Social Reinstatement Behaviour Research Articles

Exploring animal genetic resources of the domestic chicken and their behavior in the open field

Animal welfare is of general interest, and in the farming arena, efforts have increased to create optimal conditions for poultry production. Detailed and standardized studies on specific behavioral issues, such as fear, exploration, and social reinstatement behavior, are needed to support these initiatives. The variables mentioned can be directly queried from the animal in the open field to provide information on welfare-related behavioral traits, such as general fearfulness and balanced emotionality. Animal genetic resources help us get an insight into the possible diversity of behavioral responses. The majority of these responses can be identified as breed-specific and thus genetically correlated, providing a starting point for future breeding objectives. The behavioral responses of a chicken can be related to the breeding history of the population or to the experience gained during its lifetime. Both may go hand in hand to enable the animal to adapt to its environment, contributing to animal welfare.

Genetic parameters for bone ash and phosphorus utilization in an F2 cross of Japanese quail

ABSTRACTThe main objective of this study was to perform quantitative genetic analyses of tibia and foot ash traits, which might serve as proxy traits to improve phosphorus utilization (PU) in a breeding program. Additionally, data for ash concentration in tibia and foot were compared with data for total amount of ash. Heritabilities for bone ash traits and genetic and phenotypic correlations between bone ash traits and PU were estimated. A total of 887 F2 birds, established from 2 Japanese quail lines divergently selected on social reinstatement behavior, were provided a P deficient diet. In a metabolic study, feed consumption was measured and total excreta collected for each bird separately. Afterwards, birds were euthanized, the bones obtained and incinerated. Bone ash data showed a heritability of 0.230 (amount of tibia ash) to 0.342 (amount of foot ash), which was higher than estimated for PU, P retention, calcium utilization (0.120–0.174), and performance traits (0.088–0.114). The strongest genetic and phenotypic correlations between PU and bone ash traits were detected for the amount of foot ash with 0.549 and 0.527, respectively. Genetic and phenotypic correlations were stronger between PU and ash amount than between PU and ash percentage, irrespective of bone. Therefore, ash amount was considered a better trait than ash percentage to reflect PU. Strong genetic and phenotypic correlations were detected between the amount of foot and tibia ash (0.887 and 0.901, respectively). Phenotypic and genetic correlations between ash amount and PU or calcium utilization were almost identical, irrespective of bone. Foot ash is as suitable as tibia ash, but easier to determine. Bone ash data, especially the amount of foot ash, seem to be suitable indirect selection criteria for P efficiency breeding.

Genetics and Genomics of Social Behavior in a Chicken Model.

The identification of genes affecting sociality can give insights into the maintenance and development of sociality and personality. In this study, we used the combination of an advanced intercross between wild and domestic chickens with a combined QTL and eQTL genetical genomics approach to identify genes for social reinstatement, a social and anxiety-related behavior. A total of 24 social reinstatement QTL were identified and overlaid with over 600 eQTL obtained from the same birds using hypothalamic tissue. Correlations between overlapping QTL and eQTL indicated five strong candidate genes, with the gene TTRAP being strongly significantly correlated with multiple aspects of social reinstatement behavior, as well as possessing a highly significant eQTL.

Effects of Isolation on Stress Responses to Novel Stimuli in Subadult Chickens (Gallus gallus)

AbstractExtensive research has examined the effects of social isolation in neonatal and adult animal populations, but few studies have examined the effect of social isolation in early adulthood. Animals reaching reproductive age often experience extensive social changes as they leave their natal site, and a social stressor like isolation may uniquely affect this age group. Furthermore, adolescence is a time when sex differences in behavior become more pronounced. As such, the effects of social stressors are likely to vary by sex. In this study, we used noninvasive methods to evaluate stress responses to social change in male and female subadult chickens (Gallus gallus). Half of the birds experienced regular sessions of social isolation over the course of 2 wk, while the other half were never isolated. Subsequently, all of the animals were exposed to a suite of three novel probes, including an open‐field test. We monitored the birds’ behavioral (head movements) and physiological (fecal glucocorticoid metabolites, FGM) response to the tests. Our results indicate that, for subadult chickens, the effect of social isolation is sex dependent: Male FGM and behavioral responses did not change with subsequent experiences, in contrast to females. Females also exhibited more social reinstatement behavior compared to males. Our results are consistent with the expectations of differences between the sexes based on changes in the social environment due to sex‐biased dispersal patterns. For both sexes, the FGM and behavioral responses varied independently, which highlights the necessity for multiple measures of stress in animal populations.

A medium density genetic map and QTL for behavioral and production traits in Japanese quail.

BackgroundBehavioral 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 QTLs related either to behavioral (23) or production (22) traits. The most numerous QTLs (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).ConclusionThis 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-014-1210-9) contains supplementary material, which is available to authorized users.

Maternally derived egg hormones, antibodies and antimicrobial proteins: common and different pathways of maternal effects in Japanese quail.

Avian eggs contain a variety of maternally-derived substances that can influence the development and performance of offspring. The levels of these egg compounds vary in relation to environmental and genetic factors, but little is known about whether there are correlative links between maternal substances in the egg underlying common and different pathways of maternal effects. In the present study, we investigated genetically determined variability and mutually adjusted deposition of sex hormones (testosterone-T, androstenedione-A4 and progesterone-P4), antibodies (IgY) and antimicrobial proteins (lysozyme) in eggs of Japanese quail (Coturnix japonica). We used different genetic lines that were independently selected for yolk T concentrations, duration of tonic immobility and social reinstatement behaviour, since both selections for behavioural traits (fearfulness and social motivation, respectively) produced considerable correlative responses in yolk androgen levels. A higher selection potential was found for increased rather than decreased yolk T concentrations, suggesting that there is a physiological minimum in egg T levels. Line differences in yolk IgY concentrations were manifested within each selection experiment, but no consistent inter-line pattern between yolk IgY and T was revealed. On the other hand, a consistent inverse inter-line pattern was recorded between yolk IgY and P4 in both selections for behavioural traits. In addition, selections for contrasting fearfulness and social motivation were associated with changes in albumen lysozyme concentrations and an inverse inter-line pattern between the deposition of yolk IgY and albumen lysozyme was found in lines selected for the level of social motivation. Thus, our results demonstrate genetically-driven changes in deposition of yolk T, P4, antibodies and albumen lysozyme in the egg. This genetic variability can partially explain mutually adjusted maternal deposition of sex hormones and immune-competent molecules but the inconsistent pattern of inter-line differences across all selections indicates that there are other underlying mechanisms, which require further studies.

Evidence of Phenotypic and Genetic Relationships between Sociality, Emotional Reactivity and Production Traits in Japanese Quail

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.

Increasing group size decreases social bonding in young Japanese quail, Coturnix japonica

Social bonds between groupmates and social motivation can influence the stability of the social structure among domestic birds. Group size may also influence social stability, but no information is available about its influence on social bonding. We investigated the effect of group size and social motivation on the strength of social bonds between familiar Japanese quail chicks. The behaviour of quail selected for high (HSR) or low (LSR) social reinstatement behaviour and housed in different group sizes (6, 15 and 30 individuals) was recorded during two successive 10 min situations: separation and return of a cagemate or an unfamiliar conspecific. In both lines and for all group sizes, chicks formed social bonds with cagemates, shown by disturbance at separation and a greater calming effect of the return of a familiar versus an unfamiliar quail. LSR chicks might form stronger social bonds than HSR ones but our results do not allow us to conclude confidently on that point. With increasing group size, the calming effect and especially the positive social interactions decreased in both lines, indicating a weakening of the social bond between familiar conspecifics, perhaps because of the larger number of potential partners or the establishment of a tolerant social strategy based on less aggression, less time spent in contact and weaker bonds. Further investigations of the relationship between group size and social bonding in this species may allow us to determine why their social behaviour changes with increasing group size and to make more suitable social environments for domestic birds.

Effects of a 16-hour light, 8-hour dark lighting schedule on behavioral traits and performance in male broiler chickens

SUMMARY The objective of this study was to examine the effects of a 16L:8D lighting schedule from d 2 of age through a 6-wk production trial on the performance and behavior of Cobb broiler males compared with a continuous 24-h light schedule (control). Behavioral tests included social reinstatement behavior measured in runway tests and fear response measured by tonic immobility. The 16L:8D group had BW and FCR similar to control birds at 6 wk. Based on behavior observations by scan sampling at 0900 to 1100 h and 1400 to 1600 h, the number of chicks eating, drinking, walking-standing, and pecking increased under the 16L:8D lighting schedule, whereas resting (sitting and sleeping) decreased (P ≤ 0.05). The 16L:8D group also exhibited comfort behaviors, such as preening and wing-shaking, more extensively than did control birds (P ≤ 0.05). Broilers in the 16L:8D group had a shorter duration of tonic immobility (P ≤ 0.05) at 11 and 35 d of age, which might represent less fearfulness. In runway tests at 13 and 30 d of age, the 16L:8D group exhibited shorter latencies to reach the zone of stimulus birds and spent more time near the stimulus birds (P ≤ 0.05). We therefore suggest that the birds in the 16L:8D group had a greater degree of sociality. Although we did not measure whole-day activity, we speculate that this greater sociality might have resulted from increased interactions among birds caused by increased activity during the observation periods. The16L:8D program tended to have more natural daytime behavioral patterns in broilers, to reduce fearfulness (and thus psychological stress), and to increase sociality. We conclude, based on the morning and afternoon measurements of this study, that birds in the 16L:8D group had a better welfare status than control birds without affecting 42-d broiler performance of the strain used.

Do different yolk androgens exert similar effects on the morphology or behaviour of Japanese quail hatchlingsCoturnix japonica?

Avian eggs contain variable levels of several maternal androgens that may all be important in adjusting offspring phenotype at the individual or brood level. Most studies have focused on experimental manipulations of testosterone (T), and the other yolk androgens such as androstenedione (A4) and 5‐alpha‐dihydrotestosterone (DHT) were so far neglected. However, in species where the amount of A4in the yolk much exceeds that of the other androgens, A4could represent the dominant agent of androgen‐mediated maternal effects, in which case manipulations of T would be misdirected. We conducted our study in a species with high yolk A4and relatively low T and DHT levels, the Japanese quailCoturnix japonica. We injected unincubated eggs with a physiological dose of either A4, T, or DHT, and measured hatchling growth, as well as behaviour in an open field test. T treatment non‐significantly increased social reinstatement behaviour in the open field test, but it seemed to significantly suppress early skeletal growth and mass gain. The A4and DHT treatments, in contrast, significantly increased reinstatement behaviour, but did not affect mass and size growth. These results suggest that future investigations should view yolk androgens as integrated components of the complex yolk steroid environment.

Social motivation does not go hand in hand with social bonding between two familiar Japanese quail chicks, Coturnix japonica

Social bonds between conspecifics (sexual pairmates, parent–infant or siblings) and social motivation can influence the way birds interact. Social bonds between familiar conspecifics may also be formed, especially in chicks from precocial species in which behaviour is characterized by a strong social attraction. We investigated the establishment of such a bond and the effect of social motivation using a separation/reunion test in 1-week-old Japanese quail. In experiment 1, the behaviour of paired quail selected for high (HSR) or low (LSR) social reinstatement behaviour was recorded during three successive 10 min situations: baseline, separation and return of the cagemate. Both lines showed behavioural changes during social separation but the distress response was higher in the HSR line. Return of the familiar cagemate induced a return to baseline activity in both lines. The specificity of this response was tested in experiment 2 in which paired quail of both lines were separated, and their behavioural and vocal responses to the introduction of the familiar or an unfamiliar bird were compared. LSR chicks responded differently both behaviourally and vocally according to the familiarity of the introduced bird, whereas the response of HSR chicks differed only for aggressive pecks. HSR quail chicks thus revealed a nonspecific social attraction for conspecifics, whereas LSR chicks showed a bond with the cagemate. Our results highlight the importance of vocal communication as an indicator of the strength of the bond. Our findings show that high social motivation in quail chicks is not related to the development of a social bond.

Effect of the density of conspecifics on runway social reinstatement behavior of male Japanese quail genetically selected for contrasting adrenocortical responsiveness to stress

Runway tests are considered indicative of underlying sociality in birds and their ability to make social discriminations and establish interactions among conspecifics. Herein, social reinstatement behavior in male juvenile Japanese quail selected for a reduced (LS, low stress) or exaggerated (HS, high stress) adrenocortical response to brief mechanical restraint was evaluated. Individual males were given the choice to reinstate with either 2 (low density, LD) or 8 (high density, HD) unfamiliar randombred conspecifics placed in goal boxes at opposite ends of a two-choice runway (TCRW). Then, the same males were individually retested in a single goal box runway wherein they were exposed to a goal box containing either a LD or a HD of males. In the TCRW, a higher (P < 0.01) number of HS males started their ambulation toward the goal box containing the HD as opposed to LD of conspecifics. The HS males also spent more (P < 0.01) time in close proximity (within a 10-cm close zone; CZ) to the HD (218 s) rather than LD (57 s) of conspecifics. In contrast, the LS males did not differ in their initial direction of travel and they spent similar average amounts of times in the CZ of their stimulus LD (141 s) and HD (124 s) conspecifics. Similar to the TCRW results, in the single goal box runway, HS males spent more (P < 0.01) time in the CZ of HD rather than LD conspecifics, whereas LS quail spent similar amounts of time in the CZ of LD and HD males. Considering that runways are novel (and therefore frightening) environments, our findings suggest that HS quail may find better shelter (i.e., more comfort) in close proximity to a larger rather than smaller group of conspecifics, whereas LS birds find groups of varying conspecific density equally attractive. The results suggest that LS quail possess favorable social adaptive qualities because they appear to be better suited to cope with situations where the density of conspecifics is variable.

Social motivation affects the display of individual discrimination in young and adult japanese quail(Coturnix japonica)

A simultaneous two-choice test was used to investigate discrimination between a familiar (F) and an unfamiliar conspecific (U) in Japanese quail, selected for high (HSR) or low (LSR) social reinstatement behavior (tendency to rejoin and stay close to conspecifics). Animals were 1-week unsexed and 6-week-old male quail. One-week-old LSR quail and 6-week-old male HSR quail displayed discrimination after 24 hr of pair contact (p < 0.05), and a tendency to discriminate (p < 0.10) was found in adult male LSR quail. After 1 week of pair contact, results were similar in LSR quail chicks, but no discrimination was evidenced in adult quail of either line. Therefore, Japanese quail are able to discriminate between a familiar cagemate and an unfamiliar conspecific after only 24 hr of pair contact. Moreover, this study reveals for the first time in this species that social motivation and age both influence the display of individual discrimination.

Intensity and duration of corticosterone response to stressful situations in Japanese quail divergently selected for tonic immobility

Two genotypes of Japanese quail have been divergently selected since the 1980s for long (LTI) or short (STI) duration of tonic immobility [Mills, A.D., Faure, J.M., 1991. Divergent selection for duration of tonic immobility and social reinstatement behavior in Japanese quail ( Coturnix coturnix japonica) chicks. J. Comp. Psychol. 105(1), 25–38.], an unlearnt catatonic state characteristic of a behavioral fear response ([Jones, R.B., 1986. The tonic immobility reaction of the domestic fowl: a review. World’s Poult. Sci. J. 42(1), 82–97.]; [Mills, A.D., Faure, J.M., 1991. Divergent selection for duration of tonic immobility and social reinstatement behavior in Japanese quail ( Coturnix coturnix japonica) chicks. J. Comp. Psychol. 105(1), 25–38.]). The results of several behavioral tests conducted in LTI and STI quail have led to the conclusion that LTI quail are more fearful than STI quail [Faure, J.M., Mills, A.D., 1998. Improving the adaptability of animals by selection. In: Grandin, T. (Eds.), Genetics and the behavior of domestic animals. Academic Press, San Diego, pp. 235–264.]). However, few studies to date have focused on the Hypothalamic-Pituitary-Adrenal (HPA) axis response to stressful situations in LTI and STI quail, although the HPA axis is involved in fear responses [Siegel, H.S., 1971. Adrenals, Stress and the Environment. World’s Poult. Sci. J. 27, 327–349.]. The corticosterone (CORT) response to various putatively stressful situations was therefore assessed in LTI and STI genotypes of quail in order to investigate their HPA axis reactivity to stress. Repeated induction of TI or 1 min manual restraint induced significant and comparable increases in CORT levels in both genotypes as a TI response. On the other hand, higher CORT responses were found in STI than in LTI quail when the manual restraint period lasted for 2 min or after restraint in a crush cage. Maximum CORT responses and genotype differences were maintained throughout the latter test even when it lasted for 120 min. Investigation of the CORT response to a single TI episode showed that CORT levels at the end of TI were negatively correlated with TI duration. Other experimental contexts consisting of isolation in a familiar or novel environment or the presentation of a novel object induced slight but significant and comparable increases in CORT response in both genotypes, whereas change of cagemates did not. In conclusion, the present findings indicate that differences in HPA axis response are observed between LTI and STI genotypes when quail are submitted to intense stressors, resulting in a high and prolonged CORT response. By contrast, plasma corticosterone concentrations do not differ between STI and LTI quail in response to stressful situations of lower intensity, which evoke responses limited in amplitude and duration. Genetic selection for divergent duration of TI has thus affected the HPA axis response to stress, and LTI and STI quail constitute an interesting model to investigate genetic variability of HPA axis activity in birds. More specifically, these genotypes of quail could be used to investigate the occurrence of functional differences at different levels of the HPA axis in order to explain the present findings.

Social versus exploration and foraging motivation in young red junglefowl ( Gallus gallus) and White Leghorn layers

Social coherence tendency is an important behavioural characteristic in young fowl related to an underlying social motivation that can be modified by breeding. Our aim was to investigate if selection for productive traits in a certain White Leghorn layer strain has influenced different components of social motivation compared to the ancestor, red junglefowl. From both breeds, 29 chicks were tested between 4 and 7 weeks of age in four behavioural tests designed to study social motivation. A runway test was used to measure social reinstatement behaviour. Social coherence tendency versus foraging motivation was measured in both novel and familiar environments following 0 and 3 h food deprivation. The novel environment was an L-shaped social versus foraging arena and the familiar environment was identical to the chicks’ home pens. Both included stimulus birds in a box and food at opposite ends of the test arenas. Furthermore, spacing behaviour of groups consisting of three chicks was observed in a novel pen. The runway test revealed a stronger social affiliation in junglefowl when the social contact had first been reinstated. In the social versus foraging arena, junglefowl moved more whereas Leghorns spent more time immobile. These differences were greater with 3 h food deprivation. Deprivation and breed had a significant interaction resulting in more time spent feeding by junglefowl but not by Leghorns. Contrary to this, in the familiar pen, Leghorns responded to deprivation by feeding more and keeping longer distance to the stimulus birds than junglefowl. In the novel pen, Leghorn chicks had shorter nearest neighbour distances than junglefowl. The results indicate that the adaptability of the birds to their social and physical environment may have been influenced by means of selection for increased production capacity. Leghorns from the studied strain may have greater problems in adapting to a new environment.

Ease of capture in lines of Japanese quail ( Coturnix japonica) subjected to contrasting selection for fear or sociability

Japanese quail ( Coturnix japonica) of lines, which have been subjected to contrasting selection for duration of the tonic immobility (TI) reaction or social reinstatement (SR) behaviour over many generations show corresponding differences in underlying fearfulness and sociality. As fearfulness and sociality are particularly influential traits in domesticated species, the finding that such traits respond to artificial selection may have important implications for poultry welfare and performance. However, it is not known if or how such selection has influenced human–animal interactions. The present experiment investigated the influence of fearfulness and SR behaviour on the ease with which birds could be caught and handled. Birds of lines selected for duration of the TI response or SR behaviour were reared in mixed line groups (LTI and STI or HSR and LSR) of 491 and 346 birds, respectively, until 6 weeks of age. When the birds were 2, 4, and 6 weeks of age, they were caught one by one and their individual capture ranks noted. In the group of birds selected for duration of the TI response, birds selected of the line selected for short duration of TI were caught before those selected for long duration of the response. In the group of birds selected for SR motivation, birds of the high line were caught before their low lines counterparts. Coefficients of concordance between capture ranks were significant and capture ranks did not differ significantly across ages. These results imply that selection for low levels of fear or high levels of sociality produces animals that are less disturbed by human interventions than animals selected for the opposite traits. The greater ease of capture of low fear line birds than high fear line birds may be explained by reduced fear of humans. The fact that the birds selected for high levels of SR behaviour are easier to catch than birds selected for low levels of sociality is less readily explicable. One hypothesis is that HSR line chicks tend to be more strongly imprinted on each other and the human caretaker. However, SR behaviour is highly species specific in both lines, existing evidence for line differences in social discrimination is limited and birds of the two lines show similar duration of the TI response. Despite this, whatever their underlying causation, these results demonstrate that genetic selection can be used to reduce negative reactions to human beings and may be of value in the improvement of both animal welfare and productivity.

Effect of group disruption on social behaviour in lines of Japanese quail ( Coturnixjaponica) selected for high or low levels of social reinstatement behaviour

Japanese quail of lines selected for high (HSR) or low (LSR) levels of social reinstatement (SR) behaviour were reared in groups of three. At 3 and 6 weeks of age, one group member was replaced with an unfamiliar conspecific bird. Behaviour following introduction of the intruder was similar at both ages. Quail of both lines spent more time immobile after introduction of the intruder than before its introduction. In the LSR, but not the HSR line, inter-individual distances between intruders and other chicks, were greater than those between familiar chicks. Birds of both lines pecked more between unfamiliar than between familiar birds. Pecks, not associated with escape or avoidance by the pecked bird, were more frequent in HSR groups. Selection for HSR behaviour appears to have increased non-aggressive exploration of intruder whereas selection for LSR behaviour has decreased interest in or increased shunning of intruders.

Inter-individual distances during open-field tests in Japanese quail ( Coturnix japonica) selected for high or low levels of social reinstatement behaviour

Inter-individual distances (IIDs), during open-field tests, were measured in single sex pairs of quail of lines divergently selected for high (HSR) or low (LSR) levels of social reinstatement (SR) behaviour. Tests were carried out when the chicks were 1-, 3- and 6-weeks of age. IIDs were established within 1 min and remained stable thereafter. In HSR and mixed line pairs, but not LSR line pairs, IIDs increased with age. IIDs were shorter in HSR line pairs than in LSR or mixed line pairs at 1- and 3-weeks of age but not at 6-weeks of age when IIDs were similar in all pair-types. At 1- and 3-weeks of age, IIDs in mixed line pairs were intermediate to those in HSR and LSR line pairs. The sex of the pair-members did not influence IIDs. Previous studies have shown that selection for SR behaviour, in quail chicks, has effects that persist into later life and influence characters not present in the birds’ behavioural repertoire at the time of testing for the purposes of selection. Such behaviour patterns include aggression, sexual behaviour and socio-sexual proximity behaviour. All of these behaviour patterns are expressed at higher levels in HSR line birds than LSR line birds. Differences in IIDs between HSR and LSR line birds may, therefore, be due to an interaction between environmental and genetic effects. In young HSR chicks, social reinstatement is the primary motivation and IIDs are short. However, as the HSR line chicks’ age, IIDs reflect an interaction between social attraction and aggression related avoidance behaviour that tends to increase IIDs. In LSR line chicks aggression and social motivation are low at all ages and IIDs tend to remain stable.

Effects of genetic selection for fearfulness or social reinstatement behavior on adult social and sexual behavior in domestic quail (Coturnix japonica)

Male quail (Coturnix japonica) were genetically selected for high or low levels of social reinstatement behavior (weighted for independence from inherent fearfulness) and high or low fearfulness (weighted for independence from social reinstatement behavior). Genetic selection was based on tests conducted during the first 10 days after hatching. Inherent fearfulness was inferred from a test of the tonic immobility response, and social reinstatement behavior was measured in a treadmill test. When tested in adulthood, males selected for high levels of social reinstatement behavior showed more social proximity behavior, shorter latencies to copulate with a female, larger numbers of copulatory responses, and greater copulatory efficiency than did males selected for low inherent fearfulness. The other genetic lines performed at intermediate levels. Thus, the effects of genetic selection extended into adulthood and influenced responses that were not in the behavioral repertoire of the birds at the time of selection. Interestingly, selection for inherent fearfulness did not necessarily disrupt sexual performance. In fact, fearfulness appeared, at least to some extent, to be conducive to the expression of male sexual behavior.

Anxiogenic-like effects of Tagetes minuta L essential oil on T-maze and tonic immobility behaviour in domestic chicks.

In a first experiment, four doses (ranging between 0.04 and 0.45 mg/kg of body weight) of the essential oil from Tagetes minuta L. were subcutaneously injected in two-day-old chicks and a dose-response curve assessed for escape performance in a T-maze test. The 0.1, 0.25 and 0.45 mg/kg doses impaired the first escape performance suggesting an anxiogenic-like effect of the essential oil. After 3 h the same chicks were tested for a second escape performance, without being injected again, and no differences were observed compared to controls, suggesting that the essential oil did not affect retention. Furthermore, the effects of the essential oil were observed in the three sections of the T-maze apparatus. So, the performance was impaired in the isolation chamber section, suggesting the induction of increased anxiogenic behaviour, and also in the mirror section, suggesting that the social reinstatement behaviour was modified by an increased anxiety level. Changes in the principal corridor section were not observed, suggesting that the locomotor activity was not affected by these oil doses. The second escape performance was not affected in any of the T-maze sections, confirming that these doses did not affect learning ability. In a second experiment, a middle dose of the essential oil (0.25 mg/kg) increased the tonic immobility reaction in 15 days old chicks similarly to an anxiogenic dose of FG 7142 (1 mg/kg), while an anxiolytic dose of diazepam (0.08 mg/kg) did not affect this behaviour. Taken together, the present results suggest that the essential oil from Tagetes minuta L. may exert a negative modulation on the GABAergic function without affecting the learning ability.