Feather Samples Research Articles

Plumage coloration differs between offspring raised in natural cavities and nestboxes

Abstract Most of our knowledge of secondary hole-nesting birds comes from populations breeding in human-provided nestboxes, yet these might differ from natural cavities in a number of parameters, including internal dimensions or microclimate, leading to differences in reproductive ecology. Here, we demonstrate differences in plumage coloration, an important visual signal of individual quality, in Blue Tit (Cyanistes caeruleus) and Great Tit (Parus major) nestlings raised in natural cavities and nestboxes. For this study, we collected feather samples over two breeding seasons and applied reflectance spectrophotometry to calculate color metrics. Carotenoid chroma was higher in nestbox-reared Blue Tits, whereas brightness was higher in nestbox-reared Great Tits (with a similar tendency for Blue Tits). The latter result might be explained by the better nutritional condition of Great Tit nestlings raised in nestboxes. Furthermore, we found no evidence for preference of adults expressing more elaborate plumage towards a specific cavity type in either species. Consequently, we assume that differences in nestling plumage reported here are driven by rearing conditions (nestboxes vs. natural cavities) and not by differences in plumage-based parental quality. Our study adds to the growing body of evidence confirming that anthropogenic environmental modifiers, such as nestboxes, might influence avian physiology and the resulting phenotype.

Trace elements and heavy metals in black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) in the southeastern United States.

Many vulture species worldwide are declining at alarming rates due to a variety of anthropogenic causes, including exposure to pollutants and pharmaceuticals through consumption of contaminated carrion. However, little is known about the extent to which vultures are exposed to various contaminants as well as toxicity thresholds for trace elements and heavy metals. Our objective was to quantify levels of trace elements and heavy metals within black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) tissues to determine the extent to which populations in the Southeastern United States are exposed to carrion that contains high levels of contaminants. We collected 34 black vulture liver samples and examined differences in trace element and heavy metal concentrations between sexes and age classes (adult and juvenile). Further, we collected 81 blood and 42 feather samples from additional black and turkey vultures and compared differences between species and age classes. We found similar element concentrations between juvenile and adult black vultures with the exception of Cu, where levels were higher in juveniles compared to adults. However, we did observe substantial differences in element concentrations between species for both blood and feather samples, with black vultures generally having higher concentrations of most elements. Our data revealed higher element levels in both species compared to toxicity thresholds found in other bird of prey species, such as blood and liver toxicity threshold suggestions for Pb poisoning in Falconiformes. Further, while average contaminant levels were generally low, extreme outliers were observed for some elements, including Pb, suggesting some individuals were exposed to high levels of potentially toxic elements. More research is needed to better understand contaminant exposure in black and turkey vultures across a broader geographic region, as well as elucidate toxicity thresholds and non-lethal impacts of contaminant exposure in these species.

A preliminary study on short- and medium-chain chlorinated paraffins in duck farms: Concentrations, distribution, and dietary exposure risks

Chlorinated paraffins (CPs) in poultry feed and the farm environment might bioaccumulate in poultry eggs. Unlike chickens, which are mostly raised in cages, ducks are commonly raised free range. This would expose ducks to CPs in the environment. However, information on the presence of CPs on duck farms is scarce. In the present study, samples of duck eggs, duck feathers, poultry feed, and soil were collected from 25 duck farms in South China. Forty-eight congener groups of short- and medium-chain CPs (SCCPs and MCCPs) were detected in the samples. Interestingly, relatively high concentrations of SCCPs and MCCPs were found in the duck feathers. The median concentrations of SCCPs and MCCPs in the duck eggs, feathers, feed and soil were: 46 and 18 ng/g wet weight, 2460 and 992 ng/g, 103 and 47 ng/g, and 24 and 10 ng/g dry weight, respectively. The dominant groups of SCCPs and MCCPs were C10Cl6–7 and C14Cl7–8, respectively. The close relationship between duck feathers and poultry feed indicated that the duck feathers might act as a bioindicator for the exposure of ducks to CPs. The margin of exposure approach was used to assess the health risk, with the results showing that the consumption of duck eggs posed a low risk to different age groups from exposure to SCCPs and MCCPs.

Distribution of the Quill Mite Bubophilus aluconis Parasitising Western Palaearctic Owls Belonging to the Genus Strix.

Background: The paper presents the results of studies on the distribution of the parasitic quill mite species Bubophilus aluconis (Acariformes: Syringophilidae) in the feather quills of the Western Palaearctic owls of the genus Strix, that is, tawny owl S. aluco, collected in Poland and Sweden, the Ural owl S. uralensis, from Poland, Sweden, and Finland, and the great grey owl S. nebulosa, from Sweden and Finland. The two latter species are new hosts for B. aluconis. Methods: Feather samples of the tawny owl, Ural owl, and great grey owl used in this study come from Prof. Marian Cieślak's private collection, which contains feathers of Western Palearctic birds of prey and owls. Each of the 77 tawny owl, 75 Ural owl, and 55 great grey owl specimens are represented either by whole dry wings or a full complement of flight feathers (primaries (P) and secondaries (S)) and tails (rectrices (R)). Particular types of feathers were coded as follows: Ps, Ss, R, primary greater upperwing coverts (PGUppC), secondary greater upperwing coverts (SGUppC), primary greater underwing coverts (PGUndrC), secondary greater underwing coverts (SGUndrC), uppertail coverts (UppTC), and undertail coverts (UndrTC). Results: The prevalence was relatively low for all of the examined birds, that is, 12% for S. uralensis (N = 79), 2.6% for S. aluco (N = 77), and 3.6% for S. nebulosa (N = 55). In total, we examined 37,260 flight feathers and coverts. The mite B. aluconis occupied only the inner S of the tawny owl, secondary greater under and upperwing coverts of the great grey owl, and inner Ss, primary and secondary upperwing coverts, UndrTC, and coverts from the scapulars of the Ural owl. Conclusion: We hypothesise that the absence of these parasites in the examined P, S, and R suggests that these feather types might be unsuitable for the mites due to their thick quill walls, preventing successful feeding.

Structure, variation and assembly of body-wide microbiomes in endangered crested ibis Nipponia nippon.

Limited knowledge of bird microbiome in the all-body niche hinders our understanding of host-microbial relationships and animal health. Here, we characterized the microbial composition of the crested ibis from 13 body sites, representing the cloaca, oral, feather and skin habitats, and explored assembly mechanism structuring the bacterial community of the four habitats respectively. The bacterial community characteristics were distinct among the four habitats. The skin harboured the highest alpha diversity and most diverse functions, followed by feather, oral and cloaca. Individual-specific features were observed when the skin and feathers were concentrated independently. Skin and feather samples of multiple body sites from the same individual were more similar than those from different individuals. Although a significant proportion of the microbiota in the host (85.7%-96.5%) was not derived from the environmental microbiome, as body sites became more exposed to the environment, the relative importance of neutral processes (random drift or dispersal) increased. Neutral processes were the most important contributor in shaping the feather microbiome communities (R2 = .859). A higher percentage of taxa (29.3%) on the skin were selected by hosts compared to taxa on other body habitats. This study demonstrated that niche speciation and partial neutral processes, rather than environmental sources, contribute to microbiome variation in the crested ibis. These results enhance our knowledge of baseline microbial diversity in birds and will aid health management in crested ibises in the future.

The survey on the circulation of Marek’s disease virus in local chickens in Tra Vinh province, Vietnam

The study was conducted to determine the circulation of Marek’s disease virus in local chickens in Tra Vinh province. A total of 343 feather follicle samples were collected from 49 unvaccinated chicken flocks for Marek disease in Tra Vinh City, Cang Long, Tra Cu, and Tieu Can districts. The samples were tested by polymerase chain reaction to detect specific meq gene of Marek’s disease virus serotype 1 (MDV-1). Information on hygiene and vaccination programs was also collected. The results showed that 45 out of 343 samples were positive for MDV-1, accounting for 13.12%. The prevalent MDV-1 in chickens in Cang Long was 17.85%, followed by Tra Vinh City (15.38%). The same prevalence of MDV-1 (9.52%) was recorded in chickens in the Tieu Can and Tra Cu districts. The differences in the prevalence of MDV-1 in chickens among surveyed sites were not statistically significant (P>0.05). There was no significant difference in the prevalence of MDV-1 by chicken breeds. The prevalence of MDV-1 in chickens from 3 to 6 months old was highest at 34.04%, followed by chickens from 1 to less than 3 months old (11.06%) and older 6 months of age (5.71%). The risk of MDV -1 infection in vaccinated chickens against Avian influenza, Newcastle disease and Gumboro disease was lower than that of unvaccinated chickens (OR=0.277, P=0.044). The combination of sanitation and disinfection decreased the risk of MDV-1 infection in chickens (OR=0.502;P=0.031).

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.

Utility of Feathers for Avian Influenza Virus Detection in Commercial Poultry.

The present study evaluated the potential utility of feather samples for the convenient and accurate detection of avian influenza virus (AIV) in commercial poultry. Feather samples were obtained from AIV-negative commercial layer facilities in Iowa, USA. The feathers were spiked with various concentrations (106 to 100) of a low pathogenic strain of H5N2 AIV using a nebulizing device and were evaluated for the detection of viral RNA using a real-time RT-PCR assay immediately or after incubation at -20, 4, 22, or 37 °C for 24, 48, or 72 h. Likewise, cell culture medium samples with and without the virus were prepared and used for comparison. In the spiked feathers, the PCR reliably (i.e., 100% probability of detection) detected AIV RNA in eluates from samples sprayed with 103 EID50/mL or more of the virus. Based on half-life estimates, the feathers performed better than the corresponding media samples (p < 0.05), particularly when the samples were stored at 22 or 37 °C. In conclusion, feather samples can be routinely collected from a poultry barn as a non-invasive alternative to blood or oropharyngeal-cloacal swab samples for monitoring AIV.

Modified phenol chloroform protocol for genomic DNA extraction from keratinous tissue

DNA extraction enables the isolation and purification of genetic material by physical-chemical methods. There are specific protocols for different types of samples as animal and plant tissue. However, there are variations and particularities according to the nature of the fabric, such as the high presence of keratin. Thus, the present work aimed to develop and optimize a DNA extraction protocol from feather based on the Phenol-Chloroform method. Feather samples werw collected from 9 birds native to the Amazon region for the genetic material extraction. The DNA was precipitated with isopropanol and washed with 70% ethanol. Subsequently, the pellet was disolved in the TE buffer. The results indicated satisfactory concentrations for post-extraction molecular biology techniques such as PCR. The protocol showed a significant reduction in the incubation time to 1 hour compared to other protocols aimed at feather samples. Addition proteinase K to the lysis solution was the main factor that led to the optimization of the extraction time. The A260/230 and A260/280 absorbance ratios indicated the quality of the extracted DNA being close to what expected. Therefore, the results demonstrate the potential protocol use for molecular biology studies in birds from feather samples. However volume of phenol-chloroform and 70% ethanol can still be adjusted to suit the type sample.

Feathers, eggs, and blood as bioindicators of heavy metals and their impact on DNA damage in captive Pavo cristatus

ABSTRACT Heavy metals and their genotoxic effects in captive Indian Peafowl (Pavo cristatus) residing in various regions of Punjab, Pakistan, specifically, Wildlife Park Bahawalpur (WPB), Jallo Wildlife Park Lahore (JWPL), and Wildlife Park Murree (WPM) were evaluated in blood, feathers, eggshell and egg content samples. The Single-cell gel electrophoresis (Comet) assay was performed to evaluate DNA damage. The results showed that the concentration of Cr was significantly high (P < 0.05) in Blood (3.79 µg/g), Feather (4.87 µg/g), Egg shell (51.02 µg/g) and Egg Content (13.59 µg/g) samples of Jallo Wildlife Park Lahore followed by Pb, Mn, Ni and Co. The highest (P < 0.05) metal accumulation was found in eggshell samples due to its porous structure as compared to other samples. Likewise region-wise analysis showed that Jallo Wildlife Park Lahore appeared to be more polluted than WPB and WPM. Indian Peafowl kept at WPM and JWPL exhibited higher levels of genotoxicity compared to the birds kept at WPB. This disparity can be attributed to the increased exposure to pollution and heightened stress experienced by the peafowl in the former two locations. This study concluded that among all the three study sites of Punjab, the WPB is most suitable for housing captive animals and birds.

Avian nuptial plumage coloration changes differently when exposed to urban and rural areas

Avian plumage coloration could be altered by external factors like dust accumulation, but the effect of environmental conditions on such post-moult colour changes are poorly studied. Here, we investigated how exposure to the atmosphere in habitats of differing anthropogenic pressures modifies UV/blue structural plumage coloration — a sexually selected trait in eastern bluebirds Sialia sialis. We collected feather samples from live birds and distributed them in three types of habitats: (i) urban roads with low traffic, (ii) urban roads with high traffic, and (iii) rural roads with low traffic. After 4 weeks, the brightness of feathers decreased in all types of habitats-resulting in less-ornamented coloration. Changes in UV and blue chroma, however, varied with habitat type; chroma decreased in urban areas (becoming less ornamented), but increased in rural locations (becoming more ornamented). According to physiological models of avian colour vision, however, these changes in coloration tended to be below perceptual thresholds. Our results underscore the importance of how human activity can influence plumage colour of individual birds during the period between moult cycles which could have an impact on avian visual signalling. The study opens venues for further studies focusing on how the optical properties of specific airborne particles can influence coloration of wild-living animals.Significance statementPlumage coloration plays an important role in avian visual communication. In addition to moult-based change, coloration may change between moult cycles due to exposure to external factors like, for example, dust accumulation. Ecological factors modifying a passive plumage change, however, remains poorly studied. We collected samples of structurally coloured feather from a species wherein plumage colour is sexually selected and exposed them to outdoor conditions. We demonstrate that UV/blue chroma of coloration changes differently in urban and rural habitats. It increased in rural and decreased in urban areas. On the other hand, brightness decreased in both habitat types. Using physiological models of avian colour vision, however, we found that these colour changes were likely not perceptible to birds. Our study provides the first evidence that changes in coloration of fully grown feathers may be habitat dependent.

Species and seasonality can affect recent trends in beak and feather disease virus prevalence in captive psittacine birds

Beak and feather disease virus (BFDV) is globally distributed in psittacine birds. BFDV is considered a key threat to biodiversity because it has the ability to transmit and shift between host species. Data from captive psittacine birds can help to identify potential risk factors for viral transmission management. Generalized Linear Models (GLM) were used to examine the association of sample type, species, and season on the prevalence of BFDV in captive exotic birds in Thailand.In this study, the overall prevalence of BFDV was 8.2 %, with 346 of 4243 birds being positive. The prevalence in feather samples (12.1 %) and pooled (dried blood and feather) samples (15.4 %) was higher than that in the dried blood samples (4.8 %). A GLM test revealed that the sample type, species, and season were significant factors influencing the prevalence of BFDV. Based on the model, two species (blue-eyed cockatoo; Cacatua ophthalmica, and ring-necked parakeet; Psittacula krameri) were associated with higher BFDV prevalence. By studying the seasonal BFDV prevalence, we can gather important insights into the environmental factors that contribute to its spread. The higher prevalence observed during the wet season suggest a possible affect between BFDV prevalence and environmental factors such as heavy rainfall and humidity. In conclusion, our analysis of the trends in BFDV prevalence offers valuable insights into the prevalence or distribution of BFDV in the studied population. By monitoring BFDV prevalence, identifying high-risk species, and understanding seasonal patterns, we can develop targeted management approaches to control the spread of the virus. This information is crucial for mitigating the impact of BFDV on aviculture.

Minimally Invasive Sampling Methods for Molecular Sexing of Wild and Companion Birds

Birds are highly social and must be paired in order to increase their welfare. Most bird species are monomorphic; therefore, molecular sexing helps provide appropriate welfare for birds. Moreover, early sex determination can be of great value for bird owners. The aim of this study was to demonstrate that sex identification in birds achieved using molecular methods and samples collected via minimally invasive methods is fast, efficient, and accurate. A total of 100 samples (29 paired samples of feathers and oral swabs and 14 tripled samples of feathers, oral swabs, and blood) from 43 birds were included in this study, as follows: wild birds (Falconiformes, Accipitriformes, landfowl—Galliformes, waterfowl—Anseriformes) and companion birds (Passeriformes, Psittaciformes—large-, medium-, and small-sized parrots). Amplification of CHD1-Z and CHD1-W genes was performed via conventional PCR. The results obtained from feathers were compared to those obtained from oral swabs and to those obtained from blood samples, where applicable. The obtained results show that all types of samples can be used for molecular sexing of all studied bird species. To the best of our knowledge, the present study reports, for the first time, molecular sex identification in Red Siskin (Carduelis cucullata) and Goldfinch (Carduelis carduelis major). For higher accuracy, our recommendation is to use minimally invasive samples (oral swabs and feathers) and to test both types of samples for each bird instead of blood samples.

Efficiency of DNA Extractions Methods from Pigeons and Cockatiels Feathers

This study aimed to compare different DNA extraction methods to achieve higher amounts and purity levels from molted feathers of pigeons (Columba livia f. domestica) and cockatiels (Nymphicus hollandicus). We evaluated 226 animals consisting of 202 pigeons and 24 cockatiels for these purposes. We performed three commercially available DNA extraction kits to isolate DNA from the feather samples. These kits were compared regarding DNA yield and quality depending on the different applications made during the isolation. DNA concentration (ng/mL) and absorbance ratio (260/280) were measured using a Nanodrop spectrophotometer. Kruskal-Wallis test with the Dunn’s post hoc comparison was performed for the statistical comparisons. The mean DNA concentration was the highest in isolation with the kit C. Among three commercial kits, statistically significant differences were observed concerning nucleic acid concentration (ng/µL) (P

Multi-Stage Transcriptome Analysis Revealed the Growth Mechanism of Feathers and Hair Follicles during Induction Molting by Fasting in the Late Stage of Egg Laying.

Induced molting is a common method to obtain a new life in laying hens, in which periodic changes in feathers are the prominent feature. Nevertheless, its precise molecular mechanism remains unclear. In this study, feather and hair follicle samples were collected during fasting-induced physiological remodeling for hematoxylin-eosin staining, hormone changes and follicle traits, and transcriptome sequencing. Feather shedding was observed in F13 to R25, while newborns were observed in R3 to R32. Triiodothyronine and tetraiodothyronine were significantly elevated during feather shedding. The calcium content was significantly higher, and the ash content was significantly lower after the changeover. The determination of hair follicle traits revealed an increasing trend in pore density and a decrease in pore diameter after the resumption of feeding. According to RNA-seq results, several core genes were identified, including DSP, CDH1, PKP1, and PPCKB, which may have an impact on hair follicle growth. The focus was to discover that starvation may trigger changes in thyroid hormones, which in turn regulate feather molting through thyroid hormone synthesis, calcium signaling, and thyroid hormone signaling pathways. These data provide a valuable resource for the analysis of the molecular mechanisms underlying the cyclical growth of hair follicles in the skin during induced molting.

Fluctuation of the prevalence of beak and feather disease virus in captive psittacines in Iran.

Beak and feather disease virus (BFDV) is one of the most life-threatening viral agents infecting parrot species. In this study, we investigated fluctuation in the prevalence of beak and feather disease virus (BFDV) in captive psittacines in Iran. Two series of feather samples from different psittacine species, received between July 2019 and July 2021 (n = 1009) and between July 2021 and July 2022 (n = 2020), were examined for the presence of BFDV using the PCR method, and the host species distribution and temporal prevalence of BFDV within populations were calculated. The results showed a total viral prevalence of 26.86% and 26.88% within sample series 1 and 2, respectively. By examining both sample series, the prevalence of BFDV was found to be thehighest (P < 0.05) in Nymphicus hollandicus and thelowest (P < 0.05) in Psittacus erithacus, Myiopsitta monachus, Pyrrhura molinae, and Aratinga solstitialis. The viral prevalence was significantly higher (P < 0.05)within the series 1than theseries 2 samples only in Nymphicus hollandicus. Within series 2, the viral prevalence was significant (P < 0.05) in samples from Nymphicus hollandicus collected in March. This study indicates significant prevalence of BFDV in captive Nymphicus hollandicus populations and suggests that the fluctuation in the prevalence of BFDV could be due to the combined influence of host-species and temporal factors.

AN EVALUATION OF SYLVIIDAE SPECIES IN THE TRANSPORT OF POLLEN: A CASE STUDY OF İSTANBUL

During pollination, pollen grains can be transported to distant distances by various factors such as wind, insects, birds, and reptiles. While there have been numerous studies on pollen transportation by birds in Europe, there is a lack of research concerning the pollen grains transported by bird species in Turkey. In this context, we explored the role of Sylviidae species in pollination and identified the plant species whose pollen is transported by these birds. The temporary ringing station located at İstanbul University-Cerrahpaşa Avcılar Campus was selected as the study area and a total of 35 feather samples were collected from individuals of Sylvia atricapilla (Linnaeus), S. borin (Boddaert), Curruca communis (Latham), C. cantillans (Pallas), C. curruca (Linnaeus) and C. melanocephala (Gmelin) captured at station. Based on the analysis of pollen found on the feather samples, it was determined that the pollen found in 18 feather samples of Curruca curruca and Sylvia atricapilla provided pollen belonging to Pinus (Pine), Aesculus (Horse chestnut), Prunus (Plum), Spiraea (Spiraea), Quercus (Oak), Fraxinus (Ash) and Melia (Bead tree). The most commonly determined pollen on C. curruca were of Prunus (63.5%), while the least common were of Aesculus (0.9%). The most commonly determined pollen on S. atricapilla were of Melia (48.1%), while the least common were of Crocus (0.2%). The presence of pollen among the food sources of Sylviidae species during spring, the synchronization between the arrival time of birds in the study area during migration and the pollination period of the determined plant taxa, and the prevalence of these taxa in the study area suggest that S. atricapilla and C. curruca may be contributing to pollination.

Factors influencing mercury exposure in Arctic-breeding shorebirds.

Mercury (Hg) pollution remains a concern to Arctic ecosystems, due to long-range transport from southern industrial regions and melting permafrost and glaciers. The objective of this study was to identify intrinsic, extrinsic, and temporal factors influencing Hg concentrations in Arctic-breeding shorebirds and highlight regions and species at greatest risk of Hg exposure. We analyzed 1094 blood and 1384 feather samples from 12 shorebird species breeding at nine sites across the North American Arctic during 2012 and 2013. Blood Hg concentrations, which reflect Hg exposure in the local area in individual shorebirds: 1) ranged from 0.01-3.52 μg/g ww, with an overall mean of 0.30 ± 0.27 μg/g ww; 2) were influenced by species and study site, but not sampling year, with birds sampled near Utqiaġvik, AK, having the highest concentrations; and 3) were influenced by foraging habitat at some sites. Feather Hg concentrations, which reflected Hg exposure from the wintering grounds: 1) ranged from 0.07-12.14 μg/g fw in individuals, with an overall mean of 1.14 ± 1.18 μg/g fw; and 2) were influenced by species and year. Most Arctic-breeding shorebirds had blood and feather Hg concentrations at levels where no adverse effects of exposure were predicted, though some individuals sampled near Utqiaġvik had Hg levels that would be considered of concern. Overall, these data increase our understanding of how Hg is distributed in the various shorebird breeding areas of the Arctic, what factors predispose Arctic-breeding shorebirds to Hg exposure, and lay the foundation for future monitoring efforts.

Associations of polymorphisms in prolactin and dopamine receptor D2 genes with reproductive traits on Silkie chicken

The Silkie chicken (Gallus gallus domesticus Brisson) is one of domestic chicken breeds with commercial rearing and breeding potentials for egg production. Prolactin (PRL) and dopamine D2 receptor (DRD2) are potential genes associated with reproductive traits in chickens. This study was conducted to analyze the association of PRL and DRD2 insertion/deletion (Indel) polymorphisms with chicken reproductive traits in Silkie chickens. A total of 380 hens from 16-40 weeks of age were used, with each one being placed in a separate cage. DNA isolation was performed using feather samples, and genotypes were detected using the Indel technique. Two polymorphisms consisting of 24 base pair (bp) Indel in the promoter region of the PRL gene and 22 bp Indel in the promoter region of the DRD2 gene were identified. At both sites, the Indel polymorphisms did not follow the Hardy-Weinberg equilibrium. In addition, with the exception of total eggs over 23 weeks of laying in the PRL gene, the analysis revealed no association between these polymorphic loci and any traits collected. In conclusion, birds with the DD genotype produced the maximum egg yield (73.6 eggs/hen), whereas those with the II genotype produced approximately 9 fewer eggs (64.1 eggs/hen), resulting in laying rates of 45.7% and 40.1%, respectively. For enhancing the egg-laying capacity of Silkie chickens via selective breeding, opting for DD birds with DD genotype of PRL Indel is highly recommended.

Recent Review on the Extraction and Qualitative Assay of Cysteine and Other Amino Acids from Vellore Feather Waste and Molecular Docking Studies of Cysteine for Pharmacological Applications.

Products produced from waste are a relatively recent innovation. Feather substrates are abundant in keratin content and improper disposal can cause ecosystem contamination. However, these pollutants can be transformed into value-added products for industrial application. Physical, chemical and cutting-edge microbiological methods were utilized for decomposing keratin and aid in the identification andestimation of amino acids from poultry feather wastes. These beneficialapproaches are receiving more attention due to their retrieval of harmless and value addedbyproducts. These keratin-based compounds are used widely in pharmaceutical, livestock feed, fertilizer, and a variety of other industrial sectors. Since keratin is primarily consisting of amino acids, it can be utilized to affirm and estimate the amino acids in these feather substrates. This study primarily highlights the various methodologies employed for the qualitative estimation of amino acids in feather waste samples and the inhibitory activity of keratinase enzyme by EDTA and pepstatin in order to accumulate amino acids for drug delivery purpose and their importance in various pharmaceutical industries. In addition to that, molecular docking studies of cysteine with many standard pharmaceutical drugs like acetaminophen, pethidine, methylphenidate, carbamazepine, cillin and amlodipine were performed using autodock to demonstrate how cysteine greatly reduces conventional drug toxicity and its side effects.