Interactions between avian viruses and skin in farm birds.

This article reviews the avian viruses that infect the skin of domestic farm birds of primary economic importance: chicken, duck, turkey, and goose. Many avian viruses (e.g., poxviruses, herpesviruses, Influenza viruses, retroviruses) leading to pathologies infect the skin and the appendages of these birds. Some of these viruses (e.g., Marek's disease virus, avian influenza viruses) have had and/or still have a devasting impact on the poultry economy. The skin tropism of these viruses is key to the pathology and virus life cycle, in particular for virus entry, shedding, and/or transmission. In addition, for some emergent arboviruses, such as flaviviruses, the skin is often the entry gate of the virus after mosquito bites, whether or not the host develops symptoms (e.g., West Nile virus). Various avian skin models, from primary cells to three-dimensional models, are currently available to better understand virus-skin interactions (such as replication, pathogenesis, cell response, and co-infection). These models may be key to finding solutions to prevent or halt viral infection in poultry.

Assessing the trophic ecology and migration on the exposure of cape petrels and Wilson's storm petrels from Antarctica to perfluoroalkylated substances, trace and major elements.

Chemical pollution is a global concern as contaminants are transported and reach even the remote regions of Antarctica. Seabirds serve as important sentinels of pollution due to their high trophic position and wide distribution. This study examines the influence of migration and trophic ecology on the exposure of two Antarctic seabirds, Wilson's storm petrel (Oceanites oceanicus - Ooc), and Cape petrel (Daption capense - Dca), to chemical elements and perfluoroalkyl substances (PFAS). Our methodology involved assessing the concentration of these pollutants in feather samples obtained from carcasses, offering a practical means for monitoring contamination. Trace and major element concentrations were comparable in both species, suggesting that migratory patterns have a minimal impact on exposure levels. However, Ooc had higher concentration of PFAS compared to Dca (mean, ng g-1dry weight, PFOA: Ooc:0.710, Dca:0.170; PFTrDA: Ooc:0.550, Dca:0.360, and PFTeDA: Ooc:1.01, Dca:0.190), indicating that migration to the more polluted Northern Hemisphere significantly affects PFAS exposure. Furthermore, while no strong associations were found between either trace elements or PFAS and the three stable isotopes (δ13C, δ15N, and δ34S), a negative association was observed between PFUnDA and δ15N, hinting at potential biodilution. The research concludes that the migratory patterns of these seabird species affect their PFAS exposure, underscoring the critical need for further exploration and understanding of these relationships to better inform conservation strategies.

Black Vulture (Coragyps atratus) feathers as bioindicators of exposure to metals and metalloids contamination in urban, semi-urban, and rural areas from Campeche state, Mexico.

Landfills are sources of soil, water, and air pollution due to the release of toxic compounds such as metals and metalloids. In both tropical and temperate environments, scavenger birds such as the Black Vulture (Coragyps atratus) that have learned to use these sites as a feeding area are probably exposed to metals, metalloids and other "persistent bioaccumulative toxic substances (PBTs)" released in open dumpsite (OD) and sanitary landfill (SL). The objective of this study is to evaluate the presence and distribution of toxic metals (Al, Sn, Hg, Cu, Pb, Cd, Cr) and As in OD and SL from urban, semi-urban and rural localities in Campeche, México, using molting feathers of C. atratus as bioindicators. A total of 125 Black Vulture primary and secondary wing feathers were collected from OD and SL. Metals were determined by voltammetry through acid digestion. The highest levels of metals occurred in landfills in urban, semi-urban, and rural localities. The elements with the highest concentrations were Al, with an average of 35.67 ± 33.51 µg g-1 from rural environments, and As, with 16.20 ± 30.06 µg g-1 from the urban localities. Mercury was the only element that had a very homogeneous distribution between the three environments we studied. In general, Pb, Hg, Cu and Cd were the elements that presented the lowest concentrations with 0.32 ± 0.35, 0.16 ± 0.22, 0.14 ± 0.31 and 0.06 ± 0.10 µg g-1, respectively regardless of any particular location or environment. Black Vultures from dumpsites are good bioindicators of what humans consume in urban, semi-urban, and rural environments. However, the conservation of vultures is of great importance since these scavenger birds perform ecosystem services by feeding on decomposing organic material.

Ecotoxicological Consequences of Urbanization: A Multi-Biomarker Approach to Assessing Sewage Treatment Plant Effects on Free-Living Birds.

Birds are good bioindicators of disturbance in the environment. They are present in different habitats and trophic levels. In addition, rapid urbanization has led birds to use cities as shelter and for seeking food resources. Sewage treatment plants (STPs) are suitable locations for free-living birds within cities. However, few studies address the impacts of emerging pollutants from sewage treatment plants on wild birds. In this sense, the aim of this study was to analyze the genotoxic, mutagenic, and immunological impacts from metal and pollutant exposure on free-living birds collected at a STP. For comparison, birds were collected in a preserved environment, the Silvania National Forest (FLONA). To achieve this, we used non-destructive biomarkers sensitive to environmental changes. Birds were collected in both environments using mist nets. After collection, birds were weighed, measured, species-identified, and released. Blood was collected for comet assay, micronucleus test, and leukocyte profile, while feathers were collected for metal concentration analysis. Water physicochemical parameters were measured at both sites, and water samples were collected for metal analysis. Our results demonstrated that birds collected at the STP exhibit a higher frequency of genotoxic damage and erythrocyte abnormalities, and increased immune response compared to FLONA birds. Traces of potentially toxic metals, such as Hg and As, were found in the birds feathers from both environments, raising concerns about metal contamination in both environments. Trophic guilds appear to respond similarly to exposure. The parameters and metals found in the water reflect environmental characteristics and may be influencing pollutant availability. Finally, despite the advancement of our findings, studies linking these damages to detrimental effects on behavior and reproduction are encouraged.

Pre-Columbian transregional captive rearing of Amazonian parrots in the Atacama Desert.

The feathers of tropical birds were one of the most significant symbols of economic, social, and sacred status in the pre-Columbian Americas. In the Andes, finely produced clothing and textiles containing multicolored feathers of tropical parrots materialized power, prestige, and distinction and were particularly prized by political and religious elites. Here we report 27 complete or partial remains of macaws and amazon parrots from five archaeological sites in the Atacama Desert of northern Chile to improve our understanding of their taxonomic identity, chronology, cultural context, and mechanisms of acquisition. We conducted a multiproxy archaeometric study that included zooarchaeological analysis, isotopic dietary reconstruction, accelerated mass spectrometry radiocarbon dating, and paleogenomic analysis. The results reveal that during the Late Intermediate Period (1100 to 1450 CE), Atacama oasis communities acquired scarlet macaws (Ara macao) and at least five additional translocated parrot species through vast exchange networks that extended more than 500 km toward the eastern Amazonian tropics. Carbon and nitrogen stable isotopes indicate that Atacama aviculturalists sustained these birds on diets rich in marine bird guano-fertilized maize-based foods. The captive rearing of these colorful, exotic, and charismatic birds served to unambiguously signal relational wealth in a context of emergent intercommunity competition.

Nutritional and technological potential of chicken feathers for the food industry.

1. The production of chicken meat has resulted in high volumes of byproducts, such as feathers, bones, skin, viscera, and feet. The structure of feathers is one of the most complex among vertebrates, with a central axis and lateral filamentary structures, providing rigidity, lightness, and flexibility. Chicken feathers are composed of proteins, lipids, and water, with the highest protein content, especially keratin, which is responsible for the material's rigidity.2. Industries still make little use of feathers, which are generally intended for the production of flour or organic fertilisers. These are low added value products, and discarded feathers can harm the environment.3. Keratin extraction techniques and resulting protein hydrolysates have been studied in chicken feathers. Acid, alkaline or enzymatic hydrolysis is the most commonly used method for obtaining molecules with functional properties such as antioxidant, antimicrobial, antihypertensive and antidiabetic activity.4. The development of keratin-based biodegradable films represents an area of interest for reducing the economic and environmental impacts caused by inappropriate disposal of feathers.

Microbiota composition and diversity of multiple body sites vary according to reproductive performance in a seabird.

The microbiota is suggested to be a fundamental contributor to host reproduction and survival, but associations between microbiota and fitness are rare, especially for wild animals. Here, we tested the association between microbiota and two proxies of breeding performance in multiple body sites of the black-legged kittiwake, a seabird species. First we found that, in females, nonbreeders (i.e., birds that did not lay eggs) hosted different microbiota composition to that of breeders in neck and flank feathers, in the choanae, in the outer-bill and in the cloacae, but not in preen feathers and tracheae. These differences in microbiota might reflect variations in age or individual quality between breeders and nonbreeders. Second, we found that better female breeders (i.e., with higher body condition, earlier laying date, heavier eggs, larger clutch, and higher hatching success) had lower abundance of several Corynebacteriaceae in cloaca than poorer female breeders, suggesting that these bacteria might be pathogenic. Third, in females, better breeders had different microbiota composition and lower microbiota diversity in feathers, especially in preen feathers. They had also reduced dispersion in microbiota composition across body sites. These results might suggest that good breeding females are able to control their feather microbiota-potentially through preen secretions-more tightly than poor breeding females. We did not find strong evidence for an association between reproductive outcome and microbiota in males. Our results are consistent with the hypothesis that natural variation in the microbiota is associated with differences in host fitness in wild animals, but the causal relationships remain to be investigated.

Description of natal down of the ostrich (Struthio camelus) and comparison with common quail (Coturnix coturnix): Developmental and evolutionary implications.

Natal down is a feather stage that differs in both form and function from the definitive feathers of adult birds. It has a simpler structure that has been speculated to be similar to the body coverings of non-avian dinosaurs. However, inference of the evolution of natal down has been limited by our understanding of its structural variation in extant birds. Most descriptive work has focused on neognathous birds, limiting our knowledge of the full diversity of feathers in extant taxa. Here, we describe the natal down of a post-hatch ostrich (Struthio camelus) and compare it to that of a post-hatch quail (Coturnix coturnix). We confirm the presence of featherless spaces (apteria) in S. camelus and the lack of barbules on the tips of natal down in both species. We also find differences between dorsal and ventral natal down structures, such as barbule density in S. camelus and the extent of the bare portion of the barb in both species. Surprisingly, we do not find that the neoptiles of either species follow the ideal morphologies for increasing insulation. Finally, we hypothesize that the different barb types present in S. camelus natal down result from a large addition of new barb ridges during development, which is not known except in feathers with a rachis. These results have implications for our understanding of how structure informs function and development in understudied feather types, such as those shared by non-avian dinosaurs.

Circumpolar assessment of mercury contamination: the Adélie penguin as a bioindicator of Antarctic marine ecosystems.

Due to its persistence and potential ecological and health impacts, mercury (Hg) is a global pollutant of major concern that may reach high concentrations even in remote polar oceans. In contrast to the Arctic Ocean, studies documenting Hg contamination in the Southern Ocean are spatially restricted and large-scale monitoring is needed. Here, we present the first circumpolar assessment of Hg contamination in Antarctic marine ecosystems. Specifically, the Adélie penguin (Pygoscelis adeliae) was used as a bioindicator species, to examine regional variation across 24 colonies distributed across the entire Antarctic continent. Mercury was measured on body feathers collected from both adults (n = 485) and chicks (n = 48) between 2005 and 2021. Because penguins' diet represents the dominant source of Hg, feather δ13C and δ15N values were measured as proxies of feeding habitat and trophic position. As expected, chicks had lower Hg concentrations (mean ± SD: 0.22 ± 0.08 µg·g‒1) than adults (0.49 ± 0.23 µg·g‒1), likely because of their shorter bioaccumulation period. In adults, spatial variation in feather Hg concentrations was driven by both trophic ecology and colony location. The highest Hg concentrations were observed in the Ross Sea, possibly because of a higher consumption of fish in the diet compared to other sites (krill-dominated diet). Such large-scale assessments are critical to assess the effectiveness of the Minamata Convention on Mercury. Owing to their circumpolar distribution and their ecological role in Antarctic marine ecosystems, Adélie penguins could be valuable bioindicators for tracking spatial and temporal trends of Hg across Antarctic waters in the future.

Multiresidue Determination of 26 Quinolones in Poultry Feathers Using UPLC-MS/MS and Their Application in Residue Monitoring.

As a non-traditional sample matrix, feather samples can be used to effectively monitor antibiotic addition and organismal residue levels in poultry feeding. Therefore, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously determine the residue levels of 26 quinolones in poultry feathers. The feather samples were extracted by sonication with a 1% formic acid and acetonitrile mixture in a water bath at 50 °C for 30 min, purified by the adsorption of multiple matrix impurities, dried with nitrogen, redissolved, and analyzed by UPLC-MS/MS. The linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision were calculated. The 26 antibiotics demonstrated good linearity in the linear range. The recoveries and coefficients of variation were 78.9-110% and <13.7% at standard spiked levels of 10, 100 and 200 µg/kg, respectively. The LOD and LOQ were 0.12-1.31 and 0.96-2.60 µg/kg, respectively. The method also successfully identified quinolone residues in 50 poultry feather samples. The results showed that quinolones can accumulate and stabilize for a certain period of time after transferring from the body to the feathers of poultry.

Feather chemicals contain information about the major histocompatibility complex in a highly scented seabird.

Mate choice informed by the immune genes of the major histocompatibility complex (MHC) may provide fitness benefits including offspring with increased immunocompetence. Olfactory cues are considered the primary mechanism organisms use to evaluate the MHC of potential mates, yet this idea has received limited attention in birds. Motivated by a finding of MHC-dependent mate choice in the Leach's storm-petrel (Oceanodroma leucorhoa), we examined whether the chemical profiles of this highly scented seabird contain information about MHC genes. Whereas previous studies in birds examined non-volatile compounds, we used gas chromatography-mass spectrometry to measure the volatile compounds emitted from feathers that potentially serve as olfactory infochemicals about MHC and coupled this with locus-specific genotyping of MHC IIB genes. We found that feather chemicals reflected individual MHC diversity through interactions with sex and breeding status. Furthermore, similarity in MHC genotype was correlated with similarity in chemical profiles within female-female and male-female dyads. We provide the first evidence that volatile chemicals from bird feathers can encode information about the MHC. Our findings suggest that olfaction likely aids MHC-based mate choice in this species and highlight a role for chemicals in mediating genetic mate choice in birds where this mode of communication has been largely overlooked.

Using stable isotope (δ13C, δ15N) values from feces and breath to infer shorebird diets.

The use of stable isotopes of carbon (δ13C) and nitrogen (δ15N) from feces and breath offers potential as non-destructive tools to assess diets and nutrition. How stable isotope values derived from breath and feces compare with those from commonly used tissues, such as blood fractions and liver, remains uncertain, including understanding the metabolic routing of dietary nutrients. Here, we measured δ13C and δ15N from feces and δ13C of breath from captive Red-necked Stints (Calidris ruficollis) and 26 species of wild-caught migratory shorebirds (n = 259 individuals) and compared them against isotopic values from blood and feathers. For captive birds fed either cereal- or fish-based diets, differences in δ13C between feces and lipid-free diet were small, - 0.2 ± 0.5‰ and 0.1 ± 0.3‰, respectively, and differences in δ15N, - 0.7 ± 0.5‰ and - 0.5 ± 0.5‰, respectively. Hence, δ13C and δ15N values from feces can serve as proxies for ingested proteinaceous tissues and non-soluble carbohydrates because isotopic discrimination can be considered negligible. Stable isotope values in plasma and feces were strongly correlated in wild-caught shorebirds, indicating feces can be used to infer assimilated macronutrients. Breath δ13C was 1.6 ± 0.8‰ to 5.6 ± 1.2‰ lower than bulk food sources, and breath C derived from lipids was estimated at 47.5% (cereal) to 96.1% (fish), likely underlining the importance of dietary lipids for metabolism. The findings validate the use of stable isotope values of feces and breath in isotopic assays to better understand the dietary needs of shorebirds.

Genomic characterization and production of antimicrobial lipopeptides by Bacillus velezensis P45 growing on feather by-products.

AIMS: To investigate the potential of novel Bacillus velezensis P45 as an eco-friendly alternative for bioprocessing poultry by-products into valuable antimicrobial products. METHODS AND RESULTS: The complete genome of B. velezensis P45 was sequenced using the Illumina MiSeq platform, showing 4455 protein and 98 RNA coding sequences according to the annotation on the RAST server. Moreover, the genome contains eight gene clusters for the production of antimicrobial secondary metabolites and 25 putative protease-related genes, which can be related to feather-degrading activity. Then, in vitro tests were performed to determine the production of antimicrobial compounds using feather, feather meal and brain-heart infusion (BHI) cultures. Antimicrobial activity was observed in feather meal and BHI media, reaching 800 and 3200 AU ml-1 against Listeria monocytogenes respectively. Mass spectrometry analysis indicates the production of antimicrobial lipopeptides surfactin, fengycin and iturin. CONCLUSIONS: The biotechnological potential of B. velezensis P45 was deciphered through genome analysis and in vitro studies. This strain produced antimicrobial lipopeptides growing on feather meal, a low-cost substrate. SIGNIFICANCE AND IMPACT OF STUDY: The production of antimicrobial peptides by this keratinolytic strain may represent a sustainable alternative for recycling by-products from poultry industry. Furthermore, whole B. velezensis P45 genome sequence was obtained and deposited.

Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway: Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N).

The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs -polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)-, as well as emerging OHCs -per- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)- were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013-2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25-215.90 ng g-1), 15 PCBs (4.19-430.01 ng g-1), 6 OCPs (1.48-220.94 ng g-1), 5 PBDEs (0.21-5.32 ng g-1) and 3 OPEs (4.49-222.21 ng g-1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle-owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife.

Factors influencing lead, mercury and other trace element exposure in birds from metal mining areas.

Non-ferrous metal mining is considered one of the largest sources of toxic metal released to the environment and may threaten ecosystems, notably biota. We explored how birds that inhabit non-ferrous metal mining sites are exposed to mercury, lead, and other trace elements by analyzing their feathers and verifying which factors may influence element concentrations in feathers. We sampled a total of 168 birds, representing 26 species, with different feeding habits and migration patterns in a non-polluted reference site and two historical metal mining areas: Almadén, which is considered one of the most heavily mercury-contaminated sites worldwide, and the Sierra Madrona mountains where lead has been mined since ancient times. The quantification of aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), thorium (Th), thallium (Tl), uranium (U), vanadium (V) and zinc (Zn) was performed by inductively coupled plasma mass spectrometry (ICP-MS). Feather analysis revealed contamination by Hg and Pb, in Almadén and Sierra Madrona, respectively. We found that granivorous birds had the lowest feather Hg levels compared to those found in omnivorous, insectivorous, and piscivorous species, whereas feather Pb was about twice as high in granivores and omnivores, than in insectivorous and piscivorous birds. We also found differences among study sites in 13 elements and confirmed the influence of feather age, migratory patterns of the birds, and external deposition of elements, on metal concentrations in the feathers. Our results highlight that despite the cessation of metal mining in the study areas, local avifauna are being exposed to Hg and Pb from abandoned mines and old tailings sites, indicating that appropriate measures are needed to protect biota from overexposure to these toxic metals.

Occurrence of rare earth elements in fledgelings of Thalasseus sandvicensis.

Rare Earth Elements (REEs) are increasingly exploited for crucial new technologies, and their massive use in the past decades has significantly increased their environmental concentrations. Although their effects have been extensively studied in vitro and in vivo in model species, little is known of their accumulation and potential toxic effects in wildlife, including waterbirds. In the present work, we measured the concentrations of REEs in feathers of young Sandwich tern (Thalasseus sandvicensis) about 16-20 days old to assess whether the accumulation of these elements may be a concern in Venice's Lagoon, one of the most important wetlands of the Mediterranean area for breeding and migrating birds. The REE concentrations detected in the Sandwich tern were the highest among those reported in the literature for bird's feathers (940.9 ± 223.0 ng g-1), although in the study area industrial activities related to REEs mining, processing and disposal are absent. In particular, Lanthanum (La) was more abundant in the feathers than other REEs and accounted for 73-97% of total REEs detected. Analysis of bird's food indicated that diet is a relevant route of exposure to REEs for young terns; however, concentration in fishes are relevantly higher than in the feathers for all REEs other than La. The study evidenced the need to collect more information concerning the occurrence of REEs both in the abiotic matrices (i.e. water and sediments) and in living organisms of different trophic levels to improve the general knowledge concerning the fate of REEs in the aquatic ecosystems.

Multiple trace elements exposure of Grey-cheeked Fulvettas Alcippe morrisonia, a nuclear member in bird mixed-species flocks, and implications for bioindicator.

Birds are vulnerable to metal pollution, which can serve as indicators of environmental safety monitoring. In this study, we evaluated three non-essential (Pb, Cd, and As) and two essential (Cu and Zn) trace elements of living (only feathers) and deceased (feathers and tissues) Grey-cheeked Fulvetta (Alcippe morrisonia) at a highly polluted mine tailings and a reference site. Five metal concentrations in the feathers of living Grey-cheeked Fulvettas were higher at the mine site. Among these, the levels of Cd and Pb in most feathers exceeded the threshold, resulting in an ecotoxicological concern. The correlation analysis suggested that feathers from Grey-cheeked Fulvettas might be useful bioindicators for local metal contamination assessment. The toxicological effects of trace metals on Grey-cheeked Fulvetta might affect its leadership ability. Therefore, understanding the effects of metal pollution on Grey-cheeked Fulvetta would show important practical implications for the conservation of bird communities.

Appealing Renewable Materials in Green Chemistry.

In just a few years, chemists have significantly changed their approach to the synthesis of organic molecules in the laboratory and industry. Researchers are encouraged to approach "greener" reagents, solvents, and methodologies, to go hand in hand with the world's environmental matter, such as water, soil, and air pollution. The employment of plant and animal derivates that are commonly regarded as "waste material" has paved the way for the development of new green strategies. In this review, the most important innovations in this field have been highlighted, paying due attention to those materials that have played a crucial role in organic reactions: wool, silk, and feather. Moreover, we decided to focus on the other most important supports and catalysts in green syntheses, such as proteins and their derivates. Different materials have shown prominent activity in the adsorption of metals and organic dyes, which has constituted a relevant scope in the last two decades. We intend to furnish a complete screening of the application given to these materials and contribute to their potential future utilization.

Composition of feathers and pulp of two broiler genotypes.

1. Cobb and Ross broilers (200 of each sex and breed) were fed four phases of diets ad libitum formulated with balanced protein to match their amino acid requirements throughout growth. Ten birds per genotype were sampled and euthanised at two-weekly intervals from 14 to 112 d of age. All feathers were dry-plucked from each of the seven tracts (specific skin areas) and pulp (the centre of the feather filament) was removed from primary and secondary remiges.2. Daily losses of feathers were collected from an additional 20 individually-caged broilers of each breed. These feathers were separated into natal down, contour feathers, remiges and rectrices and then pooled by type, sex and genotype to quantify water and protein contents. Only those feathers collected from male Cobb 500 MX broilers were analysed for amino acid content.3. Amino acid contents of feathers from the seven tracts were measured only in Cobb males on days 1, 28 and 70; for pulp on days 28 and 70; and for the four types of moulted feathers.4. Protein content on a dry matter basis remained relatively constant over all ages and tracts during growth. Water content decreased with age in both sexes and genotype. Lysine and methionine content in feathers decreased with age while cystine, valine, leucine and serine increased. Lysine, methionine and histidine levels were higher in pulp than in mature feathers whereas cystine and valine were higher in mature feathers than in pulp.5. These results, together with information about moulting patterns in broilers, enabled the effects of age of the bird and of the type of feather, to be taken into account when determining the rate of deposition of amino acids in feathers.

A First Record of Organochlorine Pesticides in Barn Owls (Tyto alba) from Portugal: Assessing Trends from Variation in Feather and Liver Concentrations.

We evaluated feathers as a non-destructive biomonitoring tool documenting organochlorine pesticides (OCP) in liver and checked possible trends in pesticide use in two areas based on OCP concentrations in barn owls (Tyto alba). We measured the concentrations of 16 OCP in 15 primary feathers and 15 livers from barn owl carcasses collected on roadsides in Tagus Valley and Évora regions, south Portugal. Total OCP mean concentration was 8 120 ng g-1 in feathers and 178 ng g-1 in livers. All compounds were detected in feathers while in livers δ-HCH, endosulfan sulphate, p,p'-DDT and p,p'-DDD were not detected. The high ß-HCH and heptachlor concentrations in feathers most likely derived from external endogenous contamination. P,p'-DDE was the OCP with the highest hepatic concentration. Both matrices indicated an exposure to recently released heptachlor. The differing OCP concentrations between Tagus Valley and Évora seem to reflect differences in land-use and pesticide use histories of the two locations, and/or faster degradation of OCP in the Tagus area.