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Fritz Trillmich - One of the best experts on this subject based on the ideXlab platform.
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within family environment and cross fostering stress affect behavior and physiology in wild cavies Cavia aperea
Frontiers in Psychology, 2020Co-Authors: Sabine Kraus, Anja Guenther, Fritz TrillmichAbstract:Stability of personality traits is well documented for a wide variety of animals. However, previous results also suggest that behavioural phenotypes are plastic during early ontogeny and can be adaptively shaped to the social environment. In cavies (Cavia aperea), it has already been documented that the size at birth relative to siblings (size rank) greatly influences various behavioural and physiological traits that last at least until independence. The aim of the current study was (1) to investigate if behavioural and physiological differences between pups of the same litter persist until after independence and influence development long-lasting, (2) to determine the potential plasticity in response to changes in the early within-family environment by cross-fostering pups either to the same, a lower, or a higher size rank in a foster-family. We measured three behavioural traits (number of interactions with a novel object, distance moved in an open field, struggle docility) and two physiological traits (resting metabolic rate and basal cortisol levels). We predicted that cross-fostering into a litter where pups occupy the same size rank would not change the expression of traits. Cross-fostering to a different size rank should not influence the expression of traits if repeatability measures indicate low plasticity. Alternatively, if the traits are plastic, animals should adjust trait expression to fit with the size rank occupied in the foster litter. Initial differences in struggle docility, distance moved in an open field and in baseline cortisol concentration between pups of different size-ranks did not remain stable beyond independence. In addition, we found remarkable plasticity of the measured traits in response to cross-fostering to the same, a smaller or larger size-rank, suggesting that differences between pups are more the result of social constraints leading to adaptive shaping of individual phenotypes within a family. We also found a significant influence of the cross-fostering procedure itself. Cross-fostered individuals were less bold, grew slower and showed elevated resting metabolic rates. This finding suggests a cautious interpretation of previous cross-fostering studies and stresses the need for proper control groups to reliably separate the effect of cross-fostering per se from those induced by an experimental treatment.
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animal housing and welfare effects of housing conditions on body weight and cortisol in a medium sized rodent Cavia aperea
Journal of Applied Animal Welfare Science, 2014Co-Authors: Kathrin Schumann, Anja Guenther, Katarina Jewgenow, Fritz TrillmichAbstract:Rodents are the most abundant experimental nonhuman animals and are commonly studied under standard laboratory housing conditions. As housing conditions affect animals' physiology and behavior, this study investigated the effects of indoor and outdoor housing conditions on body weight and cortisol level of wild cavies, Cavia aperea. The changing housing condition strongly influenced both parameters, which are commonly used as indicators for animal welfare. The transfer from outdoor to indoor enclosures resulted in a body-weight loss of about 8%. In contrast, animals kept indoors showed a substantial weight gain of about 12% when they were transferred outdoors. These effects were reversible. To substantiate a connection between body-weight changes and the health states of the animals, blood basal cortisol concentrations were measured. Animals kept outdoors had significantly lower cortisol levels than did animals kept indoors. These results imply that indoor conditions have a direct effect on the animals' s...
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learning and personality types are related in cavies Cavia aperea
Journal of Comparative Psychology, 2014Co-Authors: Anja Guenther, Vera Brust, Mona Dersen, Fritz TrillmichAbstract:: The evolution and maintenance of consistent individual differences, so called animal personalities, have attracted much research interest over the past decades. Variation along common personality traits, such as boldness or exploration, is often associated with risk-reward trade-offs. Individuals that are bolder and hence take more risks may be more successful in acquiring resources over the short term. Cautious individuals taking fewer risks may, on the other hand, live longer, but may also gather fewer resources over the short term. According to recent theory, individual differences in personality may be functionally related to individual differences in cognitive performance (i.e., the way in which individuals acquire or use information). Individual differences in the acquisition speed of cognitively challenging tasks are often associated with a speed-accuracy trade-off. Accuracy can be improved by investing more time in the decision-making process or, conversely, decisions can be made more quickly at the cost of making more mistakes. Hence, the speed-accuracy trade-off often involves a risk-reward trade-off. We tested whether 3 personality traits, boldness, activity, and aggressiveness, are correlated with individual learning, associative learning speed, and behavioral flexibility as assessed by reversal learning in wild cavies (Cavia aperea). We found strong positive relationships between all personality traits and learning speed, whereas flexibility was negatively associated with aggressiveness. Our results support the hypothesis that performance reflects individual differences in personality in a predictable way. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
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photoperiodic effects on reproductive development in male cavies Cavia aperea
Physiology & Behavior, 2014Co-Authors: Anja Guenther, Mona Dersen, Rupert Palme, Sylvia Kaiser, Fritz TrillmichAbstract:Abstract Age at maturity is a particularly important life history parameter, as it predicts potential life time reproductive success in many small mammal species. Animals should therefore optimize the timing of maturation by reacting to environmental stimuli that predict future environmental conditions. Photoperiod often reliably predicts ecological conditions. Animals born into a photoperiod indicating favorable conditions (spring, summer) may mature earlier and at a lower weight than animals born into conditions indicating unfavorable conditions (autumn, winter). So far most work was done on small, altricial rodent species and we still lack knowledge about their precocial relatives. Precocial animals are born much further developed than altricials and might show less plasticity in their ontogenetic trajectory than the latter. We tested the influence of photoperiod simulated by increasing (spring) or decreasing (autumn) light in climate chambers on important life history parameters in a medium sized rodent, the highly precocial cavy ( Cavia aperea ). We wanted to determine whether photoperiod influences timing of maturation and early growth in male cavies and whether patterns of testosterone in blood are reflected by patterns of testosterone metabolites in feces. Males born into simulated spring grew faster and matured at an earlier age than males born into simulated autumn conditions. Patterns of testosterone in blood correlated with testosterone metabolites measured in feces. Male cavies strongly react to predictive photoperiod cues by adjusting growth and timing of maturation as we found previously for females, corroborating the importance of seasonal cues for adjustments of life history.
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Mother is not like mother: concurrent pregnancy reduces lactating guinea pigs' responsiveness to pup calls
Behavioural Processes, 2009Co-Authors: Marc Naguib, Melanie Kober, Fritz TrillmichAbstract:Offspring signalling can serve to communicate need to the parents and thus influence parental readiness to provide care. Offspring stimuli that affect parental care have been investigated extensively. Yet much less is known about the mechanisms leading to a decline in maternal motivation when conflicts of provisioning current and future offspring may arise. Here we tested responses by pregnant and non-pregnant female guinea pigs (Cavia aperea f. porcellus) to playback of pup calls during their period of lactation for dependent offspring. Most concurrently pregnant and lactating females did not respond to pup calls, whereas non-pregnant lactating females responded strongly. Our findings expand on previous studies by showing that female behavioural responsiveness to pup stimuli is strongly reduced by concurrent pregnancy and lactation. These instantaneous measurements of female responsiveness to young show more directly than standard measures like nursing performance or time to weaning how female motivation to care for current offspring is diminished by simultaneous gestation.
Norbert Sachser - One of the best experts on this subject based on the ideXlab platform.
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Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs
Frontiers in Zoology, 2010Co-Authors: Lars Lewejohann, Norbert Sachser, Thorsten Pickel, Sylvia KaiserAbstract:Background Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig ( Cavia aperea f. porcellus ), starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea . Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment. In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Results Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. Conclusion The results demonstrate that domestic guinea pigs do not at all perform worse than their wild relatives in tests of spatial learning abilities. Yet, the contrary seems to be true. Hence, artificial selection and breeding did not lead to a cognitive decline but rather to an adaptation to man-made environment that allows solving the task more efficiently.
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body weight and rearing conditions of males female choice and paternities in a small mammal Cavia aperea
Ethology, 2008Co-Authors: Oliver Adrian, Gabriele Dekomien, Jorg T Epplen, Norbert SachserAbstract:Patterns of mate choice may be important determinants of a species’ social organisation and mating system. At least two different aspects of female mate choice can be distinguished: choice of a social partner and choice of the genetic father of the offspring. Different characteristics of males can qualify them for these two roles. Although social and reproductive partners have been shown to differ in many species, social association times are often used in laboratory choice tests to infer reproductive preferences. The traits for which females may choose partners are diverse. Body size can correlate with the male’s strength in defending resources or other abilities benefiting the female and her offspring. In species living in social groups, social skills learned from group members during infancy can be important for later reproductive success. In this laboratory study, we conducted choice tests with wild cavies, Cavia aperea, a harem-living species of South American rodents, to determine social preferences of females towards two simultaneously available males. For offspring sired during these tests, paternities were determined by microsatellite DNA profiling. Males used in the tests differed in body weight and in rearing conditions: Half of the males had been reared in the presence or absence of their father, respectively. Male rearing conditions had no effect on either female social preferences or paternities. Females significantly preferred heavier males as social partners. In five of six tests, the heavier male also sired the offspring. Sires were in most cases but not consistently socially preferred. Heavier males may be preferable as social partners because they are better able to provide females with resources or have more experience in paternal care or predator avoidance as weight correlates with age. When choosing reproductive partners, females may prefer other male traits and the distribution of paternities may also be influenced by sperm competition.
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social organization predicts nature of infant adult interactions in two species of wild guinea pigs Cavia aperea and galea monasteriensis
Journal of Comparative Psychology, 2006Co-Authors: Michael B Hennessy, Sylvia Kaiser, Gesa Neisen, Katie L Bullinger, Norbert SachserAbstract:The authors compared interactions of infants with mothers and unfamiliar females in a novel environment in 2 caviomorph rodent species: the harem-living Cavia aperea, the probable progenitor of the domestic guinea pig; and the pair-living Galea monasteriensis. In C. aperea, interactions with mothers and unfamiliar females were largely similar; in G. monasteriensis, interactions with the mother, but not unfamiliar female, were characterized by physical closeness and sociopositive behavior. In G. monasteriensis, plasma cortisol levels were lower when with the mother than when with the unfamiliar female. Results are consistent with the species' social organizations and suggest that behavioral interactions of pups with mothers and other females in domestic guinea pigs reflect primarily the social organization of the progenitor species rather than domestication.
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Social Organization Predicts Nature of Infant–Adult Interactions in Two Species of Wild Guinea Pigs ( Cavia aperea and Galea monasteriensis )
Journal of Comparative Psychology, 2006Co-Authors: Michael B Hennessy, Sylvia Kaiser, Gesa Neisen, Katie L Bullinger, Norbert SachserAbstract:The authors compared interactions of infants with mothers and unfamiliar females in a novel environment in 2 caviomorph rodent species: the harem-living Cavia aperea, the probable progenitor of the domestic guinea pig; and the pair-living Galea monasteriensis. In C. aperea, interactions with mothers and unfamiliar females were largely similar; in G. monasteriensis, interactions with the mother, but not unfamiliar female, were characterized by physical closeness and sociopositive behavior. In G. monasteriensis, plasma cortisol levels were lower when with the mother than when with the unfamiliar female. Results are consistent with the species' social organizations and suggest that behavioral interactions of pups with mothers and other females in domestic guinea pigs reflect primarily the social organization of the progenitor species rather than domestication.
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Paternal behaviour in wild guinea pigs: a comparative study in three closely related species with different social and mating systems
Journal of Zoology, 2005Co-Authors: Oliver Adrian, Ina Brockmann, Christa Hohoff, Norbert SachserAbstract:In most species, females invest more in their offspring than males. In mammals, this also holds true after the birth of young since only mothers can lactate and fathers are thus more likely to desert and seek additional mating opportunities. These opportunities are largely dependent on resource distribution and the resulting distribution of females. The emerging social and mating systems of different species give rise to different benefits of investment in paternal care. Paternal care should have evolved in relation to the frequency of losing paternities to other males. Hence, in species living in one-male systems with little opportunity for female extra-pair copulations, paternal care should be more common than in those species living in multi-male groups. The guinea pigs (Caviinae) comprise closely related species exhibiting different social organizations and mating systems. The amount of paternal behaviour and offspring-directed aggression was investigated in three species kept under laboratory conditions: the polygynous Cavia aperea, the promiscuous Galea musteloides and a newly described monogamous species (Galea monasteriensis sp. nov.). All animals were kept in groups of one adult male and one adult female with their non-weaned offspring. Cavia aperea as well as G. monasteriensis males showed a high incidence of paternal behaviour, which consisted primarily of playing with offspring and grooming them. In contrast, G musteloides males never engaged in paternal behaviour but directed more aggressive behaviour towards their offspring. Mating with multiple partners and multiple paternities are common in G musteloides whereas in the former two species there is a much higher certainty of paternity. We conclude that paternal behaviour in guinea pigs probably co-evolved in alignment with the certainty of paternity that males of a species encounter under natural conditions.
Anja Guenther - One of the best experts on this subject based on the ideXlab platform.
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within family environment and cross fostering stress affect behavior and physiology in wild cavies Cavia aperea
Frontiers in Psychology, 2020Co-Authors: Sabine Kraus, Anja Guenther, Fritz TrillmichAbstract:Stability of personality traits is well documented for a wide variety of animals. However, previous results also suggest that behavioural phenotypes are plastic during early ontogeny and can be adaptively shaped to the social environment. In cavies (Cavia aperea), it has already been documented that the size at birth relative to siblings (size rank) greatly influences various behavioural and physiological traits that last at least until independence. The aim of the current study was (1) to investigate if behavioural and physiological differences between pups of the same litter persist until after independence and influence development long-lasting, (2) to determine the potential plasticity in response to changes in the early within-family environment by cross-fostering pups either to the same, a lower, or a higher size rank in a foster-family. We measured three behavioural traits (number of interactions with a novel object, distance moved in an open field, struggle docility) and two physiological traits (resting metabolic rate and basal cortisol levels). We predicted that cross-fostering into a litter where pups occupy the same size rank would not change the expression of traits. Cross-fostering to a different size rank should not influence the expression of traits if repeatability measures indicate low plasticity. Alternatively, if the traits are plastic, animals should adjust trait expression to fit with the size rank occupied in the foster litter. Initial differences in struggle docility, distance moved in an open field and in baseline cortisol concentration between pups of different size-ranks did not remain stable beyond independence. In addition, we found remarkable plasticity of the measured traits in response to cross-fostering to the same, a smaller or larger size-rank, suggesting that differences between pups are more the result of social constraints leading to adaptive shaping of individual phenotypes within a family. We also found a significant influence of the cross-fostering procedure itself. Cross-fostered individuals were less bold, grew slower and showed elevated resting metabolic rates. This finding suggests a cautious interpretation of previous cross-fostering studies and stresses the need for proper control groups to reliably separate the effect of cross-fostering per se from those induced by an experimental treatment.
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effect of season on reproductive behaviors and fertilization success in cavies Cavia aperea
Theriogenology, 2018Co-Authors: Romy Hribal, Kathrin Rübensam, Katarina Jewgenow, Sandra Bernhardt, Anja GuentherAbstract:Abstract Finding the optimal timing for breeding is crucial for small mammals to ensure survival and maximize lifetime reproductive success. Species living in temperate regions therefore often restrict breeding to seasons with favorable food and weather conditions. Although caviomorph rodents such as guinea pigs are described as non-seasonal breeders, a series of recent publications has shown seasonal adaptations in litter size, offspring birth mass and maternal investment. Here, we aim to test if seasonal patterns of litter size variation found in earlier studies, are mediated by seasonal differences in female estrus length, fertilization rate and mating behavior. The female estrus period was longer in fall compared to all other seasons (p
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life history trade offs are they linked to personality in a precocial mammal Cavia aperea
Biology Letters, 2018Co-Authors: Anja GuentherAbstract:Life-history trade-offs are predicted to contribute to the maintenance of personality variation. Individuals with ‘fast’ lifestyles should develop faster, reproduce earlier and exhibit more risky behaviours. Evidence for such predicted links, however, remains equivocal. Here, I test how growth rate, timing of maturation, litter size and maternal effort correlate with exploration, boldness, fearlessness, docility and escape latency. I found several links that were predicted by recent theory while others were against theoretical predictions, e.g. fast-growing individuals were more fearful. Thus, while I found personality to be integrated with life history, I cannot fully support recent hypotheses aiming to explain such behaviour–life-history associations.
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blastocyst recovery and multifactorial gene expression analysis in the wild guinea pig Cavia aperea
Theriogenology, 2016Co-Authors: Romy Hribal, Anja Guenther, Kathrin Rübensam, Katarina JewgenowAbstract:The expression of specific developmentally important genes in preimplantation embryos is an accepted marker for unraveling the influence of single factors in studies that are mostly related to artificial reproduction techniques. Such studies, however, often reveal high levels of heterogeneity between single embryos, independently of the influence of factors of interest. A possible explanation for this variation could be the large variety of physiological and environmental factors to which early embryos are exposed and their ability to react to them. Here, we investigated several potentially important parameters of development at the same time, in blastocysts of the wild guinea pig (Cavia aperea) generated in vivo after natural mating. The optimal time for flushing fully developed blastocysts was between 123 and 126 hours after mating. The abundance of POU5F1 (P = 0.042), BAX (P < 0.001), SLC2A1 (P = 0.017), and DNMT3A (P < 0.001) mRNA changed significantly over time after mating. The number of sibling embryos present influenced STAT3 levels significantly (P = 0.02). Levels of BAX and POU5F1 were significantly affected by season (P = 0.03 and 0.04). The temporal pattern of SLC2A1 levels was significantly altered both after feeding a protein-deficient diet (P = 0.04) and temperature treatment (P = 0.04) of the sire. In addition, the identity of the father had a significant influence on POU5F1 (P = 0.049) and STAT3 (P < 0.001) mRNA abundances. These data report that the expression of specific genes in early embryos reflects the entire heterogeneity of their surroundings and that it is a plastic reaction toward a multifactorial environment.
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Blastocyst recovery and multifactorial gene expression analysis in the wild guinea pig (Cavia aperea)
Theriogenology, 2016Co-Authors: Romy Hribal, Anja Guenther, Kathrin Rübensam, Katarina JewgenowAbstract:The expression of specific developmentally important genes in preimplantation embryos is an accepted marker for unraveling the influence of single factors in studies that are mostly related to artificial reproduction techniques. Such studies, however, often reveal high levels of heterogeneity between single embryos, independently of the influence of factors of interest. A possible explanation for this variation could be the large variety of physiological and environmental factors to which early embryos are exposed and their ability to react to them. Here, we investigated several potentially important parameters of development at the same time, in blastocysts of the wild guinea pig (Cavia aperea) generated in vivo after natural mating. The optimal time for flushing fully developed blastocysts was between 123 and 126 hours after mating. The abundance of POU5F1 (P = 0.042), BAX (P
Sylvia Kaiser - One of the best experts on this subject based on the ideXlab platform.
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photoperiodic effects on reproductive development in male cavies Cavia aperea
Physiology & Behavior, 2014Co-Authors: Anja Guenther, Mona Dersen, Rupert Palme, Sylvia Kaiser, Fritz TrillmichAbstract:Abstract Age at maturity is a particularly important life history parameter, as it predicts potential life time reproductive success in many small mammal species. Animals should therefore optimize the timing of maturation by reacting to environmental stimuli that predict future environmental conditions. Photoperiod often reliably predicts ecological conditions. Animals born into a photoperiod indicating favorable conditions (spring, summer) may mature earlier and at a lower weight than animals born into conditions indicating unfavorable conditions (autumn, winter). So far most work was done on small, altricial rodent species and we still lack knowledge about their precocial relatives. Precocial animals are born much further developed than altricials and might show less plasticity in their ontogenetic trajectory than the latter. We tested the influence of photoperiod simulated by increasing (spring) or decreasing (autumn) light in climate chambers on important life history parameters in a medium sized rodent, the highly precocial cavy ( Cavia aperea ). We wanted to determine whether photoperiod influences timing of maturation and early growth in male cavies and whether patterns of testosterone in blood are reflected by patterns of testosterone metabolites in feces. Males born into simulated spring grew faster and matured at an earlier age than males born into simulated autumn conditions. Patterns of testosterone in blood correlated with testosterone metabolites measured in feces. Male cavies strongly react to predictive photoperiod cues by adjusting growth and timing of maturation as we found previously for females, corroborating the importance of seasonal cues for adjustments of life history.
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Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs
Frontiers in Zoology, 2010Co-Authors: Lars Lewejohann, Norbert Sachser, Thorsten Pickel, Sylvia KaiserAbstract:Background Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig ( Cavia aperea f. porcellus ), starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea . Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment. In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Results Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. Conclusion The results demonstrate that domestic guinea pigs do not at all perform worse than their wild relatives in tests of spatial learning abilities. Yet, the contrary seems to be true. Hence, artificial selection and breeding did not lead to a cognitive decline but rather to an adaptation to man-made environment that allows solving the task more efficiently.
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puberty in female cavies Cavia aperea is affected by photoperiod and social conditions
Physiology & Behavior, 2009Co-Authors: Fritz Trillmich, Sylvia Kaiser, Birte Mueller, Jana KrauseAbstract:In many environments, photoperiod is a reliable predictor of ecological conditions. Such predictability generally declines towards low latitudes as the yearly cycle becomes less marked. It has been claimed that photoperiodic effects are small in cavies and guinea pigs that reproduce throughout the year. We here investigated photoperiodic influences on the onset of puberty in female cavies (Cavia aperea) and show that photoperiod exerts a major influence. Female pups kept in groups of two matured at about 47 days when born into lengthening (from 10:14 to 12.5:11.5 L:D) and 79 days when born into shortening day length (from 145:9.5 to 12:12 L:D) and kept under identical short day conditions after weaning on day 20 of life (12.25:11.75 L:D). As shown previously, social conditions, especially the presence of an adult male, proved important modifiers of the onset of maturity in females. Differential stress cannot be responsible for the social effects on puberty as social conditions did not affect cortisol levels in young females. We conclude that photoperiod plays an important role in gearing the onset of cavy reproduction to the seasons and that specific male stimuli rather than unspecific effects of stressors accelerate female maturation. (C) 2008 Elsevier Inc. All rights reserved.
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social organization predicts nature of infant adult interactions in two species of wild guinea pigs Cavia aperea and galea monasteriensis
Journal of Comparative Psychology, 2006Co-Authors: Michael B Hennessy, Sylvia Kaiser, Gesa Neisen, Katie L Bullinger, Norbert SachserAbstract:The authors compared interactions of infants with mothers and unfamiliar females in a novel environment in 2 caviomorph rodent species: the harem-living Cavia aperea, the probable progenitor of the domestic guinea pig; and the pair-living Galea monasteriensis. In C. aperea, interactions with mothers and unfamiliar females were largely similar; in G. monasteriensis, interactions with the mother, but not unfamiliar female, were characterized by physical closeness and sociopositive behavior. In G. monasteriensis, plasma cortisol levels were lower when with the mother than when with the unfamiliar female. Results are consistent with the species' social organizations and suggest that behavioral interactions of pups with mothers and other females in domestic guinea pigs reflect primarily the social organization of the progenitor species rather than domestication.
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Social Organization Predicts Nature of Infant–Adult Interactions in Two Species of Wild Guinea Pigs ( Cavia aperea and Galea monasteriensis )
Journal of Comparative Psychology, 2006Co-Authors: Michael B Hennessy, Sylvia Kaiser, Gesa Neisen, Katie L Bullinger, Norbert SachserAbstract:The authors compared interactions of infants with mothers and unfamiliar females in a novel environment in 2 caviomorph rodent species: the harem-living Cavia aperea, the probable progenitor of the domestic guinea pig; and the pair-living Galea monasteriensis. In C. aperea, interactions with mothers and unfamiliar females were largely similar; in G. monasteriensis, interactions with the mother, but not unfamiliar female, were characterized by physical closeness and sociopositive behavior. In G. monasteriensis, plasma cortisol levels were lower when with the mother than when with the unfamiliar female. Results are consistent with the species' social organizations and suggest that behavioral interactions of pups with mothers and other females in domestic guinea pigs reflect primarily the social organization of the progenitor species rather than domestication.
Susanne Huber - One of the best experts on this subject based on the ideXlab platform.
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Sex-specific impact of prenatal stress on growth and reproductive parameters of guinea pigs
Journal of Comparative Physiology B, 2012Co-Authors: Hanna Schopper, Rupert Palme, Teresa Klaus, Susanne HuberAbstract:Body condition and reproductive maturation are parameters of reproductive success that are influenced by sexual hormones rising in the circulation during the time of puberty. Various endocrine systems can be programmed by conditions experienced during early life. Stress for instance is supposed to be capable of influencing fetal development, leading to adjustments of offspring’s later physiology. We examined whether prenatal stress (induced by exposure to strobe light) during early- to mid-gestation was capable of affecting later reproductive parameters in guinea pigs ( Cavia aperea f . porcellus ). Therefore, we measured the levels of testosterone and progesterone from the age of day 12–124 in prenatally stressed (PS, n = 20) and unaffected control animals ( n = 24). Furthermore, we determined the timing of puberty and growth. Body weight development revealed significantly faster growth in PS females compared to control animals. The onset of first estrus was slightly earlier in PS females, however not significantly so. Cycle lengths and levels of progesterone differed between groups over the course of time with higher progesterone levels and more constant cycles among PS females compared to control females who displayed marked differences between first and subsequent cycles. Levels of testosterone did not differ between groups. We conclude that prenatal stress accelerates growth and maturity in females, but not in males.
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effects of prenatal stress on hypothalamic pituitary adrenal hpa axis function over two generations of guinea pigs Cavia aperea f porcellus
General and Comparative Endocrinology, 2012Co-Authors: Hanna Schopper, Rupert Palme, Susanne HuberAbstract:Prenatal stress can alter hypothalamic–pituitary–adrenal axis function with potential consequences for later life. The aim of our study was to examine in guinea pigs (Cavia aperea f. porcellus) the effects of stress experienced during F0 pregnancy on glucocorticoid levels in plasma and feces, as well as challenge performance, in F1 offspring (n = 44) and fecal glucocorticoid levels in F2 offspring (n = 67). F1 animals were either born to F0 dams that had been stressed with strobe light during early to mid pregnancy, resulting in a short term increase but long-term down-regulation of maternal glucocorticoid levels, or to undisturbed F0 dams. The same stressor was used as a challenge for F1 offspring at age 26 days and around 100 days. Basal plasma cortisol concentrations during early F1 development, as well as overall glucocorticoid levels at challenge tests, were lower in F1 animals that were prenatally stressed than in control animals. Fecal cortisol metabolites were initially at lower levels in prenatally stressed F1 animals, relative to control animals, but shifted to higher levels around day 68, with an additional sex difference. Effects were also seen in the F2 generation, as male but not female offspring of prenatally stressed F1 animals had significantly higher levels of cortisol metabolites in feces after weaning. We conclude that stress exposure of F0 dams resulted in lower basal glucocorticoid levels in F1 offspring during the pre-pubertal phase and during stress exposure, but higher glucocorticoid levels in post-adolescent F1 animals. Also in males of F2 generation effects of stress exposure of F0 dams were detected.
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chronic stress in pregnant guinea pigs Cavia aperea f porcellus attenuates long term stress hormone levels and body weight gain but not reproductive output
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2011Co-Authors: Hanna Schopper, Rupert Palme, Susanne HuberAbstract:Stress, when extreme or chronic, can have a negative impact on health and survival of mammals. This is especially true for females during reproduction when self-maintenance and investment in offspring simultaneously challenge energy turnover. Therefore, we investigated the effects of repeated stress during early- and mid-gestation on the maternal stress axis, body weight gain and reproductive output. Female guinea pigs (Cavia aperea f. porcellus, n = 14) were either stressed (treatment: exposure to strobe light in an unfamiliar environment on gestational day -7, 0, 7, 14, 21, 28, 35, 42) or left completely undisturbed (control) throughout pregnancy. Females of both groups received the same respective diets, and reproductive parameters were evaluated upon parturition. Additionally, hormonal data were obtained from blood and feces. The stress exposure induced a significant increase in plasma cortisol concentrations during the afternoon. In contrast to this short-term response in plasma cortisol concentrations, we found no significant differences in the levels of cortisol metabolites in feces collected after stress exposure between groups and even significantly decreased levels of fecal cortisol metabolites on non-stress days over time in treatment females. Among treatment females, gain in body weight was attenuated over gestation and body weight was lower compared to control females during lactation, especially in cases of large litter sizes. No differences could be seen in the reproductive parameters. We conclude that repeated stress exposure with strobe light during early- and mid-gestation results in a down-regulation of the hypothalamic–pituitary–adrenal axis and lower weight gain in treatment females, but has no effect on reproductive output.
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the effects of early environmental conditions on the reproductive and somatic development of juvenile guinea pigs Cavia aperea f porcellus
General and Comparative Endocrinology, 2008Co-Authors: Barbara Bauer, Irene Womastek, John Dittami, Susanne HuberAbstract:Little is known about the effects of the early environment on the development of non-seasonally reproducing species like the domestic guinea pig (Cavia aperea f. porcellus). Although guinea pigs reproduce throughout the year, there is evidence for environmental sensitivity of their reproductive physiology. To investigate the sensitivity of juvenile body weight and puberty to differences in the prenatal and early postnatal environment, subjects were exposed to either of two experimental conditions mimicking seasonal variation: a long photoperiod with 25 °C ambient temperature (“LD/25 °C”), or a short photoperiod with 15 °C (“SD/15 °C”). Mean body weight of F1-males from LD/25 °C-conditions was higher than that of SD/15 °C-males during the whole pubertal period, although the difference was significant only during the early growth phase. Testosterone concentrations also differed significantly between the two treatment groups, pointing to an earlier pubertal onset in LD/25 °C- than SD/15 °C-males. In F1-females, treatment effects on body weight or age at first estrus were absent. This indicates that the somatic and reproductive development is more sensitive to early photoperiod and temperature conditions in male than female guinea pigs, and that other environmental factors may also play a crucial role for reproductive maturation in this species.