community was analysed on 6 calves bred according to commercial practices from day one to weaning at day 83 of age, using 454 16S rRNA-based pyrosequencing. Samples taken at day 1 did not produce amplicons. Analysis of data revealed a three-stage implantation process with a progressive but important shift of composition. At day 2, the bacterial community was mainly composed of Proteobacteria (70%) and Bacteroidetes (14%), and Pasteurellaceae was the dominant family (58%). The bacterial community abruptly changed between days 2 and 3, and until day 12, dominant genera were Bacteroides (21%), Prevotella (11%), Fusobacterium (5%) and Streptococcus (4%). From 15 to 83 days, when solid food intake rapidly increased, Prevotella became dominant (42%) and many genera strongly decreased or were no longer detected. A limited number of bacteria genera correlated with feed intake, rumen volatile fatty acids and enzymatic activities. CONCLUSION: The ruminal bacterial community is established before intake of solid food, but solid food arrival in turn shapes this community. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides insight into the establishment of calves' rumen bacterial community and suggests a strong effect of diet.

Capture success and efficiency of dragonflies pursuing different types of prey.

The dynamics of predator-prey interactions vary enormously, due both to the heterogeneity of natural environments and to wide variability in the sensorimotor systems of predator and prey. In addition, most predators pursue a range of different types of prey, and most organisms are preyed upon by a variety of predators. We do not yet know whether predators employ a general kinematic and behavioral strategy, or whether they tailor their pursuits to each type of prey; nor do we know how widely prey differ in their survival strategies and sensorimotor capabilities. To gain insight into these questions, we compared aerial predation in 4 species of libelluid dragonflies pursuing 4 types of dipteran prey, spanning a range of sizes. We quantified the proportion of predation attempts that were successful (capture success), as well as the total time spent and the distance flown in pursuit of prey (capture efficiency). Our results show that dragonfly prey-capture success and efficiency both decrease with increasing size of prey, and that average prey velocity generally increases with size. However, it is not clear that the greater distances and times required for capturing larger prey are due solely to the flight performance (e.g., speed or evasiveness) of the prey, as predicted. Dragonflies initiated pursuits of large prey when they were located farther away, on average, as compared to small prey, and the total distance flown in pursuit was correlated with initial distance to the prey. The greater initial distances observed during pursuits of larger prey may arise from constraints on dragonflies' visual perception; dragonflies typically pursued prey subtending a visual angle of 1°, and rarely pursued prey at visual angles greater than 3°. Thus, dragonflies may be unable to perceive large prey flying very close to their perch (subtending a visual angle greater than 3-4°) as a distinct target. In comparing the performance of different dragonfly species that co-occur in the same habitat, we found significant differences that are not explained by body size, suggesting that some dragonflies may be specialized for pursuing particular types of prey. Our results underscore the importance of performing comparative studies of predator-prey interactions with freely behaving subjects in natural settings, to provide insight into how the behavior of both participants influences the dynamics of the interaction. In addition, it is clear that gaining a full understanding of predator-prey interactions requires detailed knowledge not only of locomotory mechanics and behavior, but also of the sensory capabilities and constraints of both predator and prey.