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PubMed2004

Monitoring for lead pollution using feathers of feral pigeons (Columba livia) from Korea.

We investigated lead exposure conditions using unwashed feathers of feral pigeons as a monitor for lead pollution from rural, central urban, and four industrial complex areas in Korea with different ambient lead concentrations. Overall, the lead levels in the feathers increased when the atmospheric lead levels increased, so that the lead levels in the feathers from urban and industrial areas were two to four times greater than those in the rural area. However, there are no significant differences in the liver lead concentrations between rural and the other areas, suggesting that the lead originated from ingestion are not differences in locations. A positive correlation was found between the concentration of lead in livers and feathers from rural, indicating that the feather lead concentrations in this area seem to mainly reflect the internal tissue lead through the metabolic process. However, there are no significant correlations in the other areas, and we observed a relatively higher lead accumulation ratio of feathers to livers. It, therefore, indicates that external contamination onto the feather surface may be an important source for lead levels in feathers rather than transfer from internal tissue lead.

Animals↗
PubMed2005

Mapping stem cell activities in the feather follicle.

It is important to know how different organs 'manage' their stem cells. Both hair and feather follicles show robust regenerative powers that episodically renew the epithelial organ. However, the evolution of feathers (from reptiles to birds) and hairs (from reptiles to mammals) are independent events and their follicular structures result from convergent evolution. Because feathers do not have the anatomical equivalent of a hair follicle bulge, we are interested in determining where their stem cells are localized. By applying long-term label retention, transplantation and DiI tracing to map stem cell activities, here we show that feather follicles contain slow-cycling long-term label-retaining cells (LRCs), transient amplifying cells and differentiating keratinocytes. Each population, located in anatomically distinct regions, undergoes dynamic homeostasis during the feather cycle. In the growing follicle, LRCs are enriched in a 'collar bulge' niche. In the moulting follicle, LRCs shift to populate a papillar ectoderm niche near the dermal papilla. On transplantation, LRCs show multipotentiality. In a three-dimensional view, LRCs are configured as a ring that is horizontally placed in radially symmetric feathers but tilted in bilaterally symmetric feathers. The changing topology of stem cell activities may contribute to the construction of complex feather forms.

Animals↗
PubMed2000

Feather keratin hydrolysis by a Vibrio sp. strain kr2.

The aim of the study was to characterize feather-degrading bacteria isolated from poultry industry waste. A Vibrio sp. strain kr2 producing a high keratinolytic activity when cultured on native feather-containing broth was isolated. The bacterium grew with an optimum at pH 6.0 and 30 degrees C, where maximum featherdegrading activity was also observed. Keratinase production was similar at both 25 and 30 degrees C, while the maximum concentration of soluble protein was reached at 30 degrees C. Reduction of disulphide bridges was also observed, increasing with cultivation time. The keratinase of strain kr2 was active on azokeratin, azocasein, benzoyl-arginine-p-nitroanilide and Ala-Ala-p-nitroanilide as substrates. The amino acid composition of the feather hydrolysate was determined, presenting similarities with that reported for feather lysate, feather meal and raw feathers. A novel feather-degrading bacterium was isolated and characterized, showing high keratinolytic activity. Complete feather degradation was achieved during cultivation. Strain kr2 shows potential for use for biotechnological processes involving keratin hydrolysis.

Amino Acids↗
PubMed2000

Effect of foraging material and food form on feather pecking in laying hens.

1. The aim was to test whether provision of foraging material and food form influence feather pecking and feather damage in laying hens. 2. From week 19 of age, 16 groups of 11 hens (white Lohman Selected Leghorn hybrids) were kept in pens with or without access to long-cut straw as foraging material and fed on either mash or pellets. 3. Foraging behaviour was increased in hens with access to straw and time spent feeding was increased in hens fed on mash. In addition, hens fed on mash had longer feeding bouts and higher rates of pecking at the food during feeding than hens fed on pellets. 4. There were interaction effects of foraging material and food form on both feather pecking and feather damage. High rates of feather pecking and pronounced feather damage were only found in hens housed without access to straw and fed on pellets. In groups characterised by high rates of feather pecking the hens also showed more severe forms of this behaviour. 5. Differences in the time budgets of hens kept in different housing conditions suggested that birds fed on mash used the food not only for feeding but also as a substrate for foraging behaviour. 6. In order to avoid problems with feather pecking it is recommended that laying hens are provided with foraging material and fed on mash.

Animal Feed↗
PubMed2001

Influence of hydration on the mechanical performance of duck down feathers.

1. We report the first measurements to be made on the effects of hydration on the mechanical properties of commercially-prepared duck down feathers. Tensile tests were performed, to failure, on isolated barbs of down feathers at 50% RH and with fully-hydrated (wet) feathers. 2. The Young's modulus (stiffness) and ultimate stress (strength) of the feathers was higher at 50% RH than when wet. Wet feathers, however, failed at greater extension than dry feathers. The implications for down feather performance and for the use of feathers as a structural material are discussed.

Animals↗
PubMed1992

Metal levels in regrown feathers: assessment of contamination on the wintering and breeding grounds in the same individuals.

Birds are useful indicators of environmental contamination because they are relatively large, conspicuous, top predators in food chains. However, concentrations of contaminants in a bird's tissues reflect the bird's exposure over wide temporal and spatial scales. Birds are most useful as monitors of exposure when these scales are known. In this paper we report concentrations of lead, cadmium, mercury, and selenium in breast feathers of common terns (Sterna hirundo) and roseate terns (S. dougallii) trapped during incubation at breeding colonies in New York and Massachusetts. Terns arrived on the breeding grounds with breast feathers grown on their wintering grounds, and regrew certain feathers that were plucked for analysis. The regrown feathers were themselves plucked, and both sets of feathers were analyzed. For roseate terns at Cedar Beach and common terns at both sites there was a significant increase in mercury levels in the feathers grown on the breeding grounds compared to those grown on the wintering ground. The differences in mercury were far greater at Bird Island than at Cedar Beach. Selenium levels at Cedar Beach were higher for the regrown feathers than the initial feathers for roseate terns, but not for common terns. Lead and cadmium levels were not significantly different at either site for either species. These results suggest that terns are exposed to significantly higher levels of mercury in the northeastern United States than they are in the wintering grounds in South America.

Animals↗
PubMed1985

Expression of cell-adhesion molecules in embryonic induction. I. Morphogenesis of nestling feathers.

The potential relationship of cell adhesion to embryonic induction during feather formation was examined by immunohistochemical analysis of the spatiotemporal distribution of three cell-adhesion molecules (CAMs), neural CAM (N-CAM), liver CAM (L-CAM), and neuron-glia CAM (Ng-CAM), and of substrate molecules (laminin and fibronectin) in embryonic chicken skin. The N-CAM found at sites of embryonic induction in the feather was found to be similar to brain N-CAM as judged by immuno-cross-reactivity, migratory position in PAGE, and the presence of embryonic to adult conversion. In contrast to the N-CAM found in the brain, however, only one polypeptide of Mr 140,000 was seen. N-CAM-positive dermal condensations were distributed periodically under L-CAM-positive feather placodes at those sites where basement membranes are known to be disrupted. After initiation of induction, L-CAM-positive placode cells became transiently N-CAM-positive. N-CAM was asymmetrically concentrated in the dorsal region of the feather bud, while fibronectin was concentrated in the ventral region. During feather follicle formation, N-CAM was expressed in the dermal papilla and was closely apposed to the L-CAM-positive papillar ectoderm, while the dermal papilla showed no evidence of laminin or fibronectin. The collar epithelium was both N-CAM- and L-CAM-positive. During the formation of the feather filament, N-CAM appeared periodically and asymmetrically on basilar cells located in the valleys between adjacent barb ridges. In contrast to the two primary CAMs, Ng-CAM was found only on nerves supplying the feather and the skin. These studies indicate that at each site of induction during feather morphogenesis, a general pattern is repeated in which an epithelial structure linked by L-CAM is confronted with periodically propagating condensations of cells linked by N-CAM.

Animals↗
PubMed2003

Heritability of feather pecking and open-field response of laying hens at two different ages.

The objective of the current study was to estimate heritabilities (h2) of feather pecking and open-field response of laying hens at two different ages. An F2 cross, originating from a high and a low feather pecking line of laying hens, was used for the experiment. Each of the 630 birds of the F2 cross was subjected to an open-field test (individual, 10 min) at 5 and 29 wk of age and to a social feather pecking test (groups of five birds on wood shavings, 30 min) at 6 and 30 wk of age. Both tests were performed in a square open field (1.25 x 1.25 m). Behavior was recorded directly from a monitor. Heritabilities of feather pecking and open-field behaviors were calculated. In the open-field test at 5 wk of age, high h2 were found for most traits, ranging from 0.20 for the frequency of flying to 0.49 for number of steps. In the social test at 6 wk, gentle feather pecking (0.12) and ground pecking (0.13) were found to be heritable. When both tests were repeated at 29 and 30 wk of age, h2 estimates were lower for the open-field test, ranging from 0.10 for duration of sitting to 0.20 for latency to first step. In the social test, however, higher h2 estimates of 0.15 for gentle feather pecking and 0.30 for ground pecking were found compared with 6 wk of age. In conclusion, gentle feather pecking and open-field behaviors may be used in selection against feather pecking.

Age Factors↗
PubMed2005

Feathers at nests are potential female signals in the spotless starling.

Although the presence of feathers in the nest is widespread among birds, it has not been previously suggested that feathers can be used as sexual signals. Females of the spotless starling (Sturnus unicolor) regularly carry feathers to their nest, mostly during laying and incubation. We show that the arrangement of these feathers was non-random with respect to the side (obverse or reverse) placed upwards (which can be viewed from the nest entrance). Feathers of the wood pigeon (Columba palumbus) and the spotless starling, which exhibit higher ultraviolet and visible reflectance on their reverse side, were predominantly placed with this side upwards. On the contrary, feathers of the jay (Garrulus glandarius) were predominantly found exhibiting the obverse side, which possesses higher reflectance in this species. Feathers of the azure-winged magpie (Cyanopica cyana), with similar reflectance values on either side, were placed indiscriminately in obverse and reverse positions. The results suggest that feathers are arranged to maximize their conspicuousness within the nest and hence that they might be potentially used as intraspecific signals.

Animals↗
PubMed2000

Cross-sectional study of the prevalence of feather pecking in laying hens in alternative systems and its associations with management and disease.

A cross-sectional study of risk factors for feather pecking in layings hens in alternative systems was carried out in July 1998. A total of 637 questionnaires were sent out to farmers and producer groups and, after two reminders, the final response rate was 51.5 per cent. The outcome variable was feather pecking after point of lay. Over 55 per cent of the farmers reported that feather pecking had occurred in the last depopulated flock. This outcome was compared with the management procedures reported by flock managers by using univariate statistics. Factors associated with feather pecking with a significance < or = 0.05 were then tested in two logistic regression models. In the first model the following factors were associated with an increased risk of feather pecking: less than 50 per cent of the flock using the outdoor area on a fine and sunny day, the occurrence of egg peritonitis and the occurrence of infectious bronchitis. The direction of the association between feather pecking and these infectious diseases was unclear, so in the second model only factors which were consistent throughout the laying period were tested. The following factors were associated with an increased risk of feather pecking: less than 50 per cent of the flock using the outdoor area on a fine and sunny day; three or more changes of diet during lay; the inspection of the flock by one person; an absence of loose litter at the end of lay; a temperature in the hen house of less than 20 degrees C; turning the lights up when the flock was inspected; and the use of bell-drinkers. It is concluded that some of these factors could inhibit foraging and dust-bathing behaviour and others may increase competition or frustration, both of these changes having been shown experimentally to initiate feather pecking behaviour.

Animal Husbandry↗
PubMed1999

Wnt-7a in feather morphogenesis: involvement of anterior-posterior asymmetry and proximal-distal elongation demonstrated with an in vitro reconstitution model.

How do vertebrate epithelial appendages form from the flat epithelia? Following the formation of feather placodes, the previously radially symmetrical primordia become anterior-posterior (A-P) asymmetrical and develop a proximo-distal (P-D) axis. Analysis of the molecular heterogeneity revealed a surprising parallel of molecular profiles in the A-P feather buds and the ventral-dorsal (V-D) Drosophila appendage imaginal discs. The functional significance was tested with an in vitro feather reconstitution model. Wnt-7a expression initiated all over the feather tract epithelium, intensifying as it became restricted first to the primordia domain, then to an accentuated ring pattern within the primordia border, and finally to the posterior bud. In contrast, sonic hedgehog expression was induced later as a dot within the primordia. RCAS was used to overexpress Wnt-7a in reconstituted feather explants derived from stage 29 dorsal skin to further test its function in feather formation. Control skin formed normal elongated, slender buds with A-P orientation, but Wnt-7a overexpression led to plateau-like skin appendages lacking an A-P axis. Feathers in the Wnt-7a overexpressing skin also had inhibited elongation of the P-D axes. This was not due to a lack of cell proliferation, which actually was increased although randomly distributed. While morphogenesis was perturbed, differentiation proceeded as indicated by the formation of barb ridges. Wnt-7a buds have reduced expression of anterior (Tenascin) bud markers. Middle (Notch-1) and posterior bud markers including Delta-1 and Serrate-1 were diffusely expressed. The results showed that ectopic Wnt-7a expression enhanced properties characteristic of the middle and posterior feather buds and suggest that P-D elongation of vertebrate skin appendages requires balanced interactions between the anterior and posterior buds.

Animals↗
PubMed2001

Are hippoboscid flies a major mode of transmission of feather mites?

Feather mites (Astigmata) are distributed around the world, living on the feathers of birds, but their mechanisms for transmission among hosts are not fully understood. There is anecdotal evidence of feather mites attached to louseflies (Diptera: Hippoboscidae), suggesting that feather mites may use these flies as a mode of phoretic transmission among birds. Two bird-lousefly associations (alpine swift Apus melba-Crataerina melbae and feral pigeon Columba livia-Pseudolynchia canariensis) were inspected to test the hypothesis that feather mites use hippoboscid flies as major mode of transmission. Both bird species showed a high prevalence and abundance of feather mites and louseflies. However, no feather mites were found attached to the 405 louseflies inspected, although skin mites (Epidermoptidae and Cheyletiellidae) were found on louseflies collected from feral pigeons. This study suggests that feather mites do not use hippoboscid flies as a major mode of transmission among birds.

Animals↗
PubMed1977

A feather abnormality in chicks fed diets deficient in certain amino acids.

A feather abnormality was observed in chicks during bio-assay investigations with eleven essential amino acids. As dietary valine, leucine, isoleucine, glycine or phenylalanine and tyrosine levels decreased, a similar progressive feather abnormality became apparent. The outstanding feature of the feather abnormality was the concave structure of the feathers as they bent upward from the body. This structure gave the feathers a ragged appearance. The feather abnormality is described and illustrated. The percentage of dietary amino acids used were: valine, 0.40, 0.50, 0.60, and 0.70; leucine, 0.60, 0.68, 0.76, and 0.82; isoleucine, 0.32, 0.38, 0.44, and 0.50; glycine, 0.30, 0.35, 0.40, and 0.45; or phenylalanine and tyrosine, 0.65, 0.70, 0.75, and 0.80. Chicks fed the highest level of valine (0.50%), histidine (0.15%) or methionine to cystine ratio of 1:1 (0.30%) had normal feathers. In contrast, chicks fed the highest levels of either leucine, isoleucine, glycine or phenylalanine and tyrosine had abnormal feathers.

Amino Acids, Essential↗
PubMed2003

Feather duvet lung.

BACKGROUND: Bird fancier's lung (BFL) is a type of hypersensitivity pneumonitis, which is induced by inhalation of bird related antigens. The diagnosis of BFL induced by feathers is difficult because feathers are generally not recognized as a causative antigen of BFL. We report a female case of chronic BFL presumably due to a feather duvet, which presents as pulmonary fibrosis. CASE REPORT: A 73 year-old woman presented with exertional dyspnea for the last three years. She had raised two pigeons for three years (1971-1973) in her forties and had been using a feather duvet for the last eight years (1992-2000). A chest X-ray showed reticular infiltrates in the both peripheral lung field and an HRCT scan showed scattered consolidation, micronodules, and peribronchial ground-glass opacities. Lymphocyte proliferation to the feather antigen was positive and inhalation provocation test using a bird antigen was also positive. Thoracoscopic biopsy specimens showed organization, cholesterol clefts, alveolitis around terminal and respiratory bronchioles--all of which are consistent with chronic hypersensitivity pneumonitis. Clinical findings have spontaneously improved after she stopped using her feather duvet. CONCLUSIONS: Feather beds including duvets, pillows, and cushions are now popular all over the world. Physicians should be aware of feathers as a cause of BFL since this induction seems to be more prevalent.

Aged↗
PubMed1992

Hydrocortisone perturbs the cell proliferation pattern during feather morphogenesis: evidence for disturbance of cephalocaudal orientation.

In this study, we have monitored the spatial distribution of S-phase cells during successive stages of normal feather morphogenesis using the specific marker BrdU. We also disturbed the development program by administration of hydrocortisone on the chorioallantoic membrane of 6.5-day chick embryos and examined the resulting pattern of BrdU incorporation. Our results show that a specific spatio-temporal pattern of cell proliferation occurs during successive stages of feather development and that this pattern accounts for the growth of feather buds according to the cephalocaudal orientation. Our experimental analysis showed that the stage-dependent alteration of feather morphogenesis (as shown by Züst, Ann. Embryol. Morphogen. 4, 1971 and confirmed by Démarchez et al., Dev. Biol. 106, 1984), is based on a stage-dependent alteration of the proliferation pattern in the epidermis. Forty-eight hours after treatment, non-induced epidermis ceases DNA synthesis and is unable to form placodes. Induced epidermis at the placodal and dermal condensation stages fails to produce the cohorts of S-phase cells responsible for the caudal outgrowth and the slanting shape of the buds. These young buds display anarchic proliferation in the whole epidermis possibly resulting in the appearance of "curly" feathers. Together, these results show the importance of the spatial pattern of ectodermal and mesodermal cell proliferation during the normal feather morphogenesis. Moreover, they corroborate the particular role of epidermis both in the establishment of feather rudiments and in the cephalocaudal orientation of the feathers.

Animals↗
PubMed1978

Feather-forming capacities of the avian extra-embryonic somatopleure.

Blocks of 12.5- or 13.5-day embryonic mouse upper-lip dermis were introduced under the ectoderm of the extra-embryonic area of 2- to 3-day chick or duck embryos. Two kinds of ectopic cutaneous appendages were produced: either arrested feathers alone, or arrested feathers and full-grown feathers. The former developed in the ectoderm overlying the implanted mouse dermal cells, the latter formed in their close vicinity, but contained host dermal cells exclusively. Thus, avian extra-embryonic somatopleure, both ectoderm and mesoderm, possesses the information for feather development: the extra-embryonic ectoderm, if it is brought in contace with an appendage-forming dermis, is able to respond to the dermal induction by initiating feather morphogenesis; the extra-embryonic mesoderm, if it is experimentally transformed into a dense dermis, can express its feather-forming capacity by specifying feather tract morphology and barb-ridge number, thus leading to the acievement of feather morphogenesis.

Animals↗
PubMed1993

Immunocytochemical demonstration of progesterone and estrogen receptors in feathers and skin of adult hens.

Clinical evidence indicates that ovarian steroids are involved in the control of moulting in the chicken. This immunocytochemical study investigates if feather papillae and growing feathers are target tissues for ovarian steroids. Progesterone (PR) and estrogen (ER) receptors were demonstrated using monoclonal antibodies in feathers and surrounding skin of laying hens. Both receptor types were present in the nuclei of dermal papillae and in the nuclei of the epidermal germinative layer cells of growing and full-grown feathers. In growing feathers most nuclei of the intermediate layer (ramogenic column, rachis, axial plate) were immunostained, but during the final stages of differentiation into barbules, only estrogen receptors remained prominent. Skin adjacent to feathers showed ER and PR receptors in nuclei of cells from epidermis, muscles and arteries. During egg-laying pause, plasma progesterone levels decrease ten-fold and it is supposed that this results in a much greater endocrine efficiency of the remaining estrogen levels which are only reduced by 50% when egg-laying stops. The moult-inhibiting effect of progesterone in laying hens could be due to its well-established downregulation on estrogen receptors and therefore, on the endocrine effect of ER at cellular level in feather papillae. Such may account for the presence of both receptor types on the same feather cells, as observed in the present study.

Animals↗
PubMed1993

Mercury levels in eggs, tissues, and feathers of herring gulls Larus argentatus from the German Wadden Sea Coast.

The relationships between mercury levels in eggs, tissues, and feathers of male and female herring gulls caught at their nests at a colony on the German Wadden Sea Coast were investigated, and an assessment of mercury intake and excretion of these birds was made. Samples of the liver, ovary, pectoral muscle, and body feathers, as well as the primary feather (in some cases), and eggs were taken from 37 adult herring gulls. Analysis of total mercury in all samples showed that body-feather and tissue levels were independent of sex. There was, however, a significant difference between levels of mercury in the primary feathers of male and female birds. Egg levels were not correlated to pectoral muscle, ovary, or feather levels although they were positively correlated with mercury levels in the liver. Liver levels were in turn correlated with mercury levels in the ovary. The ratio of mean feather to mean egg concentration ranged from 3.7 to 5.5 according to which feather was used. It was estimated that herring gulls from the Wadden coast ingested between 825 and 1337 microg of mercury in the year prior to analysis. It was also estimated that female birds may excrete over 20% more mercury via their eggs than could be excreted by male birds.

Journal Article↗