Campylobacter spp. are leading bacterial gastroenteritis pathogens. Infections are largely underreported, and the burden of outbreaks may be underestimated. Current strategies of testing as few as one isolate per sample can affect attribution of cases to epidemiologically important sources with high Campylobacter diversity, such as chicken meat. Multiple culture method combinations were utilized to recover and sequence Campylobacter from 45 retail chicken samples purchased across Norwich, UK, selecting up to 48 isolates per sample. Simulations based on resampling were used to assess the impact of Campylobacter sequence type (ST) diversity on outbreak detection. Campylobacter was recovered from 39 samples (87%), although only one sample was positive through all broth, temperature, and plate combinations. Three species were identified (Campylobacter jejuni, Campylobacter coli, and Campylobacter lari), and 33% of samples contained two species. Positive samples contained 1–8 STs. Simulation revealed that up to 87 isolates per sample would be required to detect 95% of the observed ST diversity, and 26 isolates would be required for the average probability of detecting a random theoretical outbreak ST to reach 95%. An optimized culture approach and selecting multiple isolates per sample are essential for more complete Campylobacter recovery to support outbreak investigation and source attribution.

The profitability of U.S. meat producers and the utility of U.S. meat consumers are impacted by the trade of meat. USDA publishes the most prominent publicly available meat trade projections. This study finds USDA projections typically underpredict meat export volumes and overpredict meat import volumes. USDA projections outperform naïve projections for beef and pork exports, but naïve projections at times outperform USDA projections for chicken exports and beef and pork imports, especially at shorter horizons. USDA projections exclude variety cuts, which comprise a sizeable share of beef and pork exports. There remains room for improvement in projecting U.S. meat trade.

The effectiveness of electrical water bath stunning of broilers (n = 96) for 1 s with a constant average current of 100, 150 or 200 mA delivered using a variable voltage/constant current stunner with 200, 800 or 1400 Hz pulsed direct current (DC), with a mark:space ratio of 1:1, followed by slaughter using a unilateral or ventral neck cutting procedure, was evaluated. The results of a binary logistic model showed that both the electrical frequency and average current had significant effects on the probability of inducing epileptiform electroencephalogram (EEG) and therefore, of effective stunning. The results of univariate analysis showed that only slaughter method had highly significant effects on the power contents in the 13–30 Hz and 2–30 Hz EEG frequency bands. Based on these results, it is recommended that a minimum of 200 mA average (400 mA peak) current per bird should be delivered using 200 Hz pulsed DC, with a mark:space ratio of 1:1, to achieve effective water bath stunning in 80% of broilers. Frequencies of above 200 Hz pulsed DC would presumably require average currents of greater than 200 mA. Electrical water bath stunning of broilers with 200 mA average current of 200 Hz resulted in cardiac arrest in six out of eight broilers that showed epileptiform activity. Two other broilers that had cardiac arrest showed no epileptiform EEGs indicative of effective stunning. Owing to the prevalence of cardiac arrest in conscious broilers, the use of pulsed DC for water bath stunning of broilers could be questioned on ethical and bird welfare grounds.

In humans, psychological manipulations such as hypnosis, behavioural modifications, relaxation training and cognitive behaviour therapy have all been used to reduce pain intensity. One thing these treatments have in common is selective attention. Work on attention-based cognitive coping strategies has shown that they have potentially useful analgesic qualities in pain therapy. In animals, there have been few studies on the effects of attentional shifts on pain perception. There is extensive literature on stress-induced analgesia and it is likely that, in some of the experiments, attention could be an important variable. This paper will present some of our recent work on selective attention and pain perception using the sodium urate model of gouty arthritis. Birds are naturally prone to articular gout and the model we have developed mimics acute gouty attacks in a single joint. Experimental sodium urate arthritis produces a tonically painful inflammation lasting for at least 3h during which time the animals show pain-related behaviours. Changes in motivation can reduce these pain-related behaviours and it has been hypothesized that these motivational changes act by way of altering the attention of the animal away from pain. The motivational changes investigated included nesting, feeding, exploration and social interactions. The degree of pain suppression ranged from marked hypoalgesia to complete analgesia and as such demonstrates a remarkable ability to suppress tonic pain. These shifts in attention not only reduced pain but also significantly reduced peripheral inflammation. These results are discussed in terms of the limited capacity models of attention.

The effect of the pulse width of a direct current (DC) on the effectiveness of electrical water bath stunning, and slaughter, was evaluated in broilers (n = 29). Broilers were individually stunned in a water bath for 1 s with a constant peak current of 400 mA of 200 Hz DC delivered using a variable voltage/constant current stunner. The pulse width of the 200 Hz DC was set at 0.5, 1.5 or 2.5 ms (10, 30 or 50% of 5 ms current cycle). The results showed that pulse width had a significant effect on the incidence of epileptiform activity in the electroencephalograms (EEGs). A pulse width of 10% of the current cycle was less effective than pulse widths of 30 and 50% of the current cycle; there was no significant difference between a pulse width of 30 and 50%. The results of a univariate analysis showed that ventral neck-cutting resulted in a significantly shorter time to the onset of less than 10% of the pre-stun power contents in the 13–30 Hz and 2–30 Hz EEG frequency bands when compared with unilateral neck-cutting. It is concluded that a pulse width of 30 or 50% of the current cycle of 200 Hz DC, delivering 400 mA peak current, was better than using a pulse width of 10% of the current cycle.

The effectiveness of head-only electrical stunning of broilers, with a root mean square (RMS) current of 100 or 150mA delivered using either 50, 400 or 1500Hz sine wave alternating current (AC), was investigated. The changes occurring in the spontaneous electroencephalogram (EEG) were evaluated using Fast Fourier Transformations (FFT) to determine the impact of the amount and frequency of stunning current on total (2-30 Hz) and relative (13-30 Hz) power contents in the EEG. Induction of epileptiform activity and reduction in the EEG power contents to less than 10% of pre-stun levels from the end of epileptiform activity were used as indicators of effective stunning. The duration of unconsciousness and insensibility was determined on the basis of the return of EEG power contents. In addition, the changes occurring in somatosensory evoked potentials (SEPs) were subjectively evaluated to determine the impact of stunning treatments. The results of ANOVA (repeated measures) showed statistically significant effects of interactions between the current frequencies, amount of current and repeated measures on changes in EEG power contents (P < 0.001). Stunning broilers with 150 mA delivered using 50 Hz resulted in EEG changes that were indicative of more pronounced neuronal inhibition following epileptiform activity and also lasted longer than was the case when broilers were stunned with 150 mA delivered using 400 Hz. Stunning broilers with 100 mA delivered using 50 Hz resulted in changes very similar to those observed after stunning with 150 mA of 50 Hz, but which lasted for a relatively shorter time. However, these changes were more pronounced and lasted longer than did stunning with 100 mA delivered using 400 Hz. The effects of stunning broilers with 150 mA of 400 Hz were similar to those found after stunning with 100 mA of 50 Hz. By contrast, stunning broilers with 100 mA of 1500 Hz failed to fulfil the criteria set out in this study. Stunning of broilers with 150 mA of 1500 Hz induced epileptiform activity but failed to reduce EEG power contents to less than 10% of pre-stun levels. Therefore, the stunning of broilers with 100 or 150 mA of 1500 Hz may not be adequate to avoid pain and suffering during slaughter. Thus, minimum currents of 100, 150 and 200 mA should be delivered whilst using 50, 400 and 1500 Hz, respectively, to achieve effective electrical stunning in broilers. Severing of the carotid arteries in the neck following head-only electrical stunning, and high frequency (> 125 Hz) electrical water bath stunning of broilers should also become a statutory requirement to prevent the return of consciousness during bleeding.

Bodily contact with water is a novel and aversive experience for broiler chickens, and this has been used when designing the Latency to Lie (LTL) test. The original testing procedure, in which the birds are tested in groups, involves a certain settling period, which makes the test time-consuming to carry out on commercial broiler farms. Our modifications of the LTL test for on-farm use mean that a) the birds are tested individually without visual contact with other birds; and b) the water tub is already filled with water when the birds are placed in it. The results from the LTL tests can then be compared with the scores achieved for each individual bird on the commonly used ‘gait scoring’ procedure. At 14 farms participating in a larger survey, we used three birds of each gait score from 0 to 4 (when available) for LTL testing. The time spent standing before making the first attempt to lie down was recorded. The results show a clear negative correlation (r = -0.86, P < 0.001) between time spent standing and gait score. The mean LTL values for the different gait scores were all significantly (P < 0.01) different. There was no significant difference in LTL results between flocks. The method described appears to be well suited for on-farm use. If further developed, it could become a useful tool in monitoring programmes for the ongoing efforts aiming at decreasing the levels of leg weakness in modern broiler production.

Frequent diet change has been identified as a risk factor for feather pecking in commercial flocks but the mechanism underlying this association is not known. In this experiment we simulated a commercial change of diet between high quality (HQ) 19% protein, and low quality (LQ) 15% protein, diets. Twelve pairs of birds were fed both diets simultaneously for 38 days to determine whether clear preferences for the diets existed. A further 12 triplets of birds were fed either HQ or LQ diets for 38 days to examine any absolute effects of quality on behaviour. The remaining triplets received, on day 29, either a LQ to HQ diet change (n = 12 groups) or an HQ to LQ diet change (n = 12 groups). Half of the groups in these diet change treatments received oregano oil as a potential ‘masking’ agent to disguise the diet change. No dietary preferences were detected and there were no absolute effects of diet on behaviour. Diet change provoked significant increases in beak-related activity. Specifically, affiliative pecking (allopreening directed towards comb or beak) was increased after diet change. Masking the diet reduced the effects of diet change. Injurious pecking remained at low levels throughout the experiment and was not affected by diet change, but the relationship between affiliative pecking and subsequent injurious pecking requires further investigation.

The effectiveness of electrical water bath stunning of 172 individual broilers for 1 s with a constant root mean square (RMS) current of 100, 150 or 200 mA, delivered using a variable voltage/constant current stunner with 200, 400, 600, 800, 1000, 1200 or 1400 Hz sine wave alternating current (AC), followed by slaughter using a unilateral or ventral neck-cutting procedure, was evaluated. A binary logistic regression of broilers showing epileptiform activity or not following stunning showed that both the electrical frequency (Hz) and RMS current (mA) had a significant effect on the probability of the electroencephalogram (EEG) manifestation. The univariate analysis of variance showed that the time to the onset of less than 10% of the pre-stun relative power contents was significantly affected only by the interaction between electrical frequency and slaughter method. A similar analysis of variance of the time to reach less than 10% of the pre-stun total power content showed slaughter method, RMS current, the slaughter method/frequency interaction and the RMS current/frequency interaction to be either significant or approaching significance. Based on these results it is recommended that effective water bath stunning of broilers with a minimum constant current of 100, 150 and 200 mA could be achieved with electrical frequencies of up to 200, 600 and 800 Hz, respectively. In addition, It is likely that electrical frequencies of above 800 Hz would have required a minimum current of greater than 200 mA to induce epileptiform activity in the EEGs of broilers.

Animal welfare assessment commonly involves behavioural and physiological measurements. Physiological measures have become increasingly sophisticated over the years, while behavioural measurements, for example duration or frequency, have changed little. Although these measures can undoubtedly contribute to our assessment of an animal's welfare status, a more complex analysis of behavioural sequences could potentially reveal additional and valuable information. One emerging methodology that could provide such information is fractal analysis, which calculates measures of complexity in continuous time series. Its previous application in medical physiology suggested that it could reveal ‘hidden’ information in a dataset beyond that identified by traditional analyses. Consequently, we asked if fractal analysis of behaviour might be a useful non-invasive measure of acute and chronic stress in laying hens and in pigs. Herein, we outline our work and briefly review some previous applications of fractal analysis to animal behaviour patterns. We successfully measured novel aspects of complexity in the behavioural organisation of hens and pigs and found that these were stress-sensitive in some circumstances. Although data collection is time consuming, the benefit of fractal analysis is that it can be applied to simple behavioural transitions, thereby reducing subjective interpretation to a minimum. Collectively, the work to date suggests that fractal analysis — by providing a novel measure of behavioural organisation — could have a role in animal welfare assessment. As a method for extracting extra information from behavioural data, fractal analysis should be more widely examined in animal welfare science.

Regarding broilers, Brazil is the third largest producer and the leading chicken meat exporter in the world. Independent certifications are required by some importers in the European Union (EU) to guarantee compliance with minimum welfare requirements. Our objective was to compare broiler chicken welfare in GLOBALGAP® certified (C) and non-certified (N) intensive farms in the State of Paraná, Brazil, using the Welfare Quality® protocol. Ten farms in each group were evaluated and data were transformed using scores that ranged from 0 to 100, where 100 is the best condition. Results suggested that farms adhered to minimum welfare standards, regardless of certification and that the adoption of standards based on overseas rules may have limitations for the improvement of animal welfare. In order to further improve broiler welfare in Brazil, more rigorous standards should be developed.

Increased production has been the major goal of animal breeding for many decades, and the correlated side-effects have grown to become a major issue in animal welfare. In this paper, the main genetic mechanisms in which such side-effects may occur are reviewed with examples from our own research in chickens. Pleiotropy, linkage and regulatory pathways are the most important means by which a number of traits may be affected simultaneously by the same selection pressure. Pleiotropy can be exemplified by the gene PMEL17 which causes a lack of black pigmentation in chickens and, simultaneously, predisposes them to become the victims of feather pecking. Linkage is a probable reason why a limited region on chicken chromosome 1 affects many different traits, such as growth, reproduction and fear-related behaviour. Gene regulation is affected by stress, and may cause modifications in behaviour and phenotype which are transferred from parents to offspring by means of epigenetic modifications. Insights into phenomena, such as these, may increase our understanding not only of how artificial selection works, but also evolution at large.

Broiler breeder chickens are commonly reared under strict feed-restriction regimes to reduce obesity-induced health and fertility problems during adult life, and are assumed to experience a reduced welfare due to the resulting hunger. In these conditions, feed competition could influence the growth rate, so that the individuals falling behind in growth would experience more stress and hunger. We hypothesised that these chickens are poor competitors due to a reactive coping style and experience a further reduced welfare situation before size-sorting (‘grading’) at four weeks of age. Our results from open field, tonic immobility and home pen activity monitoring show signs of lower fear and higher home-pen activity levels in smaller hens and do not support the idea of reactive coping. H/L ratios of smaller hens were also found to be lower, indicating less stress in these birds. Dissections of smaller and larger four-week breeder hens may offer an explanation in the form of a relatively larger gastrointestinal tract in smaller birds. We argue that this is a form of habituation to restricted feeding, offering these birds a physiological stress coping mechanism, and that low early growth rate may not always be a sign of poorer welfare in broiler breeders.

Severe feather pecking, a potentially stereotypic behaviour in chickens (Gallus gallus), can be reduced by providing enrichment. However, there is little comparative information available on the effectiveness of different types of enrichment. Providing forages to birds is likely to decrease feather-pecking behaviour the most, as it is generally thought that feather pecking stems from re-directed foraging motivation. Yet, other types of enrichment, such as dustbaths and novel objects, have also been shown to reduce feather pecking. In order to develop a practical and effective enrichment, these different possibilities must be examined. Using a Latin Square Design, 14-week old birds were given each of four treatments: i) forages; ii) novel objects; iii) dustbaths; or iv) no enrichment. The amount of feather-pecking behaviour and the number of pecks to the enrichments were recorded. Results showed feather pecking to be highest when no enrichment was present and lowest when the forages were present, with the other two enrichments intermediate. This was despite the fact that the numbers of pecks birds gave to the forages and dustbaths were not significantly different, suggesting that they were similarly used. Thus, we suggest here that forage enrichments are most effective at alleviating feather pecking at least in the short term and attempts should be made to develop poultry housing that allows for natural foraging behaviour. Following this, providing any kind of enrichment will increase bird welfare and is therefore still beneficial.

To investigate methods for in vitro assessment of anthelmintic efficacy against the chicken nematode Ascaridia galli this study firstly evaluated sample preparation methods including recovery of eggs from excreta using different flotation fluids and induced larval hatching by the deshelling–centrifugation method and the glass-bead method with or without bile. It then evaluated two in vitro assays, the in-ovo larval development assay (LDA) and larval migration inhibition assay (LMIA), for anthelmintic efficacy testing against A. galli using fresh eggs and artificially hatched larvae, respectively. Four anthelmintics, thiabendazole (TBZ), fenbendazole (FBZ), levamisole (LEV) and piperazine (PIP) were employed using an A. galli isolate of known susceptibility. The results suggested that the LDA and LMIA could successfully be used to generate concentration response curves for the tested drugs. The LDA provided EC50 values for inhibition of egg embryonation of 0.084 and 0.071 μg/ml for TBZ and FBZ, respectively. In the LMIA, the values of effective concentration (EC50) of TBZ, FBZ, LEV and PIP were 105.9, 6.32, 349.9 and 6.78 × 107 nM, respectively. For such in vitro studies, a saturated sugar solution showed high egg recovery efficiency (67.8%) and yielded eggs of the highest morphological quality (98.1%) and subsequent developmental ability (93.3%). The larval hatching assays evaluated did not differ in hatching efficiency but the deshelling–centrifugation method yielded larvae that had slightly better survival rates. For final standardization of these tests and establishment of EC50 reference values, tests using isolates of A. galli of defined resistance status need to be performed.

Plant-based proteins are considered to be less effective in their capacity to stimulate muscle protein synthesis when compared with animal-based protein sources, likely due to differences in amino acid contents. We compared the postprandial muscle protein synthetic response following the ingestion of a lysine-enriched plant-based protein product with an isonitrogenous amount of chicken. Twenty-four men (age 24 ± 5 years; BMI 22·9 ± 2·6 kg·m−2) participated in this parallel, double-blind, randomised controlled trial and consumed 40 g of protein as a lysine-enriched wheat and chickpea protein product (Plant, n 12) or chicken breast fillet (Chicken, n 12). Primed, continuous intravenous l-(ring-13C6)-phenylalanine infusions were applied while repeated blood and muscle samples were collected over a 5-h postprandial period to assess plasma amino acid responses, muscle protein synthesis rates and muscle anabolic signalling responses. Postprandial plasma leucine and essential amino acid concentrations were higher following Chicken (P < 0·001), while plasma lysine concentrations were higher throughout in Plant (P < 0·001). Total plasma amino acid concentrations did not differ between interventions (P = 0·181). Ingestion of both Plant and Chicken increased muscle protein synthesis rates from post-absorptive: 0·031 ± 0·011 and 0·031 ± 0·013 to postprandial: 0·046 ± 0·010 and 0·055 ± 0·015 % h−1, respectively (P-time < 0·001), with no differences between Plant and Chicken (time x treatment P = 0·068). Ingestion of 40 g of protein in the form of a lysine-enriched plant-based protein product increases muscle protein synthesis rates to a similar extent as an isonitrogenous amount of chicken in healthy, young men. Plant-based protein products sold as meat replacers may be as effective as animal-based protein sources to stimulate postprandial muscle protein synthesis rates in healthy, young individuals.

This study explores the effects of consumers’ beliefs about labels on chicken. We elicit beliefs associated with seven different labels. By varying the presence/absence of labels in a choice experiment, we are able to determine the effects of labels on consumer choices and decompose the value of labels into beliefs and base utility. Health perceptions have the largest positive effect, and impacts of animal welfare vary by information treatment. We explore the convergent validity of our approach by comparing individual’s beliefs to responses to a best-worst scaling question, which were weakly correlated, suggesting the two approaches are measuring different constructs.

I analyze institutions of prison subculture that mitigate potential violent confrontations among inmates, in contrast to Hobbesian-Zimbardo default spontaneous violence. The games that are relatively rarely played in prison are Chicken and other violent confrontation games. Incoming rookie inmates are subject to initiation tests that allocate them into different subcultural groups, which signals their toughness and disincentivizes fighting. Most experienced inmates develop the eristic skills utilizing prison argot, use informal conflict adjudicators, and fake aggression toward rookies. All inmates form defensive coalitions. Finally, when inmates commit self-injuries, they follow well-rehearsed protocols to minimize the damage to their bodies and to maximize the impression made on the authorities. The secret knowledge of the associated rules, tricks, and cons is passed down over generations of prisoners through informal schooling. The material for this study comes from two Polish prisons, where the author spent 5 months as a political prisoner in 1985.

The study aimed to monitor parasite and host gene expression during the early stages of Eimeria tenella infection of chicken cells using dual RNA-Seq analysis. For this, we used chicken macrophage-like cell line HD11 cultures infected in vitro with purified E. tenella sporozoites. Cultures were harvested between 2 and 72 h post-infection and mRNA was extracted and sequenced. Dual RNA-Seq analysis showed clear patterns of altered expression for both parasite and host genes during infection. For example, genes in the chicken immune system showed upregulation early (2–4 h), a strong downregulation of genes across the immune system at 24 h and a repetition of early patterns at 72 h, indicating that invasion by a second generation of parasites was occurring. The observed downregulation may be due to immune self-regulation or to immune evasive mechanisms exerted by E. tenella. Results also suggested pathogen recognition receptors involved in E. tenella innate recognition, MRC2, TLR15 and NLRC5 and showed distinct chemokine and cytokine induction patterns. Moreover, the expression of several functional categories of Eimeria genes, such as rhoptry kinase genes and microneme genes, were also examined, showing distinctive differences which were expressed in sporozoites and merozoites.