Explore the vast range of titles available.

Background Gut microbial colonization and development of immune competence are intertwined and are influenced by early-life nutritional, environmental, and management factors. Perturbation of the gut microbiome at young age affects the crosstalk between intestinal bacteria and host cells of the intestinal mucosa. Results We investigated the effect of a perturbation of the normal early life microbial colonization of the jejunum in 1-day old chickens. Perturbation was induced by administering 0.8 mg amoxicillin per bird per day) via the drinking water for a period of 24 h. Effects of the perturbation were measured by 16S rRNA profiling of the microbiome and whole genome gene expression analysis. In parallel to what has been observed for other animal species, we hypothesized that such an intervention may have negative impact on immune development. Trends were observed in changes of the composition and diversity of the microbiome when comparing antibiotic treated birds with their controls. in the jejunum, the expression of numerous genes changed, which potentially leads to changes in biological activities of the small intestinal mucosa. Validation of the predicted functional changes was performed by staining immune cells in the small intestinal mucosa and a reduction in the number of macrophage-like (KUL01 + ) cells was observed due to a direct or indirect effect of the antibiotic treatment. We provide evidence that a short, early life antibiotic treatment affects both the intestinal microbiota (temporarily) and mucosal gene expression over a period of 2 weeks. Conclusion These results underscore the importance of early life microbial colonization of the gut in relation to immune development and the necessity to explore the capabilities of a variety of early life dietary and/or environmental factors to modulate the programming for immune competence in broilers.

Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome of infectious diseases. Therefore psychoneuro-immunological intervention may prove to be a successful approach to diminish the impact of diseases and antibiotics use. This study was designed to investigate the effect of social and environmental enrichment on the impact of disease, referred to as \"disease susceptibility\", in pigs using a co-infection model of PRRSV and A. pleuropneumoniae. Twenty-eight pigs were raised in four pens under barren conditions and twenty-eight other pigs were raised in four pens under enriched conditions. In the enriched pens a combination of established social and environmental enrichment factors were introduced. Two pens of the barren (BH) and two pens of the enriched housed (EH) pigs were infected with PRRSV followed by A. pleuropneumoniae, the other two pens in each housing treatment served as control groups. We tested if differences in disease susceptibility in terms of pathological and clinical outcome were related to the different housing regimes and if this was reflected in differences in behavioural and immunological states of the animals. Enriched housed pigs showed a faster clearance of viral PRRSV RNA in blood serum (p = 0.014) and histologically 2.8 fold less interstitial pneumonia signs in the lungs (p = 0.014). More barren housed than enriched housed pigs developed lesions in the lungs (OR = 19.2, p = 0.048) and the lesions in the barren housed pigs showed a higher total pathologic tissue damage score (p<0.001) than those in enriched housed pigs. EH pigs showed less stress-related behaviour and differed immunologically and clinically from BH pigs. We conclude that enriched housing management reduces disease susceptibility to co-infection of PRRSV and A. pleuropneumoniae in pigs. Enrichment positively influences behavioural state, immunological response and clinical outcome in pigs.

EC Directive 2001/93 requires that all pigs have access to proper investigation and manipulation materials. Intensively farmed pigs in Europe are frequently provided with a short metal chain with or without an indestructible object attached to the chain. To date authorities are regarding this as proper enrichment, perhaps with (in)direct reference to the RICHPIG model as a justification. However, it has become increasingly clear that the chains do not provide proper enrichment, and that adding an indestructible object to the end of the chain may even reduce rather than improve pig welfare. To test this hypothesis an expert survey was conducted containing 26 more or less compound questions. On a scale from 0 to 10 experts specified their level of agreement with the hypothesis, the prevalence and welfare scores of nine indestructible enrichment materials. In total 36 experts, mostly pig-welfare scientists, responded (response rate: 39%). Indestructible objects are less prevalent in countries that provide straw (like Sweden and the UK) and outside the EU (US). They are more prevalent in the Netherlands, Belgium, France and Finland, while the prevalence seems to be low in Spain. Balls, wood and pipes were provided most frequently: hard wood especially in the UK (as specified in farm assurance); indestructible balls and pipes in Germany and the Netherlands. The experts' score for agreement with the hypothesis was only 4.6 on average (scale 0-10; n = 25). Enrichment materials, ranked from high to low welfare score, were grouped in 5 significance levels as indicated by different superscripts based on Wilcoxon signed rank tests: Branched chains (5.1a), Chain on the floor (4.4b), Hard wood (3.7bc), Pipe (3.5c), Bare chain (3.3c), Short chain (3.1d), Small ball (2.8d), Big ball (2.5d), and Chain hanging too high (1.3e). Branched chains scored significantly better than all other indestructible materials and its welfare score (5.1 on average) was close to the pre-defined level of acceptability (5.5 on a scale from 0, worst, to 10, best). The welfare benefits of adding balls, pipes or hard wood to the metal chain were marginal, and well below what the experts considered acceptable enrichment. The branched-chains design, by contrast, appears to be the most viable alternative. It involves providing a longer chain, i.e. with the free end reaching to floor level, adding 'branches', i.e. several short chains ending at the nose height of the pigs, and providing more chains per pen (i.e. 1 branched chain per 5 pigs). Branched chains should be implemented widely and in the short term as a first step towards, and benchmark for, providing proper enrichment to intensively-farmed pigs.

For integrated pest management (IPM) programs to be maximally effective, monitoring of the growth and decline of the pest populations is essential. Here, we present the validation results of a new automated monitoring device for the poultry red mite (Dermanyssus gallinae), a serious pest in laying hen facilities world-wide. This monitoring device (called an “automated mite counter”) was validated in experimental laying hen cages with live birds and a growing population of D. gallinae. This validation study resulted in 17 data points of ‘number of mites counted’ by the automated mite counter and the ‘number of mites present’ in the experimental laying hen cages. The study demonstrated that the automated mite counter was able to track the D. gallinae population effectively. A wider evaluation showed that this automated mite counter can become a useful tool in IPM of D. gallinae in laying hen facilities.

It may become advantageous to keep human-managed animals in the social network groups to which they have adapted. Data concerning the social networks of farm animal species and their ancestors are scarce but essential to establishing the importance of a natural social network for farmed animal species. Social Network Analysis (SNA) facilitates the characterization of social networking at group, subgroup and individual levels. SNA is currently used for modeling the social behavior and management of wild animals and social welfare of zoo animals. It has been recognized for use with farm animals but has yet to be applied for management purposes. Currently, the main focus is on cattle, because in large groups (poultry), recording of individuals is expensive and the existence of social networks is uncertain due to on-farm restrictions. However, in many cases, a stable social network might be important to individual animal fitness, survival and welfare. For instance, when laying hens are not too densely housed, simple networks may be established. We describe here small social networks in horses, brown bears, laying hens and veal calves to illustrate the importance of measuring social networks among animals managed by humans. Emphasis is placed on the automatic measurement of identity, location, nearest neighbors and nearest neighbor distance for management purposes. It is concluded that social networks are important to the welfare of human-managed animal species and that welfare management based on automatic recordings will become available in the near future.

Housing of pigs in barren, stimulus-poor housing conditions may influence their immune status, including antibody responses to (auto-)antigens, and thus affect immune protection, which will influence the onset and outcome of infection. In the present study, we investigated the effects of environmental enrichment versus barren housing on the level of natural (auto-)antibodies (NA(A)b) and their isotypes (IgM and IgG) binding keyhole limpet hemocyanin (KLH), myelin basic protein (MBP), and phosphorycholine conjugated to bovine serum albumin (PC-BSA) in pigs co-infected with porcine reproductive and respiratory syndrome virus (PRRSV) and Actinobacillus pleuropneumoniae ( A. pleuropneumoniae ). Pigs ( n  = 56) were housed in either barren or enriched pens from birth to 54 days of age. They were infected with PRRSV on 44 days of age, and with A. pleuropneumoniae 8 days later. Blood samples were taken on 7 different sampling days. Housing significantly affected the overall serum levels of NA(A)b binding KLH, MBP and PC-BSA, and before infection barren housed pigs had significantly higher levels of NA(A)b than enriched housed pigs, except for KLH-IgM and PC-BSA-IgG. Infection only affected the IgM, but not the IgG isotype. Moreover, changes in MBP-IgM and PC-BSA-IgM following infection were different for enriched and barren housed pigs. These results suggest that the effect of infection on NA(A)b is influenced by housing conditions and that NA(A)b, especially IgM may be affected by infection.

Exposure to CO2 at high concentration is a much debated stunning method in pigs. Pigs respond aversively to high concentrations of CO2, and there is uncertainty about what behaviors occur before and after loss of consciousness. The aim was to assess timing of unconsciousness in pigs during exposure to high concentrations of CO2 based on changes in electroencephalogram (EEG) activity and the relation with the behaviors sniffing, retreat and escape attempts, lateral head movements, jumping, muscular contractions, loss of posture, and gasping. Pigs (108 ± 9 kg) were randomly assigned to 80% CO2 (80C, n = 24) or 95% CO2 (95C, n = 24). The time at which the gondola started descending into the well pre-filled with 80C or 95C was marked as T = 0. The CO2 exposure lasted 346 s after which the corneal reflex and breathing were assessed for 1 min. Visual assessment of changes in the amplitude and frequency of EEG traces after T = 0 was used to determine loss of consciousness. Time to loss of consciousness was longer in 80C pigs (47 ± 6 s) than in 95C pigs (33 ± 7 s). Time to an iso-electric EEG was similar in 80C pigs (75 ± 23 s) and 95C pigs (64 ± 32 s). When pigs descended into the well, the earlier entry of 95C pigs into high CO2 atmosphere rather than the concentration of CO2 by itself affected the latency of behavioral responses and decreasing brain activity. During exposure to the gas, 80C and 95C pigs exhibited sniffing, retreat attempts, lateral head movements, jumping, and gasping before loss of consciousness. 95C pigs exhibited all these behaviors on average earlier than 80C pigs after T = 0. But the interval between onset of these behaviors and loss of consciousness and the duration of these behaviors, except gasping, was similar for both treatments. Loss of posture was on average observed in both groups 10 s before EEG-based loss of consciousness. Furthermore, 88% of 80C pigs and 94% of 95C pigs demonstrated muscular contractions before loss of consciousness. The findings provide little reason to conclude on a behavioral basis that these atmospheres are greatly different in their impact on pig welfare.

The European Union (EU) Broiler Directive (2007/43/EC) is unique amongst current EU Directives, which address animal welfare, in that it uses outcome data collected at abattoirs and on farm to monitor on-farm broiler welfare and vary the maximum permitted stocking density on farm. In this study, we describe how, by bringing together personnel from the competent authorities in 22 member states (MSs) who have responsibility for implementing the Directive, and engaging in exchange of information and technical methods regarding the Broiler Directive, it has been possible to identify differences in approach with regard to ‘what data is being collected, and by whom’ across EU MSs. Online questionnaires and workshop exercises enabled us to identify priority areas for knowledge transfer and training. For example, foot pad dermatitis, hock burn, dead on arrival and total rejections (birds rejected as unfit for human consumption by the meat inspection staff at slaughter) were identified by the MSs as measures of medium-to-low priority in terms of knowledge transfer because there are assessment methods for these conditions that are already well accepted by competent authorities. On the other hand, breast lesions, cellulitis, emaciation, joint lesions, respiratory problems, scratches, wing fractures and a number of environmental measures were identified as having high priority in terms of knowledge transfer. The study identified that there is significant variability in the stage of implementation between MSs, and responses from the participating MSs indicated that sharing of guidance and technical information between MSs may be of value in the future set-up process for those MSs engaged in implementation of the Directive.

At present there is limited understanding of the host immune response to (low pathogenic) avian influenza virus infections in poultry. Here we develop a mathematical model for the innate immune response to avian influenza virus in chicken lung, describing the dynamics of viral load, interferon-α, -β and -γ, lung (i.e. pulmonary) cells and Natural Killer cells. We use recent results from experimentally infected chickens to validate some of the model predictions. The model includes an initial exponential increase of the viral load, which we show to be consistent with experimental data. Using this exponential growth model we show that the duration until a given viral load is reached in experiments with different inoculation doses is consistent with a model assuming a linear relationship between initial viral load and inoculation dose. Subsequent to the exponential-growth phase, the model results show a decline in viral load caused by both target-cell limitation as well as the innate immune response. The model results suggest that the temporal viral load pattern in the lungs displayed in experimental data cannot be explained by target-cell limitation alone. For biologically plausible parameter values the model is able to qualitatively match to data on viral load in chicken lungs up until approximately 4 days post infection. Comparison of model predictions with data on CD107-mediated degranulation of Natural Killer cells yields some discrepancy also for earlier days post infection.