[Show abstract][Hide abstract] ABSTRACT: In birds there is compelling evidence that the development and expression of behavior is affected by maternal factors, particularly via variation in yolk hormone concentrations of maternal origin. In the present study we tested whether variation in yolk hormone levels lead to variation in the expression of neophobia in young domestic chicks. Understanding how the prenatal environment could predispose chicks to express fear-related behaviors is essential in order to propose preventive actions and improve animal welfare. We simulated the consequences of a maternal stress by experimentally enhancing yolk progesterone, testosterone and estradiol concentrations in hen eggs prior to incubation. The chicks from these hormone-treated eggs (H) and from sham embryos (C) that received the vehicle-only were exposed to novel food, novel object and novel environment tests. H chicks approached a novel object significantly faster and were significantly more active in a novel environment than controls, suggesting less fearfulness. Conversely, no effect of the treatment was found in food neophobia tests. Our study highlights a developmental influence of yolk hormones on a specific aspect of neophobia. The results suggest that increased yolk hormone levels modulate specifically the probability of exploring novel environments or novel objects in the environment.
[Show abstract][Hide abstract] ABSTRACT: Furnished cages for laying hens exist in a wide variety of sizes and designs and should be equipped to allow hens to express some of their behavioural priorities. European Council Directive 1999/74/EC stipulates that litter must be provided for pecking and scratching but the type of litter and the pad where litter is delivered are not defined. In the same way, neither the maximum nor the optimum number of birds per cage has been defined. Two successive experiments were carried out to analyse pecking, scratching (PS) and dustbathing (DB) behaviours performed in different furnished cages with different designs. Three group sizes of ISA brown laying hens (20, 40 or 60 hens, with the same density in all the cages), with or without additional feed distribution as litter substrate, were compared in the first experiment. The second experiment focussed on DB behaviour and compared two pecking and scratching pads (artificial turf or rubber mats), with or without wheat bran distribution as litter substrate, in groups of 60 hens per cage. Irrespective of litter presence, group size, and type of pad, DB and PS were mainly performed in the pecking and scratching area, showing the attractiveness of this area. In the first experiment, feed–litter provision in pecking and scratching area increased PS and DB behaviours, while group size did not affect them. In the second experiment, hens performed more DB in the pecking and scratching area when wheat-bran litter was present than when it was absent. Rubber matting was more attractive to hens for DB than artificial turf matting. Durations of DB bouts were not affected by the presence or absence of wheat-bran litter or the choice of pecking and scratching pad. In furnished cages, hens clearly seek out pads and litter to perform PS, and providing litter (feed or wheat bran) or rubber in pecking and scratching area is attractive for hens to DB in it. However, the cage design could be improved to promote more DB activity, for instance by increasing space of pecking and scratching area in the cage.
[Show abstract][Hide abstract] ABSTRACT: Detecting genomic footprints of selection is an important step in the
understanding of evolution. Accounting for linkage disequilibrium in genome
scans allows increasing the detection power, but haplotype-based methods
require individual genotypes and are not applicable on pool-sequenced samples.
We propose to take advantage of the local score approach to account for linkage
disequilibrium, accumulating (possibly small) signals from single markers over
a genomic segment, to clearly pinpoint a selection signal, avoiding windowing
methods. This method provided results similar to haplotype-based methods on two
benchmark data sets with individual genotypes. Results obtained for a divergent
selection experiment on behavior in quail, where two lines were sequenced in
pools, are precise and biologically coherent, while competing methods failed:
our approach led to the detection of signals involving genes known to act on
social responsiveness or autistic traits. This local score approach is general
and can be applied to other genome-wide analyzes such as GWAS or genome scans
[Show abstract][Hide abstract] ABSTRACT: Background
Behavioral traits such as sociability, emotional reactivity and aggressiveness are major factors in animal adaptation to breeding conditions. In order to investigate the genetic control of these traits as well as their relationships with production traits, a study was undertaken on a large second generation cross (F2) between two lines of Japanese Quail divergently selected on their social reinstatement behavior. All the birds were measured for several social behaviors (social reinstatement, response to social isolation, sexual motivation, aggression), behaviors measuring the emotional reactivity of the birds (reaction to an unknown object, tonic immobility reaction), and production traits (body weight and egg production).ResultsWe report the results of the first genome-wide QTL detection based on a medium density SNP panel obtained from whole genome sequencing of a pool of individuals from each divergent line. A genetic map was constructed using 2145 markers among which 1479 could be positioned on 28 different linkage groups. The sex-averaged linkage map spanned a total of 3057 cM with an average marker spacing of 2.1 cM. With the exception of a few regions, the marker order was the same in Japanese Quail and the chicken, which confirmed a well conserved synteny between the two species. The linkage analyses performed using QTLMAP software revealed a total of 45 QTL related either to behavioral (23) or production (22) traits. The most numerous QTL (15) concerned social motivation traits. Interestingly, our results pinpointed putative pleiotropic regions which controlled emotional reactivity and body-weight of birds (on CJA5 and CJA8) or their social motivation and the onset of egg laying (on CJA19).Conclusion
This study identified several QTL regions for social and emotional behaviors in the Quail. Further research will be needed to refine the QTL and confirm or refute the role of candidate genes, which were suggested by bioinformatics analysis. It can be hoped that the identification of genes and polymorphisms related to behavioral traits in the quail will have further applications for other poultry species (especially the chicken) and will contribute to solving animal welfare issues in poultry production.
[Show abstract][Hide abstract] ABSTRACT: It has long been known that stress during the slaughter period may result in the production of meat with major quality defects, particularly exudative and dark-cutting meat. Recent studies using behavioural, physiological and/or genomic approaches found that less extreme stress levels during slaughter may also influence technological and/or sensory qualites of meat from pigs, cattle, sheep, poultry and fish flesh, sometimes explaining over 70% of inter-animal variability in quality. Stress reactivity at slaughter varies between individuals and may be predicted from their reactions to stressful challenges during the rearing period. The stress reactivity of an animal depends partly on its earlier experiences and genetic background. In addition to slaughter-related animal welfare questions, today's challenge is to increase our understanding of the physiological and molecular mechanisms underlying the effects of stress on meat quality. The different species should be taken into account, as the causes of stress at slaughter and criteria for optimal meat quality are species-specific. In addition, the biological mechanisms underlying the effect of stress on meat and flesh quality partly differ between species.
Full-text · Article · Jan 2015 · Productions Animales -Paris- Institut National de la Recherche Agronomique-
[Show abstract][Hide abstract] ABSTRACT: It has long been known that stress during the slaughter period may result in the production of meat with major quality defects,particularly exudative and dark-cutting meat. Recent studies using behavioural, physiological and/or genomic approaches found thatless extreme stress levels during slaughter may also influence technological and/or sensory qualites of meat from pigs, cattle, sheep,poultry and fish flesh, sometimes explaining over 70% of inter-animal variability in quality. Stress reactivity at slaughter variesbetween individuals and may be predicted from their reactions to stressful challenges during the rearing period. The stress reactivityof an animal depends partly on its earlier experiences and genetic background. In addition to slaughter-related animal welfarequestions, today’s challenge is to increase our understanding of the physiological and molecular mechanisms underlying the effectsof stress on meat quality. The different species should be taken into account, as the causes of stress at slaughter and criteria for optimalmeat quality are species-specific. In addition, the biological mechanisms underlying the effect of stress on meat and flesh quality partlydiffer between species.
[Show abstract][Hide abstract] ABSTRACT: Animals perceiving repeated aversive events can become chronically stressed. Chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis can have deleterious consequences on physiological parameters (e.g. BW, blood chemistry) and behaviour (e.g. emotional reactivity, stereotypies, cognition). Environmental enrichment (EE) can be a mean to reduce animal stress and to improve welfare. The aim of this study was first, to assess the effects of EE in battery cages on the behaviour of young Japanese quail and second, to evaluate the impact of EE on quail exposed to chronic stress. The experiment involved quail housed in EE cages and submitted or not to a chronic stress procedure (CSP) (EE cages, control quail: n=16, CSP quail: n=14) and quail housed in standard cages and exposed or not to the CSP (standard non-EE cages, control quail: n=12, CSP quail: n=16). Our procedure consisted of repeated aversive events (e.g. ventilators, delaying access to food, physical restraint, noise) presented two to five times per 24 h, randomly, for 15 days. During CSP, EE improved quail's welfare as their stereotypic pacing decreased and they rested more. CSP decreased exploration in all quail. After the end of CSP, quail presented increased emotional reactivity in emergence test. However, the effect of EE varied with test. Finally, chronic stress effects on comfort behaviours in the emergence test were alleviated by EE. These results indicate that EE can alleviate some aspects of behavioural alterations induced by CSP.
[Show abstract][Hide abstract] ABSTRACT: Since 2012 in the EU, cages for the housing of laying hens must provide nests, perches and a pecking and scratching area to promote natural behaviours and enhance animal welfare. Previous studies highlighted the difficulty of finding adequate materials for pecking and scratching areas in such cages, mainly due to hygiene problems and technical constraints. This study investigates whether alternative materials could stimulate dustbathing (DB), pecking, and scratching behaviours and examines if hens show any preferences for these materials compared to other well-known litter materials such as sand, peat and artificial turf. We set up two separate experiments: one to simultaneously compare four litter materials (wheat bran, sand, shell sand and peat) and one to simultaneously compare four alternative non-litter, pad-type solutions (plastic mat, artificial turf mat, a slightly friable experimental block made of wood and oyster shells, and a slightly friable experimental sand block). For each experiment, 15 groups of four hens were observed over four days in a multiple choice test. Wheat bran was found to promote pecking and scratching behaviours better than the other litters. Peat induced more dustbaths than wheat bran but duration of DB bouts was similar for both materials. However, the number of dustbaths in wheat bran increased throughout the test, while the duration of DB bouts decreased in peat, showing an increasing preference for wheat bran. The shell sand was found to be the least preferred for pecking, scratching and DB. In the second experiment, pads were found to be less attractive than litters for pecking, scratching, and DB. The plastic mat was very rarely used for DB compared to other solutions in the pad choice test. As hens rarely pecked or scratched any of the pads, no significant differences were noted between the four different types. However, experimental blocks stimulate DB as much as artificial turf mats and seem promising, as their use for DB increased throughout the test. This study shows that wheat bran could be an optimal litter for use in furnished cages to improve hen welfare. In addition, research on new experimental blocks is worth being developed, as it has the advantage of not needing to be renewed during a laying period.
[Show abstract][Hide abstract] ABSTRACT: Numerous aversive events occur in poultry production, and if repeated and unpredictable, can result in an impaired welfare. Some events such as handling can be perceived negatively and it is of interest to understand how humans' behaviour could affect poultry's behaviours and especially its avoidance of humans. Our aim was to evaluate short- and long-lasting effects of a 3-week procedure involving unpredictable repeated negative stimuli (URNS) applied during the post-juvenile period on quail's reactivity to humans. We compared the reactions of two sets of quail: URNS was applied to one set (treated quail) and the other set was left undisturbed (control quail). When two weeks old, treated quail were exposed to a variety of negative stimuli, either applied automatically or involving human presence. One and seven weeks after the termination of the procedure, the reactivity of control and treated quail to a passive human being was evaluated. Furthermore, the experimenter with her hand on a trough containing a mealworm assessed the propensity of quail of both groups to habituate to feed close to a human being. In the presence of a seated observer, treated quail were more inhibited and more alert than control quail. Likewise, seven weeks after the end of the URNS procedure, more treated than control quail adopted a fear posture. Moreover, whereas control quail spent as much time in the different areas of their cages, treated quail spent more time in the rear part of their cages. Finally, whereas control quail habituated gradually to feed near the experimenter's hand, treated quail did not. All these tests evidence negative short- and long-term effects on treated quail's reactivity to a passive human being and on their habituation to a human being when her presence is positively reinforced. This highlights the importance of young poultry's experience with humans in production.
[Show abstract][Hide abstract] ABSTRACT: Chronic stress is a long-lasting negative emotional state that induces negative consequences on animals' psycho-physiological state. This study aimed at assessing whether unpredictable and repeated negative stimuli (URNS) influence feeding behaviour in quail. Sixty-four quail were exposed to URNS from day 17 to 40, while 64 quail were undisturbed. Two lines divergently selected on their inherent emotionality were used to assess the effect of genetic factors on the sensitivity to URNS. All quail were submitted to a sequential feeding procedure (using two diets of different energetic values) which placed them in a contrasting situation. Behavioural tests were performed to assess the emotional reactivity of the two lines. Results confirmed that differences exist between them and that their emotional reactivity was enhanced by URNS. Diet preferences, motivation and daily intake were also measured. URNS did not change the preferences for the hypercaloric diet compared to the hypocaloric diet in choice tests, but they reduced daily intakes in both lines. Motivations for each diet were differently affected by URNS: they decreased the motivation to eat the hypercaloric diet in quail selected for their low inherent fearfulness whereas they increased the motivation to eat the hypocaloric diet in quail selected for their high inherent fearfulness, which suggested a devaluation process in the former and a compensatory behaviour in the later. Growth was furthermore reduced and laying delayed by URNS in both lines. In conclusion, the exposure to URNS induced interesting changes in feeding behaviour added with an increase in emotional reactivity and an alteration of production parameters. This confirms that both lines of quail experienced a chronic stress state. However differences in feed motivation and emotional reactivity between lines under chronic stress suggested that they experienced different emotional state and use different ways to cope with it depending on their genetic background.
[Show abstract][Hide abstract] ABSTRACT: The social behavior of animals, which is partially controlled by genetics, is one of the factors involved in their adaptation to large breeding groups. To understand better the relationships between different social behaviors, fear behaviors and production traits, we analyzed the phenotypic and genetic correlations of these traits in Japanese quail by a second generation crossing of two lines divergently selected for their social reinstatement behavior. Analyses of results for 900 individuals showed that the phenotypic correlations between behavioral traits were low with the exception of significant correlations between sexual behavior and aggressive pecks both at phenotypic (0.51) and genetic (0.90) levels. Significant positive genetic correlations were observed between emotional reactivity toward a novel object and sexual (0.89) or aggressive (0.63) behaviors. The other genetic correlations were observed mainly between behavioral and production traits. Thus, the level of emotional reactivity, estimated by the duration of tonic immobility, was positively correlated with weight at 17 and 65 days of age (0.76 and 0.79, respectively) and with delayed egg laying onset (0.74). In contrast, a higher level of social reinstatement behavior was associated with an earlier egg laying onset (-0.71). In addition, a strong sexual motivation was correlated with an earlier laying onset (-0.68) and a higher number of eggs laid (0.82). A low level of emotional reactivity toward a novel object and also a higher aggressive behavior were genetically correlated with a higher number of eggs laid (0.61 and 0.58, respectively). These results bring new insights into the complex determinism of social and emotional reactivity behaviors in birds and their relationships with production traits. Furthermore, they highlight the need to combine animal welfare and production traits in selection programs by taking into account traits of sociability and emotional reactivity.
[Show abstract][Hide abstract] ABSTRACT: The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate improvements in the related ABM and thereby enhance the birds' overall welfare status.
[Show abstract][Hide abstract] ABSTRACT: Le bien-être animal est une préoccupation sociétale forte et les animaux de ferme sont reconnus comme étant des êtres sensibles capables de ressentir des émotions. Cependant, les relations entre émotions, réactions affectives transitoires, et bien-être, état affectif persistant, sont mal connues. En outre, malgré des tentatives d’enrichissement du milieu d’élevage, les bénéfices sur le bien-être de l’animal voire sa santé ne sont pas garantis et les déterminants comportementaux restent méconnus. Une approche transdisciplinaire (éthologie, neurophysiologie, psychopharmacologie, immunologie, et neurobiologie) a été conduite entre 2009 et 2012 sur ovins et cailles, en tant qu’espèces cibles et modèles.
[Show abstract][Hide abstract] ABSTRACT: Poultry production will have to be increased in the future to meet the demands of the growing human population. This will increase the pressure on land use to produce cereals and proteins used in poultry diets and also the environmental pressure due to the increase of manure produced by these birds. Selecting birds able to digest more varied and less optimal diets could be a way to minimize these negative impacts of poultry production. Selection for digestive efficiency using a diet difficult to digest has been shown to be efficient to increase the proportion of poor quality feedstuffs in the diet. In this study, to prevent negative effects that could occur on non-selected traits, we evaluate the impact of this selection on a wide range of traits related to the economic, social and environmental pillars of sustainability. This was achieved on 846 chickens issued from selection for high (D+) or low (D-) digestive efficiency fed either a classical corn+soybean diet or an alternative wheat+sunflower meal diet. Multifactorial correspondence analyses were realized on each pillar of sustainability. For the economic pillar, we recorded growth, feed consumption, feed efficiency, digestibility of phosphorus, anatomy of the digestive tract, and meat quality. For the environmental pillar, we recorded quantity of litter and temperature, humidity, nitrogen, and ammonia and phosphorus content of the litter. For the social pillar, we measured normal animal behavior, presence of dermatitis, bone yield and mineralization and susceptibility to coccidiosis and to colibacillosis. Our results showed that 1) the D+ birds have a positive impact on economic and environmental traits, with better efficiency, lower consumption, and less manure production; 2) the two lines were not different on behavior and health traits, apart from a better bone yield in D+ line and 3) the D- birds were more sensitive to the diet than D+ birds.