<p>Early life stress is something that animals used in production often have to experience. What we do not know is if there are any consequences of this treatment later on in life. Zebra finches postnatal treated with the stress hormone corticosterone showed an exaggerated and prolonged stress response later on. To examine the effects of early life stress 77 White Leghorn chicks were used, half of them was stressed from postnatal day 1-14 and then tested between 47-63 days of age. The tonic immobility (TI) test is a commonly used test to evaluate the fearfulness and stress reaction in fowl. The chicks were placed on their back in a V-shaped wooden cradle and TI was induced by applying light pressure on the breast and neck. The number of inductions required to induce TI was recorded as well as the time until the first alert head movement and the total duration of the TI. The birds were tested in a calm environment but also after a stressful situation. There were no differences in the total duration of the TI reactions. However, stressed animals tended to need more induction attempts than the control animals. While looking at the time elapsed until the first head movement stressed chicks had a significantly lower duration. This indicates a dullness or shift in the stress response of the treated birds and there seem to be a more exaggerated response in the males.</p>

Early life stress is something that animals used in production often have to experience. What we do not know is if there are any consequences of this treatment later on in life. Zebra finches postnatal treated with the stress hormone corticosterone showed an exaggerated and prolonged stress response later on. To examine the effects of early life stress 77 White Leghorn chicks were used, half of them was stressed from postnatal day 1-14 and then tested between 47-63 days of age. The tonic immobility (TI) test is a commonly used test to evaluate the fearfulness and stress reaction in fowl. The chicks were placed on their back in a V-shaped wooden cradle and TI was induced by applying light pressure on the breast and neck. The number of inductions required to induce TI was recorded as well as the time until the first alert head movement and the total duration of the TI. The birds were tested in a calm environment but also after a stressful situation. There were no differences in the total duration of the TI reactions. However, stressed animals tended to need more induction attempts than the control animals. While looking at the time elapsed until the first head movement stressed chicks had a significantly lower duration. This indicates a dullness or shift in the stress response of the treated birds and there seem to be a more exaggerated response in the males.

Social support is thought to give animals benefits from social partners, such as improved coping with challenges. The aim of this study was to investigate differences in social support in the red junglefowl (RJF) and a domestic layer strain, the White Leghorn (WL). A runway test consisting of two compartments with unfamiliar and familiar stimulus animals was used to measure social motivation before and after a stressful experience. Total number of test animals was 56 divided into four groups; male and female WL as well as male and female RJF. Results showed that females preferred to stay close to familiar conspecifics after stress treatment. Before stress treatment there was little difference between either sex of WL while RJF males and females chose different zones. Females preferred familiar conspecifics, indicating that they rely more on familiar social stimuli for social support. Males of the two breeds behaved differently towards stimulus animals. WL males showed aggression towards familiar stimulus animals while RJF males directed aggression towards unfamiliar stimulus animals. Indication of sexual behavioural dimorphism was supported while further research is needed in domestication effects on social support in chickens.

When animals are stressed they use a trait called social support to alleviate their stress responses. With domestication many traits from the ancestor red junglefowl have changed in the domesticated breed white leghorn. White leghorns are bred to be able to live in large groups where it becomes hard to recognize every chicken. They are therefore not as dependent of familiar stimuli birds for social support as red junglefowl. Our hypotheses were that red jungle males would be more interested in unfamiliar stimuli birds than white leghorn male before stress due to their territoriality. We tested total 56 chickens in an open field test. The test arena was divided in three zones and the time the focal birds spent in each zone was recorded. The focal bird was recorded in 300 seconds before being stressed by being suspended in a net and then recorded again in 300 seconds. The results showed that social support and social behaviour differs between females and males for both breeds. No significant differences were found between the breeds. There was a tendency for significant of breed (P=0.08) effects in the central zone unstressed. The two interactions before stressed between breed and sex, central zone (P&lt;0.01) and unfamiliar zone (P&lt;0.01) had significant effects. We observed fights between white leghorn males and familiar stimuli. Waltzing did also occur in red jungle males in front of unfamiliar. In conclusion, numeric differences can be seen but not large enough to be significant and our hypotheses are not confirmed.

Domestication has taken place over thousands of years and during that time we have bred animals on different traits. The red jungle fowl is the ancestor to all domesticated chicks, including the white leghorn which is used in egg production. The domestication of the red jungle fowl has resulted in behavioral changes between itself and domesticated breeds, such as white leghorn. In this study we examine how these two breeds handle stress and whether or not they use social support when coping and recovering from a stress experience. The study took place in a built arena with two stimuli animals on each side. There the animal was studied for 5 minutes, stressed for 3 minutes and studied again for 5 minutes. We found that the red jungle fowl males spent more time in the unfamiliar zone before stress than males of the white leghorn. Our results also showed that the females of white leghorn and red jungle fowl spent more time in the familiar zone than males after being stressed. This is an indication that they are more dependent on social support from familiar animals after stress than the males are. Aggressive behavior was also observed among the males. Red jungle fowl males acted aggressively towards the unfamiliar stimuli animals and the white leghorn towards the familiar stimuli animals. In conclusion, we found that the females where in greater need of social support than the males. / Biologi

Domestication of animals has given rise to a great phenotypic divergence in selected animals and rapidly generated species of animals more accustomed to human contact and social interactions within the species. Previous studies in chickens (Gallus gallus) have managed to find behavioral and adaptive differences between Red Junglefowl (RJF) and White Leghorn (WL), differences inherent to the domestication process. These phenotypic changes could spawn from a variety of different genomic factors, including an epigenetic gene expression regulatory mechanism known as CpG methylation, a DNA modification of CpG dinucleotides that in turn affect nucleosome formation. In this study we investigated the methylation differences between RJF and WL. This by selecting genes that has previously been shown to be both differentially expressed (DE) and differentially methylated (DM) between RJF and WL, and had shown the same kind of differences in both parental animals and their offspring. By using methylation-sensitive high-resolution melting (MSHRM) we tried to confirm previous DM result, and four genes; FUCA1, RUFY3, PCDHAC1 and TXNDC16 were tested and verified to be DM between RJF and WL.

Den biologiska studien har visat att värphöns genom domesticeringen förändrat och anpassat sina beteenden till att leva med människor. De har utvecklat en minskad rädsla för människor och en ökad stresstålighet. I denna studie har höns återhämtning efter en stressupplevelse studerats. För att se hur domesticeringen har påverkat återhämtningen jämfördes beteenden mellan raserna White Leghorn och red junglefowl. Frågeställningarna som användes för att undersöka detta var: Hur lång tid tar det innan höns återhämtar sina naturliga beteenden, ej stressrelaterade, efter en stressupplevelse? Finns det några skillnader i återhämtningen beroende av kön eller mellan raserna White Leghorn och red junglefowl? Resultatet visade inte på en specifik tid för återhämtning men på att en tydlig återhämtning förekom. Återhämtningen visades i beteendena Relaxed Behaviour, Comfort Behaviour, Perch, Vocalisation och Stand Alert genom att uppvisandet av beteendena skiljde sig signifikant med tiden. Även signifikanta skillnader visades mellan raserna, både i beteenden som visade på återhämtning och i beteenden som inte gjorde det. En slutsats om vilken ras som återhämtade sig snabbast var svår att dra. Detta på grund av att beteendeskillnaderna visade på olika tendenser gällande återhämtning. Skillnaderna i återhämtningen mellan könen, visades tendenser på att hanarna återhämtade sig snabbare. Domesticering har även i denna studie studerats utifrån ett lärarperspektiv. Undersökningen visade att domesticering kan ingå i biologiundervisningen i områdena evolution och genetik i år 7-9. / The biological study has shown that behaviour of laying hens has changed through domestication and the hens have adapted to live with humans. They have developed less fear of humans and more resistance to stress. In this study hens’ recovery after a stressful experience has been studied. A comparison between the breeds White Leghorn and red junglefowl has been made to see how the domestication has affected the recovery. The questions of this study are therefore: How long does it take for hens’ to recover their natural behaviour, not stressrelated, after a stressful experience? Are there any differences in recovery between the different breeds White Leghorn and red junglefowl? The results did not show a specific time for recovery, but a distinct recovery was noticed in Relaxed Behaviour, Comfort Behaviour, Perch, Vocalisation and Stand Alert. This beacause of the behaviours differed significantly with time. Also significant differences existed between the breeds, both in behaviours that showed recovery and in behavious that did not. A conclusion of what breed that recovered fastest was difficult to make. This because of the differences of behaviour showed different tendencies in recovery. The differences in recovery between the sexes showed tendencies that the males recovered fastest. The domestication has also been studied from a teacherperspective. The study showed that domestication can be a part of biologyeducation in the fields of evolution and genetics in the grades 7-9.

Många elever ser naturvetenskapliga ämnen som svåra och tappar lätt intresset om inte läraren presenterar ämnet tillfredsställande. Jean Piaget har haft stor betydelse inom pedagogiken, då han menade att intelligens är en metod som barn kan lära sig genom att utforska och laborera. Genom möjligheten att få göra en observationsstudie på höns kom tanken att omarbeta denna till ett etologiprojekt för biologiämnet på gymnasiet. Projektet innebär att eleverna får arbeta med en observationsstudie från grunden, och goda möjligheter finns att integrera andra ämnen i detta. Människan började domesticera höns för tusentals år sedan, en process där djur utvecklar ett adaptivt beteende till människan och dess miljö. Drygt hundra år tillbaka startade den intensiva aveln på höns som gett upphov till dagens tamhöns (Gallus gallus domesticus). White Leghorn är en av de domesticerade raserna avlad för hög äggproduktion, och härstammar från det röda djungelhönset (Gallus gallus). Studiens syfte var att se hur lång tid det tog för höns att återhämta sig efter en stressupplevelse och om det fanns en skillnad i återhämtningsförmågan mellan raserna. Resultaten tyder på att hönsen återhämtat sig efter 130 minuter, men vissa beteenden visade en signifikant skillnad med avseende på ras, kön och tid. White Leghorn verkade bli mer påverkade av stressmomentet och uppvisade både stressade och avslappnade beteenden. Trots detta verkar de ha en effektivare återhämtning än djungelhönsen som uppvisade procentuellt mer komfortbeteenden, vilket i detta sammanhang kan indikera stress då olika beteendemekanismer kan interagera i djuret och trigga igång ett utforskande beteende vid låga stressnivåer.

Tidigare studier har visat att domesticerade höns påvisar en lägre nivå av rädsla jämfört med förfadern, de röda djungelhönsen. I denna studie testades 18 domesticerade White Leghorn (WL) och 18 röda djungelhöns (RJF). Målet med studien var att studera återhämtningen för de båda raserna vid en standardiserad stressupplevelse. Försöket gick ut på att hönsen vistades i enskilda burar och blev efter ett dygn utsatta av en akut stress. Därefter startades observationerna omedelbart för att se när hönsen återhämtade sig och återigen började visa naturliga beteenden. Utifrån alla hönsens resultat beräknades medelvärde och standardfel för varje ras och kön, som sedan jämfördes med variansanalys (repeated measures ANOVA). Beteenden som visade signifikanta resultat över tiden analyseras och visade i några fall tyda på en återhämtningsprocess. Överlag visade White Leghorn på en snabbare och effektivare återhämtning jämfört med de röda djungelhönsen. Resultatet tyder även på att honor har en snabbare återhämtning jämfört med hanar. Studien innehåller även ett didaktiskt moment då etologi studerades utifrån skolverkets föreskrifter om vad biologiundervisning ska innehålla för grundskolans senare år. Läroplanen och kursplaner studerades därefter och jämfördes med läroböcker.

Stress affects a number of animals and is a survival mechanism. During stress, changes in the animal’s physiological mechanisms and changes in behavioural reactions will happen. This study evaluates four different stressors that can occur in a chicken’s life. The four stressors are fixation, social isolation, predation and transport. 40 White Leghorn chicken from age sex to seven weeks were used in the study. An open-field test was used to evaluate the stressors. The open-field test registered time for ambulation, time for first change of zones, number of zones used and number of registrations in central zones. The chicken was expected to ambulate in the open-field arena since chickens are curious but the activity was expected to be different depending on which stressor the chicken was exposed to. Previous studies have shown that more stressed birds are less active in an open-field test than birds that are not stressed. A control group was included in the study and this group was not exposed to a stressor. The results did not show any significant dereferences between time for the first change of zones, number of zones used and number of registrations in central zones. However, there was a tendency for a significant difference in time to first ambulation. The results suggested that the control group and the group that was exposed to social isolation displayed most stress-related behaviour. Least stressed was the predation group and the transport group.