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Tonische immobiliteit (TI) is een niet-aangeleerde en omkeerbare toestand van motorische onbeweeglijkheid die bij verscheidene terrestrische en aquatische diersoorten, zoals haaien, kan worden uitgelokt. TI is van oorsprong een natuurlijk gedrag dat bij haaien kan worden uitgelokt door plaatselijke druk uit te oefenen ter hoogte van de vinnen en de dieren op de rug te draaien, waarna ze een verslapping van de spiertonus vertonen en tijdelijk niet meer reageren op omgevingsstimuli. Deze toestand kan mogelijk een effect hebben op de fysiologie van de dieren. TI zou bij haaien de ventilatie-efficiëntie verminderen en bijgevolg verscheidene bloedparameters beïnvloeden, stressrespons induceren en de osmolariteit van het bloed verstoren. Desalniettemin kent TI bij haaien wetenschappelijke en diergeneeskundige toepassingen bij (klinisch) onderzoek, bloedafname en wondbehandeling. Tonische immobiliteit bij haaien is echter een enigmatisch fenomeen en verdient verder interdisciplinair onderzoek. Tonic immobility (TI) is an inherited and reversible status of motoric immobility that can be provoked in a variety of terrestrial and aquatic animal species, including sharks. In sharks, this behavior, which is originally natural behavior, can be induced by putting external pressure on the fins and turning the animal on its back, after which the sharks will display reduced muscle tone and will temporarily not respond to environmental stimulation. It can be expected that this state has an effect on the physiology of the animal. In sharks, it can induce lowered ventilation efficiency with impact on blood parameters, it can cause a stress response and disrupt the osmolarity of the blood. Nonetheless, this TI state in sharks has its applications in scientific and veterinary (clinical) research, blood sampling and wound treatment. However, tonic immobility in sharks remains an enigmatic phenomenon that should be studied in detail using an interdisciplinary approach.

Maternal effects can adaptively modulate offspring developmental trajectories in variable but predictable environments. Hormone synthesis is sensitive to environmental factors, and maternal hormones are thus a powerful mechanism to transfer environmental cues to the next generation. Birds have become a key model for the study of hormone-mediated maternal effects because the embryo develops outside the mother's body, facilitating the measurement and manipulation of prenatal hormone exposure. At the same time, birds are excellent models for the integration of both proximate and ultimate approaches, which is key to a better understanding of the evolution of hormone-mediated maternal effects. Over the past two decades, a surge of studies on hormone-mediated maternal effects has revealed an increasing number of discrepancies. In this review, we discuss the role of the environment, genetic factors and social interactions in causing these discrepancies and provide a framework to resolve them. We also explore the largely neglected role of the embryo in modulating the maternal signal, as well as costs and benefits of hormone transfer and expression for the different family members. We conclude by highlighting fruitful avenues for future research that have opened up thanks to new theoretical insights and technical advances in the field. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.

During avian embryonic development, thyroid hormones (THs) coordinate the expression of a multitude of genes thereby ensuring that the correct sequence of cell proliferation, differentiation and maturation is followed in each tissue and organ. Although THs are needed from the start of development, the embryonic thyroid gland only matures around mid-incubation in precocial birds and around hatching in altricial species. Therefore, maternal THs deposited in the egg yolk play an essential role in embryonic development. They are taken up by the embryo throughout its development, from the first day till hatching, and expression of TH regulators such as distributor proteins, transporters, and deiodinases in the yolk sac membrane provide the tools for selective metabolism and transport starting from this level. TH receptors and regulators of local TH availability are expressed in avian embryos in a dynamic and tissue/cell-specific pattern from the first stages studied, as shown in detail in chicken. Maternal hyperthyroidism via TH supplementation as well as injection of THs into the egg yolk increase TH content in embryonic tissues while induction of maternal hypothyroidism by goitrogen treatment results in a decrease. Both increase and decrease of maternal TH availability were shown to alter gene expression in early chicken embryos. Knockdown of the specific TH transporter monocarboxylate transporter 8 at early stages in chicken cerebellum, optic tectum, or retina allowed to reduce local TH availability, interfering with gene expression and confirming that development of the central nervous system (CNS) is highly dependent on maternal THs. While some of the effects on cell proliferation, migration and differentiation seem to be transient, others result in persistent defects in CNS structure. In addition, a number of studies in both precocial and altricial birds showed that injection of THs into the yolk at the start of incubation influences a number of parameters in posthatch performance and fitness. In conclusion, the data presently available clearly indicate that maternal THs play an important role in avian embryonic development, but how exactly their influence on cellular and molecular processes in the embryo is linked to posthatch fitness needs to be further explored. ispartof: Frontiers In Endocrinology vol:10 ispartof: location:Switzerland status: published

INTRODUCTION In animals, coat color is often arranged in periodic motifs that vary widely, from striped to spotted patterns. These intricate designs have long fascinated developmental biologists and mathematicians alike. What are the mechanisms underlying the formation of periodic patterns and shaping their diversity? Spatial organization in the developing skin involves prepatterns that precede the color pattern. Self-organizing events have long been thought to act upstream of prepatterns (e.g., through molecular diffusion or pigment cell interaction). Changes in both of these molecular and cellular events may contribute to periodic pattern variation. However, periodic patterns are highly reproducible within species and display specific orientation and periodicity, which suggests that they also rely on preexisting spatial reference. RATIONALE Documenting phenotype diversity constitutes a promising framework for the prediction of such spatial landmarks, comparable to mathematical modeling strategies. We surveyed variation in the transient periodic pattern visible in juvenile birds of the galliform group, in which longitudinal stripes are organized in a black-yellow-black sequence in the dorsal region. RESULTS By comparing the striped pattern for 10 galliform bird species, we showed that the width of each stripe varied and that their number increased with dorsum size. In contrast, their absolute positions were comparable. We analyzed pigment appearance in the embryonic skin of five representative species and showed that the periodic striped pattern results from the timely production of yellow coloration at specific locations. This yellow-production pulse was not triggered by a certain stage of feather growth or by dynamics of feather follicle production across the dorsum. However, it was linked to the early expression of agouti . This well-known pigmentation gene displayed a composite expression pattern in longitudinal bands whose width and position correlated with that of yellow stripes in each species. To test agouti ’s role, we used a functional approach by exploiting mutant strains of quails: The increase (in the Fawn strain) or decrease (in the recessive black strain) of agouti expression levels respectively led to wider or narrower yellow stripes. Comparing pigment distribution across feathers between these gain- or loss-of-function mutants and wild-type quails showed that agouti controls stripe width by adjusting the duration of the yellow-production pulse in a dose-dependent manner. Both the position of agouti -expressing bands and that of yellow stripes did not change in mutant quails. To identify the origin of signals controlling localized agouti expression and setting the position of yellow stripes, we performed heterospecific grafting experiments: Embryonic tissues from donor quails were transplanted into pheasant hosts. We found that after transplanting somites (from which dermal cells originate), chimeras locally displayed quail-like expression of agouti in the developing skin. Long-term experiments showed that hosts displayed a striped color pattern typical of the donor at the level of the graft. Such changes were not observed when the neural tube (from which pigment-producing cells originate) was grafted. These results showed that the somitic mesoderm autonomously instructs agouti expression and consequently the position of yellow stripes. CONCLUSION We conclude from this work that the galliform striped pattern is achieved in a two-step mechanism. The somite provides positional information to the developing dermis; this controls the position of agouti expression in a prepattern that foreshadows yellow stripes. Their width is then refined by agouti , which locally controls yellow production in a dose-dependent manner. This sequential organization of space, combining early landmarks and local mechanisms, may govern the formation (and thus constrain the evolution) of many periodic patterns.

Animal personality traits emerge developmentally from the interaction of genetic and early environmental factors. Maternal hormones, such as androgens (testosterone, T and androstenedione, A4), transferred to embryos and egg yolks may simultaneously organize multiple behavioural and physiological traits. Whereas previous studies demonstrated an association between the mother's personality and yolk androgen levels, the independent effects of the male partner's personality and pair combination are unknown. We test this association using an ecological model species for personality research, the great tit (Parus major) using multiple approaches: 1) a wild population, 2) a randomly-mated captive population, and 3) an experimental study with (dis)assortatively mated pairs from lines selected for fast exploration/boldness or slow exploration/shyness. Egg androgen concentrations were associated with variation in female personality traits, and the experimental data suggested that this is independent of male personality: experimental females from slow-shy line tended to have higher egg T concentrations than females from the fast-bold line, with no effect of male personality. Shy females from the wild population had higher egg A4 concentration than bold females. However, in the correlative data yolk hormones were linked with male personality, as well as the interaction between female and male traits and yolk androgen levels: Male handling responsiveness correlated negatively with egg A4 concentration in wild birds. In randomly-mated birds, pairs that were mated assortatively for personality had lower egg T concentrations than disassortatively mated pairs. Given that egg androgens are known mediators of avian personality, our results suggest that maternal hormones might contribute to the heritability of personality, may be sensitive to the social context of mating, and act as key drivers of individual differences. This article is protected by copyright. All rights reserved.

Living systems exhibit non-randomly organized biochemical, physiological, and behavioral processes that follow distinctive patterns. In particular, animal behavior displays both fractal dynamics and periodic rhythms yet the relationship between these two dynamic regimens remain unexplored. Herein we studied locomotor time series of visually isolated Japanese quails sampled every 0.5 s during 6.5 days (>106 data points). These high-resolution, week-long, time series enabled simultaneous evaluation of ultradian rhythms as well as fractal organization according to six different analytical methods that included Power Spectrum, Enright, Empirical Mode Decomposition, Wavelet, and Detrended Fluctuation analyses. Time series analyses showed that all birds exhibit circadian rhythms. Although interindividual differences were detected, animals presented ultradian behavioral rhythms of 12, 8, 6, 4.8, 4 h and/or lower and, irrespective of visual isolation, synchronization between these ultradian rhythms was observed. Moreover, all birds presented similar overall fractal dynamics (for scales â30 s to >4.4 h). This is the first demonstration that avian behavior presents fractal organization that predominates at shorter time scales and coexists with synchronized ultradian rhythms. This chronobiological pattern is advantageous for keeping the organism's endogenous rhythms in phase with internal and environmental periodicities, notably the feeding, light-dark and sleep-wake cycles. Fil: Guzmán, Diego Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; Argentina. University Aarhus; Dinamarca Fil: Flesia, Ana Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina Fil: Aon, Miguel A.. University Johns Hopkins; Estados Unidos Fil: Pellegrini, Stefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; Argentina Fil: Marin, Raul Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; Argentina Fil: Kembro, Jackelyn Melissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; Argentina

The Cape gannet Morus capensis, a large fish-eating seabird, is endemic to southern Africa. To study the energetics of nestling growth, we used the doubly labeled water technique to measure field metabolic rate (FMR) of nestlings, from hatchings to large partly feathered chicks (n =17) at Malgas Island, Saldanha Bay, South Africa. At the same time, the growth rate of a large sample of chicks was measured (n = 338). These data, together with literature values on resting metabolic rate and body composition, were used to construct and partition the nestling energy budget. Nestling FMR (kJ d(-1)) increased with body mass according to FMR = 1.23m(0.923), r(2) = 0.944. Mass-specific FMR (FMRratio; kJ d(-1) g(-3/4)) was independent of chick age (r(2) = 0.20, P > 0.05); mean mass-specific FMR was 4.11 +/- 1.28, n = 17. Peak daily-metabolized energy (DME), which represents the maximum rate at which parents must supply their nestlings, occurred at age 71 d and was 2,141 kJ d(-1). Between the ages 51 and 92 d (43% of the fledging period), the DME of Cape gannet chicks was equal to or surpassed 90% of adult FMR at the nest. Energy demand during this period of peak DME represented 58% of the total metabolized energy, which was estimated at 150.1 MJ for an average chick during a 97-d period, from hatching to fledging. Sensitivity analysis of the energy budget indicated that the model was robust; the biggest source of error (+15%) was for the mass-FMR equation used in the model.

Genetic evaluations in dual-purpose quails (Coturnix coturnix) have demonstrated that overall genetic gains in a breeding program are achieved not only based on a specific trait, but on several. The most common technique to use all this information is the selection index. Another alternative may be the canonical-correlation analysis applied to selection index. There is, however, a lack of studies using canonical correlation in quails. Hence, the objectives of this study were to apply canonical-correlation analysis to estimate the relationship of nine traits and to compare genetic gains obtained by this methodology to desired-gain selection index in three lines of quails. Data for three lines of layer quails consisted of body weight at 28 days (W28), egg weight (EW), age at first egg (APE) and egg production at 30, 60, 90, 120, 150 and 180 days after onset of lay. Two sets of traits were established: the first one contained predictor variables (W28, EW and APE) and the second one contained variables related to egg production. A selection index was constructed using the standardized coefficients of canonical covariates as weighting factors when a given canonical correlation was significant. We constructed two desired-gain selection indices: DG-SI1 and DG-S12. The difference between them is that DG-S12 had a desired gain for body weight set to 0. The estimated canonical correlations were as follows: 0.811, 0.058 and 0.003 for the yellow, 0.821, 0.181 and 0.076 for the red, and 0.825, 0.117 and 0.038 for the blue line. Only the first pair of canonical variates was significant (P

The present study investigated the long-term consistency of individual differences in dairy cattles' responses in tests of behavioural and hypothalamo-pituitary-adrenocortical (HPA) axis reactivity, as well as the relationship between responsiveness in behavioural tests and the reaction to first milking. Two cohorts of heifer calves, Cohorts 1 (N = 25) and 2 (N = 16), respectively, were examined longitudinally from the rearing period until adulthood. Cohort 1 heifers were subjected to open field (OF), novel object (NO), restraint, and response to a human tests at 7 months of age, and were again observed in an OF test during first pregnancy between 22 and 24 months of age. Subsequently, inhibition of milk ejection and stepping and kicking behaviours were recorded in Cohort 1 heifers during their first machine milking. Cohort 2 heifers were individually subjected to OF and NO tests as well as two HPA axis reactivity tests (determining ACTH and/or cortisol response profiles after administration of exogenous CRH and ACTH, respectively) at 6 months of age and during first lactation at approximately 29 months of age. Principal component analysis (PCA) was used to condense correlated response measures (to behavioural tests and to milking) within ages into independent dimensions underlying heifers' reactivity. Heifers demonstrated consistent individual differences in locomotion and vocalisation during an OF test from rearing to first pregnancy (Cohort 1) or first lactation (Cohort 2). Individual differences in struggling in a restraint test at 7 months of age reliably predicted those in OF locomotion during first pregnancy in Cohort 1 heifers. Cohort 2 animals with high cortisol responses to OF and NO tests and high avoidance of the novel object at 6 months of age also exhibited enhanced cortisol responses to OF and NO tests at 29 months of age. Measures of HPA axis reactivity, locomotion, vocalisation and adrenocortical and behavioural responses to novelty were largely uncorrelated, supporting the idea that stress responsiveness in dairy cows is mediated by multiple independent underlying traits. Inhibition of milk ejection and stepping and kicking behaviours during first machine milking were not related to earlier struggling during restraint, locomotor responses to OF and NO tests, or the behavioural interaction with a novel object. Heifers with high rates of OF and NO vocalisation and short latencies to first contact with the human at 7 months of age exhibited better milk ejection during first machine milking. This suggests that low underlying sociality might be implicated in the inhibition of milk ejection at the beginning of lactation in heifers. (C) 2013 Elsevier B.V. All rights reserved.

In many bird populations, variation in the timing of reproduction exists but it is not obvious how this variation is maintained as timing has substantial fitness consequences. Daily energy expenditure (DEE) during the egg laying period increases with decreasing temperatures and thus perhaps only females that can produce eggs at low energetic cost will lay early in the season, at low temperatures. We tested whether late laying females have a higher daily energy expenditure during egg laying than early laying females in 43 great tits (Parus major), by comparing on the same day the DEE of early females late in their laying sequence with DEE of late females early in their egg laying sequence. We also validated the assumption that there are no within female differences in DEE within the egg laying sequence. We found a negative effect of temperature and a positive effect of female body mass on DEE but no evidence for differences in DEE between early and late laying females. However, costs incurred during egg laying may have carry-over effects later in the breeding cycle and if such carry-over effects differ for early and late laying females this could contribute to the maintenance of phenotypic variation in laying dates.

Many local breeds are currently at risk because of replacement by a limited number of specialized commercial breeds. Concurrently, for many breeds, allelic diversity within breeds declines because of inbreeding. Gene banking of germplasm may serve to secure the breeds and the alleles for any future use, for instance to recover a lost breed, to address new breeding goals, to support breeding schemes in small populations to minimize inbreeding, and for conservation genetics and genomics research. Developments in cryobiology and reproductive technology have generated several possibilities for preserving germplasm in farm animals. Furthermore, in some mammalian and bird species, gene banking of material is difficult or impossible, requiring development of new alternative methods or improvement of existing methods. Depending on the species, there are interesting possibilities or research developments in the use of epididymal spermatozoa, oocytes and embryos, ovarian and testicular tissue, primordial germ cells, and somatic cells for the conservation of genetic diversity in farm- and other animal species. Rapid developments in genomics research also provide new opportunities to optimize conservation and sampling strategies and to characterize genome-wide genetic variation. With regard to gene banks for farm animals, collaboration between European countries is being developed through a number of organizations, aimed at sharing knowledge and expertise between national programmes. It would be useful to explore further collaboration between countries, within the framework of a European gene banking strategy that should minimize costs of conservation and maximize opportunities for exploitation and sustainable use of genetic diversity.

1. Climate change has caused a phenological mismatch between the timing of reproduction and the local food peak in many bird species. Late breeding birds therefore experience reduced food availability during chick rearing and are thus predicted to have an increased energy expenditure. Observational studies, however, show mixed results, perhaps because they compare energy expenditure across rather than within individuals at different levels of food availability.2. In a cross foster experiment, we measured daily energy expenditure (DEE) twice within individuals during chick feeding (when chicks were 6 and 14 days old) for 28 free-living female great tits (Parus major). To avoid confounding effects of chick age, these females reared on both occasions a standardized foster brood of eight 10-day-old chicks during the 24-h measuring period. For all birds, food availability declined between the two measurements.3. We show that DEE during chick feeding increased within females when food availability decreased. Variation in DEE within females is partly explained by brood visit rates, food availability and temperature.4. DEE during chick feeding could be affected by the investment in previous stages of the reproductive attempt. However, energy expenditure during chick feeding was not correlated to energy expenditure during egg laying, measured in these same females.5. Understanding of energetic costs during all phases of the reproductive cycle is important to forecast the consequences of climate warming on timing of reproduction.

The propensity to develop feather pecking (FP) has a genetic component and has been related to fear responses in laying hens. A convenient test measuring the fear response might therefore be used to identify hens with a stronger propensity to develop FP. However, genetic origin and age can influence the relation between fear response and FP. The present study investigated the use of a novel object test in the home cage as predictor of FP in six lines of laying hens from Rhode Island Red origin and six lines from White Leghorn origin at adult age. Incidence of FP was assessed by scoring feather damage at back, rump and belly at 35, 43, 51, 63 and 69 weeks of age. A novel object test, measuring fear response to a rod, was performed at 23, 46 and 69 weeks of age. For RIR lines, a stronger fear response at 23 weeks was related to decreased feather damage at 51 weeks and for both RIR and WL lines stronger fear responses at 46 weeks were related to increased feather damage at 51 weeks. These results suggest that the relation between FP and fear response differs between ages and between Rhode Island Red and White Leghorn lines.

Assessing the behavioural adaptation of an animal to its environment is complex, notably because numerous criteria can be taken into consideration. A better understanding of the relationships between criteria, particularly between behavioural and physiological respon-ses, might help reduce the number of parameters required to assess animal welfare. The existence of relationships between behavioural and physiological responses of animals to potentially threatening situations has been suggested both by studies comparing animals reared in different environments and by those comparing animals with extreme genotypes. Moreover, the identification of coping styles in va-rious species has strengthened the idea that physiological and behavioural responses could be related, although the precise laws governing such relationships are still difficult to establish and generalise. Thus, considering the complexity of these relationships, it appears reasonable to consider these two groups of responses as partially independent and as giving complementary information about animal welfare. In the future, the development of complex trait analyses as well as investigation at the level of the brain should improve understanding of the relationships between physiological and behavioural responses

Female birds have been shown to manipulate offspring sex ratio. However, mechanisms of sex ratio bias are not well understood. Reduced feed availability and change in body condition can affect the mass of eggs in birds that could lead to a skew in sex ratio. We employed feed restriction in laying chickens (Gallus gallus) to induce a decrease in body condition and egg mass using 45 chicken hens in treatment and control groups. Feed restriction led to an overall decline of egg mass. In the second period of treatment (Days 9-18) with more severe feed restriction and a steeper decline of egg mass, the sex ratio per hen (proportion of male eggs) had a significant negative association with mean egg mass per hen. Based on this association, two groups of hens were selected from feed restriction group, that is, hens producing male bias with low egg mass and hens producing female bias with high egg mass with overall sex ratios of 0.71 and 0.44 respectively. Genomewide transcriptome analysis on the germinal disks of F1 preovulatory follicles collected at the time of occurrence of meiosis-I was performed. We did not find significantly differentially expressed genes in these two groups of hens. However, gene set enrichment analysis showed that a number of cellular processes related to cell cycle progression, mitotic/meiotic apparatus, and chromosomal movement were enriched in female-biased hens or high mean egg mass as compared with male-biased hens or low mean egg mass. The differentially expressed gene sets may be involved in meiotic drive regulating sex ratio in the chicken.

Female birds have been shown to manipulate offspring sex ratio. However, mechanisms of sex ratio bias are not well understood. Reduced feed availability and change in body condition can affect the mass of eggs in birds that could lead to a skew in sex ratio. We employed feed restriction in laying chickens (Gallus gallus) to induce a decrease in body condition and egg mass using 45 chicken hens in treatment and control groups. Feed restriction led to an overall decline of egg mass. In the second period of treatment (Days 9-18) with more severe feed restriction and a steeper decline of egg mass, the sex ratio per hen (proportion of male eggs) had a significant negative association with mean egg mass per hen. Based on this association, two groups of hens were selected from feed restriction group, that is, hens producing male bias with low egg mass and hens producing female bias with high egg mass with overall sex ratios of 0.71 and 0.44 respectively. Genomewide transcriptome analysis on the germinal disks of F1 preovulatory follicles collected at the time of occurrence of meiosis-I was performed. We did not find significantly differentially expressed genes in these two groups of hens. However, gene set enrichment analysis showed that a number of cellular processes related to cell cycle progression, mitotic/meiotic apparatus, and chromosomal movement were enriched in female-biased hens or high mean egg mass as compared with male-biased hens or low mean egg mass. The differentially expressed gene sets may be involved in meiotic drive regulating sex ratio in the chicken.

Two 1-year old Roulroul partridges (Rollulus rouloul), one male and one female, were presented because of eye problems and anorexia. Twenty of the 30 Roulroul partridges in the owner's collection had already died. The affected birds stopped eating, became thinner, and eventually died. Antibiotic treatment, which started because of the suspicion of a septicaemic process, was unsuccessful. At clinical examination of the two partridges it was found that in both birds, one eye ball was filled with a whitish yellow amorphous material and the other eye ball of the female showed a distinct corneal opacity. Both presented birds were euthanized. Necropsy revealed no significant abnormalities in addition to the eye lesions. Histology and immunohistochemistry of the female's eye revealed an infiltrate of T-lymphocytes corresponding to ocular lymphoma. Herpesvirus genus-specific PCR, followed by Sanger sequencing confirmed the presumptive diagnosis of Marek's disease in both birds. To our knowledge, this is the first confirmed case of infection with Gallid Herpesvirus 2 (Marek's disease virus) in partridges and the first case in this specific species.

Giant lampbrush chromosomes, which are characteristic of the diplotene stage of prophase I during avian oogenesis, represent a very promising system for precise physical gene mapping. We applied 35 chicken BAC and 4 PAC clones to both mitotic metaphase chromosomes and meiotic lampbrush chromosomes of chicken (Gallus gallus domesticus) and Japanese quail (Coturnix coturnix japonica). Fluorescence in situ hybridization (FISH) mapping on lampbrush chromosomes allowed us to distinguish closely located probes and revealed gene order more precisely. Our data extended the data earlier obtained using FISH to chicken and quail metaphase chromosomes 1-6 and Z. Extremely low levels of inter- and intra-chromosomal rearrangements in the chicken and Japanese quail were demonstrated again. Moreover, we did not confirm the presence of a pericentric inversion in Japanese quail chromosome 4 as compared to chicken chromosome 4. Twelve BAC clones specific for chicken chromosome 4p and 4q showed the same order in quail as in chicken when FISH was performed on lampbrush chromosomes. The centromeres of chicken and quail chromosomes 4 seem to have formed independently after centric fusion of ancestral chromosome 4 and a microchromosome.

The aim of the present study was to determine the degree of consistency of individual differences in behavioural responses of heifer calves over time and across different situations. Twenty-five Holstein Friesian heifer calves were individually subjected to the same set of four behavioural tests at 3, 16 and 29 weeks of age. The tests involved measuring the calves' responses to a stationary human, a novel object, an open field (novel environment), and to tethering restraint. Principal component analysis (PCA) of measures recorded at each age was used to identify independent dimensions underlying the calves' reactivity to these situations. The consistency of individual differences was established by ranking the behavioural scores and the scores of factors extracted by PCA and then estimating the correlations between the ranks of each individual calf at each of the test ages. At each age, PCA revealed four factors that could be labelled: "locomotion", "vocalisation", "interaction with a novel object", and "interaction with a human". Individual differences in 7 of 13 behavioural measures and in scores of all factors except "interaction with a human" were consistent between 16 and 29 weeks of age. Rank orders for scores of the factor labelled "interaction with a novel object" were significantly correlated across all three ages. Our results support the existence in calves of stable characteristics mediating reactivity to challenge. Multiple behavioural dimensions obtained with PCA suggest that behavioural responsiveness of calves to challenge is governed by a number of underlying factors rather than univariate phenomena, such as fearfulness or coping style. (C) 2003 Elsevier B.V. All rights reserved.

We examined whether low ambient temperatures influence foraging behavior of precocial Japanese quail chicks and alter the balance between investment in growth and thermogenic function. To test this, one group of chicks was exposed to 7 degreesC and one group to 24 degreesC during foraging throughout the developmental stage. Chicks adapted well to the temperatures through a high flexibility in behavior and physiological development. In response to cold, chicks shortened foraging bout lengths two- to sixfold, and increased cycle lengths (i.e. length of a brooding bout plus subsequent foraging bout), resulting in a decrease in total foraging time. Body temperature during foraging was lower in cold-exposed chicks but did not drop below 37.8 degreesC, suggesting that the direct cause to end a foraging bout was not body temperature. The metabolic rate of cold-exposed chicks was reduced by 48% to 60% when switching from foraging to brooding, which may be an important factor in determining foraging behavior of precocial chicks. Mass-specific food intake of the cold-exposed chicks exceeded that of warm chicks by 15%. Cold-exposed chicks doubled foraging efficiency to reach this intake during their reduced foraging time. Metabolic rates initially were similar in both groups, but increased rapidly and were elevated in cold-exposed chicks from 15 days of age onward. Growth rate initially was reduced in cold-exposed chicks, and exceeded growth of warm chicks only after 21 days of age. These results suggest that in response to cold, a shift occurs in the balance between growth rate and thermoregulatory function in favor of thermoregulatory function. (C) 2003 Elsevier Science Inc. All rights reserved.

Sampling bias is a key issue to consider when designing studies to address biological questions and its importance has been widely discussed in the literature. However, some forms of bias remain underestimated. We investigated the roosting decisions of free-living great tits utilizing nest-boxes in response to the installation of a novel object (a miniature video camera) inside their nest-boxes. We show that birds that score highly on a widely used exploration test (i.e., fast explorers) are more likely to accept and approach novel objects used in a seemingly unobtrusive sampling technique; thus, the sample collected overrepresents fast explorers. This form of behavior-related bias, sensitivity to novel objects, has largely been overlooked in sampling design. We demonstrate potential pitfalls of neglecting this behavior-related sampling bias in biological studies.

We measured daily energy expenditure (DEE) during the development periods of precocial chicks of five species of Arctic shorebirds spanning a broad range in size, in order to investigate the relationships between DEE, body size, and growth rate. We also quantified the effect of weather conditions on the energy expenditure of chicks to establish the impact of cold arctic weather on their time and energy budgets. We used the doubly labeled water method to measure DEE at ambient temperatures in an outside enclosure on the subarctic tundra at Churchill, Manitoba, Canada. Growth rate was highest in the smallest species, and in general decreased with adult size, as shown by the decrease in growth rate constant and later inflection point with increasing adult body mass. DEE ranged from 14 kJ day−1 in young chicks of the smaller species to 365 kJ day−1 in older chicks of the larger species. From hatching onward, DEE of shorebirds was high compared to DEE of chicks of altricial species, reflecting the high costs of locomotion and thermoregulation, and mass-specific DEE increased rapidly to adult levels. Chicks of smaller species metabolized more energy per unit mass and functioned at higher multiples of resting metabolic rate than chicks of larger species. As chicks of smaller species also had higher growth rates, and thus simultaneously invested in growth and mature function, it seems that shorebird chicks can adjust total metabolizable energy as well as its relative allocation between investment in growth and mature function. DEE was similar to cold-induced peak metabolic rates achieved by shivering thermogenesis. Because chicks were motionless during laboratory metabolism measurements, the relatively high level of DEE compared to these metabolic rates suggests that locomotion produces similar amounts of heat as shivering. Ambient temperature did not affect DEE in outdoor pens, although higher wind speed resulted in slightly increased energy expenditure. Heat produced by locomotion is possibly sufficient to sustain thermoregulation under local environments. Furthermore, when ambient temperatures are low, chicks spend more time brooding and less time foraging, which presumably counters the tendency to increase thermogenesis in response to cold.

Many local breeds are currently at risk because of replacement by a limited number of specialized commercial breeds. Concurrently, for many breeds, allelic diversity within breeds declines because of inbreeding. Gene banking of germplasm may serve to secure the breeds and the alleles for any future use, for instance to recover a lost breed, to address new breeding goals, to support breeding schemes in small populations to minimize inbreeding, and for conservation genetics and genomics research. Developments in cryobiology and reproductive technology have generated several possibilities for preserving germplasm in farm animals. Furthermore, in some mammalian and bird species, gene banking of material is difficult or impossible, requiring development of new alternative methods or improvement of existing methods. Depending on the species, there are interesting possibilities or research developments in the use of epididymal spermatozoa, oocytes and embryos, ovarian and testicular tissue, primordial germ cells, and somatic cells for the conservation of genetic diversity in farm- and other animal species. Rapid developments in genomics research also provide new opportunities to optimize conservation and sampling strategies and to characterize genome-wide genetic variation. With regard to gene banks for farm animals, collaboration between European countries is being developed through a number of organizations, aimed at sharing knowledge and expertise between national programmes. It would be useful to explore further collaboration between countries, within the framework of a European gene banking strategy that should minimize costs of conservation and maximize opportunities for exploitation and sustainable use of genetic diversity.

1. Climate change has caused a phenological mismatch between the timing of reproduction and the local food peak in many bird species. Late breeding birds therefore experience reduced food availability during chick rearing and are thus predicted to have an increased energy expenditure. Observational studies, however, show mixed results, perhaps because they compare energy expenditure across rather than within individuals at different levels of food availability. 2. In a cross foster experiment, we measured daily energy expenditure (DEE) twice within individuals during chick feeding (when chicks were 6 and 14 days old) for 28 free-living female great tits (Parus major). To avoid confounding effects of chick age, these females reared on both occasions a standardized foster brood of eight 10-day-old chicks during the 24-h measuring period. For all birds, food availability declined between the two measurements. 3. We show that DEE during chick feeding increased within females when food availability decreased. Variation in DEE within females is partly explained by brood visit rates, food availability and temperature. 4. DEE during chick feeding could be affected by the investment in previous stages of the reproductive attempt. However, energy expenditure during chick feeding was not correlated to energy expenditure during egg laying, measured in these same females. 5. Understanding of energetic costs during all phases of the reproductive cycle is important to forecast the consequences of climate warming on timing of reproduction.

In many animal species, embryos are exposed to maternal hormones that affect their development. Maternal hormone transfer varies with environmental conditions of the mother and is often interpreted as being shaped by natural selection to adjust the offspring to prevailing environmental conditions. Such hormone transfer requires genetic variability, which has not yet been experimentally demonstrated. Our study reports direct evidence for additive genetic variance of maternal androgens through a bidirectional selection on yolk testosterone (T) levels in Japanese quail. Lines selected for high egg T (HET) and low egg T (LET) concentration differed in yolk levels of this androgen, resulting in high realized heritability (h(2) = 0.42). Correlated responses to selection on other gonadal hormones indicated that selection specifically targeted biologically active androgens. Eggs of HET quail contained higher androstenedione and lower estradiol concentrations than did those of LET quail, with no line differences in yolk progesterone concentration. Plasma T concentrations in adult females were not affected by selection, seriously challenging the hypothesis that transfer of maternal hormones to offspring is constrained by hormone levels in a mother's circulation. Our results suggest that transfer of maternal T represents an indirect genetic effect that has important consequences for the evolution of traits in offspring.

Nowadays, contraceptives for birds are more en more used for the prevention of reproduction and for therapeutic reasons. In female animals, the indications for the use of contraceptives are abundant or chronic egglaying, eggbinding, dystocia, salpingitis, impaction of the salpinx, prolapse of the cloaca or salpinx, rupture of the salpinx, ovarian neoplasia or ovarian cysts. In male animals contraceptives are administered to obtain teaser males, to prevent reproduction, to treat testicular neoplasia and to improve the carcass quality of poultry. For several years researchers have been studying these diseases, their treatment and prevention. This review includes the hormonal therapies as well as the surgical and endoscopic contraceptive techniques. Furthermore, the reproductive anatomy and endocrinology of birds are described. In bird practices, the administration of chemical contraceptives as well as the performance of surgical techniques and endoscopies are on the increase. Since specialization is increasing rapidly in small animal practices, it can be expected that these procedures will become more frequent in the future. Anticonceptiemiddelen worden bij vogels steeds vaker gebruikt, zowel om voortplanting te voorkomen als voor therapeutische doeleinden. De indicaties om anticonceptie toe te passen bij vrouwelijke dieren zijn het overmatig leggen van eieren, legnood, dystocie, salpingitis, eileiderimpactie, cloaca- of eileiderprolaps, eileiderruptuur, ovariële neoplasieën en -cysten. Bij mannelijke dieren worden anticonceptiemiddelen toegepast om teasermannetjes te verkrijgen, de reproductie af te remmen, testistumoren te behandelen en de karkaskwaliteit van industriëel pluimvee te verbeteren. Reeds jarenlang worden deze aandoeningen evenals de behandeling en preventie ervan onderzocht. In dit overzichtsartikel worden de hormonale, chirurgische en laparoscopische anticonceptietechnieken beschreven die gebruikt worden bij vogels. Verder worden ook de anatomie van het voortplantingsstelsel en de endocrinologie ervan beschreven. Niettegenstaande chemische castratie bij vogels steeds vaker wordt toegepast, zijn ook de chirurgische en laparoscopische technieken aan een sterke opmars bezig. Gezien de stijgende specialisatie in de kleine huisdierenpraktijk wordt verwacht dat deze ingrepen in de toekomst steeds frequenter zullen worden uitgevoerd.

In laying hens, behavioral responses measured late in the laying period are associated with decreased performance. If measured early in the laying period, these behavioral responses could be used to predict performance later in life. The main objective of the present study was to investigate the association of the behavioral response toward a novel object at 23 wk of age with subsequent performance during the laying period. A total of 1,251 hens from 6 different pure-bred Rhode Island Red lines (208 hens per line on average) were housed in 318 cages (56 cages per line on average). Performance variables included egg production (both per hen-present and hen-housed); BW at 19, 51, and 69 wk of age; mortality; and feather damage at 63 wk. Hens from cages with an approach response realized greater total egg production (hen-day and hen-housed) and greater egg production in the middle (hen-housed) and end of the laying period (per hen present and hen housed) compared with hens from cages with a passive response toward the novel object. Approach responses were also associated with more feather damage, but not with BW or mortality. Low correlations were found between greater egg production and more feather damage. These results suggest that an approach response toward a novel object measured early in the laying period is associated with better performance later in the laying period. The novel object test early in the laying period can be used to predict subsequent performance, although possible causal mechanisms for this association remain to be investigated.

The increase or decrease in yolk androgens over the laying sequence of a clutch in birds may mitigate or enhance, respectively, the disadvantage of the last-hatched chicks, providing a potentially adaptive tool to adjust brood size to food conditions. This variation may involve a genetic component on which Darwinian selection can act. We found that two lines of a wild bird species selected for bold and shy personalities show, respectively, increased and decreased androgen concentrations over the laying sequence. The line showing the increase laid earlier in the season, when food conditions are normally sufficient to raise the whole brood. The line showing the decrease laid later, when food is normally scarce, which may facilitate brood reduction. The results indicate a correlated response in maternal hormone transfer to genetic selection on personality, which relates to ecological conditions.

Karyotypes of chicken (Gallus gallus domesticus; 2n = 78) and mallard duck (Anas platyrhynchos; 2n = 80) share the typical organization of avian karyotypes including a few macrochromosome pairs, numerous indistinguishable microchromosomes, and Z and W sex chromosomes. Previous banding studies revealed great similarities between chickens and ducks, but it was not possible to use comparative banding for the microchromosomes. In order to establish precise chromosome correspondences between these two species, particularly for microchromosomes, we hybridized 57 BAC clones previously assigned to the chicken genome to duck metaphase spreads. Although most of the clones showed similar localizations, we found a few intrachromosomal rearrangements of the macrochromosomes and an additional microchromosome pair in ducks. BAC clones specific for chicken microchromosomes were localized to separate duck microchromosomes and clones mapping to the same chicken microchromosome hybridized to the same duck microchromosome, demonstrating a high conservation of synteny. These results demonstrate that the evolution of karyotypes in avian species is the result of fusion and/or fission processes and not translocations.

National audience; Assessing the behavioural adaptation of an animal to its environment is complex, notably because numerous criteria can be taken into consideration. A better understanding of the relationships between criteria, particularly between behavioural and physiological responses, might help reduce the number of parameters required to assess animal welfare. The existence of relationships between behavioural and physiological responses of animals to potentially threatening situations has been suggested both by studies comparing animals reared in different environments and by those comparing animals with extreme genotypes. Moreover, the identification of coping styles in various species has strengthened the idea that physiological and behavioural responses could be related, although the precise laws governing such relationships are still difficult to establish and generalise. Thus, considering the complexity of these relationships, it appears reasonable to consider these two groups of responses as partially independent and as giving complementary information about animal welfare. In the future, the development of complex trait analyses as well as investigation at the level of the brain should improve understanding of the relationships between physiological and behavioural responses.; La multiplicité des critères susceptibles d’être utilisés pour évaluer l’adaptation comportementale d’un animal à son environnement a motivé l’étude des relations entre réponses physiologiques et comportementales, dans l’espoir que l’identification de telles relations puisse simplifier l’évaluation du bien-être animal. La comparaison d’animaux placés dans des environnements différents et la comparaison d’animaux aux génotypes extrêmes suggèrent l’existence de relations entre certaines réponses physiologiques et comportementales. La possibilité de catégoriser certains animaux selon leur stratégie de réponse adaptative, caractérisée par des associations répétables entre réponses comportementales et physiologiques, conforte cette hypothèse. Cependant, les relations ainsi suggérées semblent difficilement généralisables : il n’existe pas de relation univoque entre les réponses physiologiques et comportementales d’un animal face à une situation perçue comme menaçante. En l’état actuel des connaissances, la prise en compte de manière concomitante de critères physiologiques et comportementaux est essentielle pour apprécier le bien-être d’un animal. A l’avenir, des investigations en génomique fonctionnelle et en neurobiologie pourraient améliorer notre compréhension de ces relations.

1. A total of 1200 eggs were obtained from two pure line stocks of 'wild' and 'recessive white' quail of the Pharaoh strain (Coturnix coturnix Pharaoh), with two different breeder ages (17 or 34 weeks). The recessive white line was derived from mutant birds, which appeared spontaneously within the wild-type quail colony. 2. The analysis included plumage colour and breeder age as main effects together with their interaction. There were no significant effects for apparent fertility but hatchability of total and fertile eggs was affected by plumage colour variant and breeder age. 3. Body weight was affected by plumage colour throughout the growing period, whereas the differences attributable to breeder age were significant from 21 to 42 d only. 4. Main effects and their interaction were significant for feed conversion ratio until the end of the growing period, except at the age of 7 d for the effect of breeder age. 5. It was concluded that the hatchability and growth performance of the recessive white-type was not as good as the wild-type. The young breeders (17 weeks old) had the best hatchability and subsequent growth performance.

Newly hatched precocial chicks of arctic shorebirds are able to walk and regulate their body temperatures to a limited extent. Yet, they must also grow rapidly to achieve independence before the end of the short arctic growing season. A rapid growth rate may conflict with development of mature function, and because of the allometric scaling of thermal relationships, this trade-off might be resolved differently in large and small species. We assessed growth (mass) and functional maturity (catabolic enzyme activity) in leg and pectoral muscles of chicks aged 1-16 d and adults of two scolopacid shorebirds, the smaller dunlin (Calidris alpina: neonate mass 8 g, adult mass 50 g) and larger whimbrel (Numenius phaeopus; neonate mass 34 g, adult mass 380 g). Enzyme activity indicates maximum catabolic capacity, which is one aspect of the development of functional maturity of muscle. The growth rate-maturity hypothesis predicts that the development of catabolic capacity should be delayed in faster-growing muscle masses. Leg muscles of both species were a larger proportion of adult size at hatching and grew faster than pectoral muscles. Pectoral muscles grew more rapidly in the dunlin than in the whimbrel, whereas leg muscles grew more rapidly in the whimbrel. In both species and in both leg and pectoral muscles, enzyme activities generally increased with age, suggesting increasing functional maturity. Levels of citrate synthase activity were similar to those reported for other species, but L-3-hydroxyacyl-CoA-dehydrogenase and pyruvate kinase (PK) activities were comparatively high. Catabolic capacities of leg muscles were initially high compared to those of pectoral muscles, but with the exception of glycolytic (PK) capacities, these subsequently increased only modestly or even decreased as chicks grew. The earlier functional maturity of the more rapidly growing leg muscles, as well as the generally higher functional maturity in muscles of the more rapidly growing dunlin chicks, contradicts the growth rate-maturity function trade-off and suggests that birds have considerable latitude to modify this relationship. Whimbrel chicks, apparently, can rely on allometric scaling of power requirements for locomotion and the thermal inertia of their larger mass to reduce demands on their muscles, whereas dunlin chicks require muscles with higher metabolic capacity from an earlier age. Thus, larger and smaller species may adopt different strategies of growth and tissue maturation.

The main aims of this paper are: a) to propose the use of porphyrins in excreta (nondestructive biomarker) as an alternative to the traditional liver porphyrins (destructive biomarker) in the hazard assessment of birds contaminated with PCBs and; b) to propose the use of a fast and inexpensive fluorimetric assay, proposed by Grandchamp et al. [1], as an alternative to HPLC for rapid evaluation of porphyrins in biological samples. The proposals were tested in the laboratory using three groups of Japanese quail (Coturnix coturnix japonica), with commercial bird food containing different concentrations of Arochlor 1260 for 25 days, and an untreated control group of the same birds.