Feather Concentrations Research Articles

Lead exposure is correlated with reduced nesting success of an urban songbird

Lead exposure is a concern in urban ecosystems, with physiological and behavioral effects well documented in humans. Wildlife inhabiting urban ecosystems are also exposed to lead, yet little work has documented the sublethal effects of lead exposure in urban wildlife. We studied northern mockingbirds (Mimus polyglottos) in three neighborhoods of New Orleans, Louisiana, two with high soil lead and one with low soil lead, to better understand how lead exposure may influence mockingbirds' reproductive biology. We monitored nesting attempts, measured lead concentrations in blood and feathers of nestling mockingbirds, documented egg hatching and nesting success, and assessed rates of sexual promiscuity in relation to neighborhood soil lead levels. We found that nestling mockingbirds’ blood and feather lead levels reflected the soil lead levels of their neighborhoods and nestling blood lead levels were similar to those of adult mockingbirds in the same neighborhoods. Nest success, as evaluated by daily nest survival rates, was higher in the lower lead neighborhood. Clutch sizes varied substantially across neighborhoods, but rates of unhatched eggs did not covary with neighborhood lead levels, suggesting that other drivers are influencing variation in clutch sizes and hatching success in urban habitats. At least one-third of nestling mockingbirds were sired by an extra-pair male, and there was no relationship between extra-pair paternity rates and neighborhood lead levels. This study provides insight on how lead contamination may influence reproduction in urban-dwelling wildlife and suggests that nestling birds could serve as useful bioindicators of lead levels in urban neighborhoods.

Metal concentrations in feathers of red-legged cormorants (Phalacrocorax gaimardi) and sources of plastic in a nesting colony from northern Chile

Mining industry is increasing the concentrations of heavy metals in coastal ecosystems of northern Chile. The presence of plastic in the nests of red-legged cormorants could be acting as a vector of metal presence in their organism. Here we analyze the source of plastic in the nests of cormorants by characterizing the abundance and type of marine debris in beaches and sea surface and the concentrations of eight metals in their feathers. Plastic was present in overall sampled nests and floating and beach debris are not the main sources of plastic to the nests. Overall analyzed metals were present in the cormorants in the following order: Zn > Cu > Se > Pb > Cd > As > Hg > Cr and Se, Cd and Pb concentrations were above the toxic limit. Further studies should investigate the potential adverse effects that plastics and metals presence may cause in this nesting colony.

Long-term monitoring of exposure to toxic and essential metals and metalloids in the tawny owl (Strix aluco): Temporal trends and influence of spatial patterns

As a result of regulatory decisions, atmospheric deposition of most toxic metals and metalloids (MEs) has decreased in Europe over the past few decades. However, little is known about how this reduction translates into exposure at higher trophic levels in the terrestrial environment where temporal trends may be spatially heterogeneous due to local current or legacy sources of emissions (e.g., industry) or long-range transport of elements (e.g., marine transport). The aim of this study was to characterize temporal and spatial trends of exposure to MEs in terrestrial food webs using a predatory bird, the tawny owl Strix aluco, as a biomonitor. Toxic (Al, As, Cd, Hg, Pb) and essential/beneficial (B, Co, Cu, Mn, Se) elemental concentrations were measured in feathers of nest-captured females from 1986 to 2016, extending a previous study published over the time-series 1986–2005 (n = 1051), in a breeding population in Norway. A drastic decline over time was shown for the toxic MEs (−97 % for Pb, −89 % for Cd, −48 % for Al, and −43 % for As) except Hg. The beneficial elements B, Mn, and Se showed oscillations but an overall decline (−86 %, −34 %, and −12 %, respectively) whereas the essentials Co and Cu did not exhibit significant trends. The distance to potential sources of contamination influenced both the spatial patterns of concentrations in owl feathers and their temporal trends. The accumulation of As, Cd, Co, Mn and Pb was overall higher in the vicinity of sites recorded as polluted, and a greater temporal decrease of As, B, and Cd concentrations was found in the areas of further distance to polluted sites. The decrease of Pb concentrations was sharper further from the coast during the 1980s than in coastal areas, while the opposite was observed for Mn. The levels of Hg and Se were higher in coastal areas, and Hg temporal trends differed according to the distance to the coast. This study highlights the valuable insights provided by long-term survey of wildlife exposure to pollutants and landscape indicators to reveal regional or local patterns and detect unexpected events, data that are crucial for regulation and conservation of ecosystem health.

Trace elements in migratory species arriving to Antarctica according to their migration range

The levels of eighteen trace elements (TEs) were evaluated in association with stable isotopes (δ15N, δ34S, and δ13C) in feathers and eggs of five migratory species breeding on the Antarctic Peninsula to test the factors that influence their exposure to contaminants. The feathers of seabirds migrating to the Northern Hemisphere (South polar skua) have concentrations (mean ± SD, μg. g−1) of Li (1.71 ± 2.08) and Mg (1169.5 ± 366.8) one order of magnitude higher than southern migrants, such as Snowy sheathbill Li (0.01 ± 0.005) and Mg (499.6 ± 111.9). Feathers had significantly higher concentrations for 11 of a total of 18 metals measured compared to eggs. South polar skua have higher concentrations of all TEs in eggs compared to antarctic tern. Therefore, the present study showed that migration and trophic ecology (δ15N, δ13C, and δ34S) influence Fe, Mn, Cu, and Se concentrations in feathers of Antarctic seabirds. The concentrations of Cu, Mn, Rb, Zn, Pb, Cd, Cr are higher than previously reported, which may be due to increased local and global human activities.

Nutrients and seabird biogeography: Feather elements differ among oceanic basins in the Southern Hemisphere, reflecting bird size, foraging range and nutrient availability in seawater

AbstractAimBiodiversity hotspots in wide‐ranging marine species typically overlap with regions of high productivity, which are often associated with nutrient‐rich waters. Here we investigate how element concentrations in feathers vary among highly mobile seabirds in global seabird biodiversity hotspots.LocationSouthern Hemisphere.Time periodContemporary.Major taxa studiedFifteen species in the order Procellariiformes.MethodsWe collected data on the concentration of 15 elements in feathers for 253 seabirds sampled across Australia and New Zealand and compared the “fingerprint” of micronutrient element profiles to feathers of related seabirds from global hotspots using principal component analysis (PCA), cluster analysis and permutational analysis of variance (PERMANOVA).ResultsBreast feather concentrations of some elements, including aluminium, iron, cobalt, chromium, manganese, nickel, arsenic and cadmium, were tens‐to‐hundred‐fold higher in smaller (<400 g) than larger species (≥400 g). We suggest these results reflect the dominance of pelagic crustaceans in the diet of smaller seabirds, blooms of which are influenced by input of limiting ocean nutrients. Cluster analysis revealed three broad groups of feather elements: large seabirds, and small seabirds in each of the South Pacific and South Atlantic Ocean basins. High concentrations of some elements in feathers match seawater availability and are detectable in lower‐trophic feeding seabirds with local movements. Conversely, the element fingerprints of longer‐distance, higher‐trophic foragers, including albatrosses, do not match availability in seawater at the collection site.Main conclusionsThe feather element concentrations of shorter‐range foraging, lower‐trophic feeding seabirds vary significantly among ocean basins, reflecting availability in seawater, while longer‐range, higher‐trophic species do not. We propose that geographically diverse availability of micronutrients, in addition to primary productivity, may play an underrecognized role in seabird biogeography and intra‐hemispheric migration, though more research is needed. This study has important implications, considering the role of element availability in supporting biodiversity hotspots for dispersive marine predators and for the designation of protected areas.

Keratinases from Streptomyces netropsis and Bacillus subtilis and Their Potential Use in the Chicken Feather Degrading

Feathers are the most prevalent agricultural waste generated by chicken farms, polluting the environment and wasting protein resources as a result of the accumulation of large amounts of feathers. Therefore, keratinase-producing microorganisms represent a promising potential technique for the degradation of feather waste. Streptomyces netropsis A-ICA and Bacillus subtilis ALICA, previously isolated from the rhizosphere of desert plants (Larrea tridentata and Prosopis juliflora) respectively, were assessed for their feather-degradation ability. Keratinase activity was optimized using various parameters, including incubation time, pH, temperature, and feather concentration. The maximum keratinase activity of S. netropsis A-ICA and B. subtilis ALICA (113.6 ± 5.1 and 135.6 ± 4.1 U/mL) was obtained at the 5th and 3rd day of incubation with initial pH of 7.0 and 7.5 at 25 and 30 °C, and 1% (w/v) of chicken feather, respectively. Under the optimized conditions, the concentration of soluble protein in the feather hydrolysate reached 423.3 ± 25 and 565.3 ± 7.7 µg/mL, with feathers weight loss of 84 ± 2 and 86± 1.5% by S. netropsis A-ICA and B. subtilis ALICA, respectively. The highest disulphide bond reductase activity reached 10.7 ± 0.4 and 10.96 ± 1.1 U/mL, after five and three days of inoculation with S. netropsis A-ICA and B. subtilis ALICA, respectively. Furthermore, the antioxidant activity of feather protein hydrolysate obtained by S. netropsis A-ICA and B. subtilis ALICA was evaluated using DPPH radical-scavenging activity, which exhibited a significant antioxidant potential with an IC50 value of 0.8 and 0.6 mg/mL. The 3D models of detected keratinases in both strains showed high similarity with subtilisin family. Further, the docking results clarified the importance of GSG and VVVFTP domains in B. subtilis and beta-keratin, respectively. The present study revealed the keratinolytic potential of S. netropsis A-ICA and B. subtilis ALICA in chicken feather degradation, which have potential application value and may be exploited as supplementary protein and antioxidant in animal feed formulations.

Experimental evidence for clothianidin deposition in feathers of house sparrows after ingestion of sublethal doses treated seeds.

Bird feathers are commonly used to assess environmental contamination by chemical pollutants. However, although neonicotinoid insecticides are widely applied worldwide, feathers have rarely been used to survey the contamination by neonicotinoids in birds. To investigate whether clothianidin, one compound of the neonicotinoid class, is deposited into birds’ feathers, we conducted an experiment with 56 wild male and female house sparrows dispatched in 7 aviaries. During this experiment, house sparrows were fed with certified organic seeds treated with clothianidin at an estimated concentration of 0.25 μg/g BW per day and per individual. We collected blood samples and plucked four tail feathers at the onset of the experiment to confirm that no birds were previously exposed to clothianidin. 35 days later, we collected blood samples and the newly grown feathers. Before exposure, a small number of birds showed very low clothianidin concentrations in plasma and feathers. After exposure, the plasma and the newly grown feathers of all birds contained clothianidin. Clothianidin concentrations in feathers were similar in both sexes, but the plasma of males contained clothianidin at higher concentrations than that of females. Our results confirm that ingested clothianidin transits in the plasma and is deposited in feathers during their growth. They also suggest substantial individual variation in the amounts of clothianidin transiting in the plasma and being deposited in feathers that may reflect variation in metabolism and/or access to food in relation to sex, social hierarchy and group dynamics. Whether increasing levels of exposure translate linearly or non-linearly (e.g. saturation process) into increasing clothianidin concentrations in bird plasma and feathers remains to be investigated. To conclude, these results confirm the relevance of using feathers to biomonitor the presence of neonicotinoids, but the relationship between the level of exposure and the concentrations found in feathers remains to be established.

Carryover effects of winter mercury contamination on summer concentrations and reproductive performance in little auks

Many animals migrate after reproduction to respond to seasonal environmental changes. Environmental conditions experienced on non-breeding sites can have carryover effects on fitness. Exposure to harmful chemicals can vary widely between breeding and non-breeding grounds, but its carryover effects are poorly studied. Mercury (Hg) contamination is a major concern in the Arctic. Here, we quantified winter Hg contamination and its carryover effects in the most abundant Arctic seabird, the little auk Alle alle. Winter Hg contamination of birds from an East Greenland population was inferred from head feather concentrations. Birds tracked with Global Location Sensors (GLS, N = 28 of the total 92) spent the winter in western and central North Atlantic waters and had increasing head feather Hg concentrations with increasing longitude (i.e., eastward). This spatial pattern was not predicted by environmental variables such as bathymetry, sea-surface temperature or productivity, and needs further investigation. Hg concentrations in head feathers and blood were strongly correlated, suggesting a carryover effect of adult winter contamination on the consequent summer concentrations. Head feather Hg concentrations had no clear association with telomere length, a robust fitness indicator. In contrast, carryover negative effects were detected on chick health, as parental Hg contamination in winter was associated with decreasing growth rate of chicks in summer. Head feather Hg concentrations of females were not associated with egg membrane Hg concentrations, or with egg volume. In addition, parental winter Hg contamination was not related to Hg burdens in chicks’ body feathers. Therefore, we hypothesise that the association between parental winter Hg exposure and the growth of their chick results from an Hg-related decrease in parental care, and needs further empirical evidence. Our results stress the need of considering parental contamination on non-breeding sites to understand Hg trans-generational effects in migrating seabirds, even at low concentrations.

Fipronil and its metabolites in chicken feather: residue analysis, depletion study, and application analysis of pollution sources in laying hens.

A method based on a multi-mechanism impurity adsorption and ultra-performance liquid chromatography-tandem mass spectrometry was established to detect fipronil and four of its metabolites in chicken feathers. This method was successfully applied to the depletion study of fipronil in feathers of laying hens. Fipronil and two metabolites were found in feathers during treatment. Fipronil concentrations in feathers increased during medication and then regularly decreased during withdrawal, and they were still detected on the 14th day after withdrawal. High residue concentrations were also present in feathers on day 23 of the experimental period. Pollution sources of fipronil can be inferred on the basis of the residue ratio of fipronil metabolites from different pollution modes. Result shows that feathers were an effective matrix for residue monitoring and risk analysis of fipronil in animals and the environment.

Spatial variations in winter Hg contamination affect egg volume in an Arctic seabird, the great skua (Stercorarius skua)

Knowledge of the ecology and at-sea distribution of migratory species like seabirds has substantially increased over the last two decades. Furthermore, an increasing number of studies have recently focused on chemical contamination of birds over their annual cycle. However, the understanding of the combined effects of spatial movements and contamination on seabirds’ life-history traits is still scarce. During winter, seabirds can use very different areas, at the large-scale. Such overwintering strategies and distribution may expose individuals to contrasting environmental stressors, including pollutants. Here, we studied the winter distribution and contamination with mercury (Hg), and their combined effects on reproduction, in a great skua (Stercorarius skua) population breeding in Bjørnøya, Svalbard. We confirmed that individuals of this specific population overwinter in three different areas of the North Atlantic, namely Africa, Europe and northwest Atlantic. The highest Hg concentrations in feathers were measured in great skuas wintering off Europe (Linear Mixed Models - mean value ± SD = 10.47 ± 3.59 μg g −1 dw), followed by skuas wintering in northwest Atlantic (8.42 ± 3.70) and off Africa (5.52 ± 1.83). Additionally, we found that female winter distribution and accumulated Hg affected the volume of their eggs (Linear Mixed Models), but not the number of laid and hatched eggs (Kruskal-Wallis tests). This study provides new insights on the contamination risks that seabirds might face according to their overwinter distribution and the possible associated carry-over effects.

Total and methylmercury concentrations in nocturnal migratory birds passing through Mount Ailao, Southwest China

Despite growing concerns over mercury (Hg) accumulation in birds in recent decades, little is known about Hg exposure in nocturnal migratory birds. Here, total mercury (THg) and methylmercury (MeHg) were detected in the feathers of nocturnal migratory birds (n = 286, belonging to 46 species) passing through Mount Ailao in Southwest China. The stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) were also determined to clarify the effects of trophic position, foraging guild, and foraging behavior on Hg bioaccumulation. Our results show that the THg and MeHg concentrations varied by two orders of magnitude among all nocturnal migratory birds investigated, with the lowest values (THg: 0.056 mg kg−1; MeHg: 0.038 mg kg−1) in the Asian koel (Eudynamys scolopaceus) and the highest (THg: 12 mg kg−1; MeHg: 7.8 mg kg−1) in the hair-crested drongo (Dicrurus hottentottus). Waterbirds showed higher δ15N values and higher THg and MeHg concentrations than songbirds, and the Hg concentrations in piscivorous species were significantly higher than those in herbivores, omnivores, and insectivores. Significant effects of foraging guilds (Kruskal–Wallis one-way ANOVA, p < 0.001) and foraging behaviors (Kruskal–Wallis one-way ANOVA, p < 0.001) on the Hg concentrations in migratory bird feathers were detected. A risk assessment indicated that approximately 7.0% of individuals were at moderate (2.4–5.0 mg kg−1) to high (>5.0 mg kg−1) risk of Hg exposure, and were therefore vulnerable to adverse physiological and behavioral effects. A long-term monitoring campaign during the migratory period is highly recommended to better understand the bioaccumulation of Hg in these nocturnal migratory bird populations over time.

CHICKEN FEATHER DEGRADATION BY KERATINOLYTIC ASPERGILLUS SPECIES ISOLATED FROM FEATHER WASTE DUMPING SOIL

Slaughterhouses and poultry processing units worldwide dispose of huge amount of chicken feathers that accumulate as solid waste in the environment and cause serious consequences. Keratinases are a group of enzymes, produced by microorganisms have the ability to degrade tough recalcitrant keratin that is abundantly present in chicken feathers. Soil sample was collected from a feather dumping site at Virudhunagar (9° 35' 13.9524'’ N Latitude and 77° 57' 5.1516'’ E Longitude), Tamil Nadu, India. Soil sample was serially diluted, inoculated on to feather meal agar plates and incubated at 37 °C for 7 days to isolate keratinolytic fungal strains. The isolated strains were screened for proteolytic activity on skim milk agar for 8 days and three better strains were identified based on morphology, mycelial growth, and structure of hyphae using lactophenol cotton blue staining and confirmed by ITS primer sequencing method as Aspergillus niger, Aspergillus terreus and Aspergillus flavus respectively. Different range of pH (7 to 11), temperature (25 to 45 °C), substrate (bovine serum albumin, feather, peptone and gelatin) and feather concentration (0.5g, 1g, 1.5g and 2g) were tested to find out the optimum conditions for the growth and keratin degradation of the chosen fungal strains. The temperature and feather concentration for the optimum growth of A. niger, A. terreus and A. flavus were 25 °C and 1.5g, 45 °C and 1g and 30 °C and 1.5g respectively. All three Aspergillus species exerted better growth at pH 9 and with bovine serum albumin as the substrate.

Perfluoroalkylated compounds in the eggs and feathers of resident and migratory seabirds from the Antarctic Peninsula

In this study, we investigated factors that influence the differences in exposure of perfluoroalkyl acids (PFAAs) from eight species of Antarctic seabirds, including Pygoscelis penguins, Stercorarius maccormicki, and Macronectes giganteus. We analyzed the relationship between foraging ecology (based on δ13C, δ15N, and δ34S values) and PFAAs accumulated in eggs and breast feathers. Ten out of 15 targeted PFAAs were detected in eggs compared to eight in feathers. Mean ∑PFAA concentrations in feathers ranged from 0.47 in P. antarcticus to 17.4 ng/g dry weight (dw) in S. maccormicki. In eggs, ∑PFAA concentrations ranged from 3.51 in P. adeliae to 117 ng/g dw in S. maccormicki. The highest concentrations of most PFAAs were found in trans-equatorial migrators such as S. maccormicki, probably due their high trophic position and higher concentrations of PFAAs in the Northern Hemisphere compared to the Southern Hemisphere. Based on stable isotopes correlations, our results suggest that the trophic position (δ15N) and the foraging area (δ13C and δ34S) influence PFAAs concentrations in Antarctic seabirds. Our results point to the possibility that long-distance migratory birds may have as bio-vectors in the transport of pollutants, including PFCAs, in Antarctic environments, although this must be further confirmed in future studies using a mass balanced approach, such as extractable organofluorine (EOF).

Stable Mercury Trends Support a Long-Term Diet Shift Away from Marine Foraging in Salish Sea Glaucous-Winged Gulls over the Last Century.

Marine predators are monitored as indicators of pollution, but such trends can be complicated by variation in diet. Glaucous-winged gulls (Larus glaucescens) have experienced a dietary shift over the past century, from mainly marine to including more terrestrial/freshwater inputs, with unknown impacts on mercury (Hg) trends. We examined 109-year trends in total mercury (THg) and methylmercury (MeHg) concentrations in glaucous-winged gull feathers (1887-1996) from the Salish Sea. Adult flank feathers had higher MeHg concentrations than immature feathers, and males head feathers had higher THg concentrations than females. Overall, we found no evidence of a trend in feather MeHg or THg concentrations over time from 1887 to 1996. In the same individuals, δ15N, δ13C, and δ34S declined over time in gull feathers. In comparison, egg THg concentrations declined from 1970 to 2019 in two species of cormorants, likely reflecting decreases in local Hg sources. We conclude that diet shifts through time may have countered increased Hg deposition from long-range transport in glaucous-winged gulls. The lack of Hg trends over time in glaucous-winged gull feathers provides additional support that these gulls have decreased the amount of marine forage fish in their diet.

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 120ngg-1 in feathers and 178ngg-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 β-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.

Variation Among Species and Populations, and Carry-Over Effects of Winter Exposure on Mercury Accumulation in Small Petrels

Even in areas as remote as the Southern Ocean, marine organisms are exposed to contaminants that arrive through long-range atmospheric transport, such as mercury (Hg), a highly toxic metal. In previous studies in the Southern Ocean, inter-specific differences in Hg contamination in seabirds was generally related to their distribution and trophic position. However, the Blue Petrel (Halobaena caerulea) was a notable exception among small seabirds, with higher Hg levels than expected. In this study, we compared the Hg contamination of Blue Petrels and Thin-billed Prions (Pachyptila belcheri), which both spend the non-breeding season in polar waters, with that of Antarctic Prions (Pachyptila desolata), which spend the winter in subtropical waters. We collected body feathers and blood samples, representing exposure during different time-frames. Hg concentrations in feathers, which reflect contamination throughout the annual cycle, were related to δ13C values, and varied with ocean basin and species. Blue Petrels from breeding colonies in the southeast Pacific Ocean had much higher feather Hg concentrations than expected after accounting for latitude and their low trophic positions. Both Hg concentrations and δ15N in blood samples of Blue Petrels were much lower at the end than at the start of the breeding period, indicating a marked decline in Hg contamination and trophic positions, and the carry-over of Hg burdens between the wintering and breeding periods. Elevated Hg levels may reflect greater reliance on myctophids or foraging in sea-ice environments. Our study underlines that carry-over of Hg concentrations in prey consumed in winter may determine body Hg burdens well into the breeding season.

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.

Presence of fipronil and metabolites in eggs and feathers of ornamental hens from Italian family farms

In Italy, hens for beauty contests are bred in backyard farms, characterized by the presence of few heads and self-consumption of animal products. According to law, these small farms are not subject to animal registration on national databases and are not submitted to official inspections by official veterinarians. Fipronil belongs to the category of banned drugs for animals intended for human consumption. However, being sold the formulation for pets both online and on the market, its illicit use by farmers is conceivable. In this study, egg and feather samples were collected from 19 farms spread all over Italy, and the concentration of fipronil and its main metabolites (fipronil-sulfone, hydroxy-fipronil, fipronil-desulfinyl, and fipronil-sulfide) were analysed by HPLC-HRMS. Two farms out of 19 reached a positivity rate of 80% for fipronil; five farms reached a positivity rate of 80% for fipronil-sulfone. Analysed separately, egg albumens and yolks showed a positive correlation for the concentration of both fipronil (r 0.92) and fipronil-sulfone (r 0.74), with higher concentrations recorded in yolk due to the lipophilicity of the molecules. The risk characterization shows that the intake of these eggs is not harmful to human health: the EDI (estimated daily intake) calculated on the data we collected was below the ADI (acceptable daily intake). Fipronil-desulfinyl was detected in higher concentrations in feathers, likely as a photodegradation product of the parent molecule.

Age features and reference intervals for the concentrations of some essential and toxic elements in laying hens.

Background and Aim:Micronutrient imbalances pose a severe threat to the health and productivity of livestock and poultry. In this regard, a further stage in feeding science development will control and optimize the intake of mineral substances, including determining the elemental composition in some biosubstrates. One of these biosubstrates can be a feather. However, the amount of available information on the content of trace elements in laying hens is limited, complicating the laboratory data interpretation. Therefore, this study established reference intervals for the concentrations of the main essential and toxic elements in laying hens in different periods of ontogenesis.Materials and Methods:The study was conducted on clinically healthy Hisex Brown laying hens at the age of 10 (n=150), 30 (n=150), 120 (n=150), 150 (n=150), and 210 (n=150) days. All examined birds were born and raised on the territory of the South Ural biogeochemical province of Russia. The sampling of feathers was carried out by plucking the flight feathers of the wing. Inductively coupled plasma dynamic reaction cell mass spectrometry determined the elemental composition of the feather according to 25 parameters.Results:The results showed that at the minimum age (10 days), the highest concentrations of chemical elements were observed in laying hens. Subsequently, as they grew older, in the period from the 30th to the 120th day, there was a significant decrease in these indicators. Later, from the 120th to the 150th day, a statistically significant increase in concentrations was replaced. Little growth and relative concentration stability were observed in the last part of the experiment (150-210 days). Chemical element concentrations in feathers were computed in reference ranges for each age group.Conclusion:The calculated ranges of chemical element concentrations in laying hens can be used to compile norms for their content in the body; however, it is worth noting that these ranges can vary depending on the biogeochemical province of breeding and the bird’s age.

Comparison of stress biomarkers in laying hens raised under a long-term multiple stress condition

The objective of the current experiment was to compare various stress biomarkers including the heterophil to lymphocyte ratio (H:L ratio) in blood and the corticosterone (CORT) concentrations in feathers, claws, and egg yolk and to find the potential stress biomarkers in laying hens exposed to a long-term multiple stress condition. A total of 24 Hy-Line Brown laying hens at 47 wk of age were allotted to 2 distinct conditions including normal condition (NC) and multiple stress condition (MC) with 8 replicated cages. In NC treatment, 8 hens were raised individually in the cage (0.16 m2/hen) under the temperature of 21 ± 0.6°C. In MC treatment, 16 hens were raised with 2 hens per cage to decrease space allowance (0.08 m2/hen) and the temperature was maintained at 31 ± 1.6°C. The experiment lasted for 8 wk. The common diets and water were fed on an ad libitum basis during the experiment. Results indicated no interactions between stress conditions and duration of stress exposure for all measurements. Hens in MC treatment had a greater (P < 0.01) blood H:L ratio than those in NC treatment. The greater (P < 0.05) H:L ratio for MC treatment was observed at all weeks. Hens in MC treatment had greater (P < 0.05) feather CORT concentrations than those in NC treatment. Feather CORT concentrations were increased (P < 0.05) with duration of the experiment. However, stress conditions did not influence claw CORT concentrations. A tendency (P = 0.081) was observed for greater yolk CORT concentrations in MC treatment than in NC treatment. In conclusion, the H:L ratio in blood and CORT concentrations in feathers and egg yolks are considered potential stress biomarkers in laying hens exposed to stress conditions, although each measurement has its respective limitations. However, CORT concentrations in the claw appear to be insensitive to a long-term stress exposure.