Black Plumage Research Articles

Flight initiation distance differs among eumelanin‐based color morphs in feral pigeons

AbstractOrganisms facing anthropogenic activities usually exhibit phenotypic responses assumed to enhance coping with disturbance. These responses include a decreasing degree of reaction toward potentially risky situations (“behavioral tolerance”) with increasing disturbance. Though melanin is associated with many phenotypic traits, including pigmentation and behavior, the potential relationship between behavioral tolerance and melanin has never been explored. Such relationship may potentially result from either direct association between melanin and behavior (e.g., genetic correlation) or indirectly through a coloration‐dependent behavior‐modulating factor (e.g., differential predation or human preferences in cities toward color morphs). Feral pigeons (Columba livia) represent an ideal biological system to test for these hypotheses, due to their presence in cities worldwide, their considerable variation in eumelanin‐based coloration, ranging from white to black plumage, and their close proximity to humans. We measured Flight Initiation Distance (FID, classically used for behavioral tolerance assessment) of feral pigeons of 4 different eumelanin‐based color morphs in sites differing in their urbanization rate and pedestrian traffic within the restricted scale of a city center (Paris). Urbanization rate and pedestrian traffic had no effect on FID, maybe because of the small spatial scale considered. FID varied with eumelanin‐based coloration: white pigeons had lower FID (104.6 cm; i.e., higher behavioral tolerance) than darker morphs (232.3 cm for Blue bar, 184.4 cm for T‐pattern & Checker, and 181.8 cm for Spread color morphs). Though the exact underlying causes remain to be identified, we propose different possible mechanisms for this relationship that remain to be investigated in future work.

A selection breeding pattern for sexually dimorphic breast plumage color in Guangxi Yao chickens

The breast plumage color of Guangxi Yao chickens shows obvious sexual dimorphism, with roosters showing black and black with red, and hens displaying partridge and red. Black plumage in roosters is considered a sign of quality, necessitating the purification of plumage color. Here, we developed an effective method based on genetic variations within MC1R and plumage characteristics. We clarified the distribution of 5 single nucleotide polymorphisms (SNP) and 3 haplotypes (H1, H2, and H3) of MC1R gene, and revealed potential associations between haplotype H1 and black breast plumage in the F2 resource population derived from a backcross between Guangxi Yao and Yellow chickens. Subsequently, using H1/H1 diplotype roosters and hens to construct families (n = 1,244) notably increased the proportion of offspring with black plumage. Further analysis suggested that red plumage in hens may be the putative phenotype of black plumage in roosters, driven by haplotype H1 of the MC1R gene, as verified by genotype and phenotype analysis. As expected, we found that almost all male offspring of hens with red breast plumage showed black plumage. In short, we established a selection pattern based on the combination of black-plumage roosters and red-plumage hens can significantly purify the sexually dimorphic plumage color and improve the efficiency of breeding programs in Guangxi Yao chickens. Our findings provide a novel technical framework to accelerate the breeding process for plumage trait in poultry.

Genome-wide association study reveals 2 copy number variations associated with the variation of plumage color in the white duck hybrid population

Plumage color is an intuitive external poultry characteristic with rich manifestations and complex genetic mechanisms. In our previous study, we observed that there were more dark variations in plumage color in the F2 population derived from the hybridization of 2 white duck varieties. Therefore, based on the statistics of plumage color of 308 F2 populations, we further used the resequencing data of these individuals to detect copy number variations (CNVs) in the whole genome and conducted genome-wide association studies (GWAS) to determine the genetic basis related to plumage color traits. The CNV detection revealed 9,337 CNVs, with an average length of 15,950 bp and a total length of 142.02 MB, accounting for approximately 12.91% of the reference genome. The CNV distribution on the chromosomes was relatively uniform, and the number of CNVs on each chromosome positively correlated with the length of the chromosome. In the pure black plumage group, 2,101 CNVs were only identified, and 1,714 were specifically identified in the pure white plumage group. Ten CNVs were randomly selected for validation using quantitative real-time PCR, and 9 CNVs had the same CNV types as predicted, with an accuracy of 90%. Based on GWAS, we identified 2 CNVs potentially associated with plumage color variations, with the associated CNV regions covering 9 genes. Enrichment analysis of these 9 candidate genes showed significant enrichment of 3 pathways (ribosome biogenesis in eukaryotes, RNA transport, and protein export) and 17 gene ontology terms. Among these, VWA5A can downregulate MITF by binding to the regulatory factors SOX10. The occurrence of CNV may indirectly contribute to duck plumage color variation by affecting the regulatory factors of the switch gene MITF in the melanogenesis pathway. These findings have improved the understanding of the genetic basis of duck plumage color variation and have been beneficial for developing and using plumage color traits in subsequent poultry breeding.

Black-headed Ibis Threskiornis melanocephalus (Latham, 1790): a review on ecology, behavior, conservation and management

The specific epithet melanocephalus is derived from Greek words meaning "black" (melas) and "head" (kephalē), referring to the distinctive black plumage on the head and neck of the Black-headed Ibis. The Black-headed Ibis (Threskiornis melanocephalus) stands as a captivating symbol of avian grace amidst wetland habitats across Asia. With its distinctive black head contrasting against a white body, this elegant bird captivates both ornithologists and birdwatchers alike. In this review, we delve into the ecology, behavior, and conservation status of the Black-headed Ibis, shedding light on its significance in the avian world. It is a striking bird species belonging to the ibis family, Threskiornithidae. Known for its distinctive appearance and graceful appearance, this bird captivates observers across its range in South Asia, Southeast Asia, and parts of the Middle East. Threskiornis melanocephalus is commonly found in South Asia, Southeast Asia, and parts of the Middle East, where it inhabits freshwater marshes, flooded grasslands, and shallow lakes. While not globally threatened, this species faces localized threats such as habitat loss, pollution, and hunting, highlighting the importance of conservation efforts to safeguard its populations and their wetland habitats.1

Investigation into the association of FNDC1 and ADAMTS12 gene expression with plumage coloration in Muscovy ducks.

To elucidate the molecular genetic mechanisms underpinning feather color in Muscovy ducks. A cohort of 100 Muscovy ducks was meticulously selected for this research. Follicular tissues from ducks exhibiting black and white plumage served as the experimental samples. From these tissues, RNA and proteins were extracted for further analysis. The RNA underwent reverse transcription polymerase chain reaction amplification, followed by validation through western blot assays. The data revealed a significant upregulation in the expression of FN domain-containing protein 1 (FNDC1) and ADAMTS12 genes in Muscovy ducks with white plumage traits as opposed to those with black plumage traits. Specifically, individuals with pure white plumage demonstrated a markedly elevated expression of the FNDC1 gene in comparison to their pure black counterparts. Conversely, expression levels of the ADAMTS12 gene were found to be reduced in ducks with pure black plumage relative to those with pure white plumage. Notably, the expression patterns of FNDC1 and ADAMTS12 genes exhibited inconsistencies between mRNA and protein levels. This study offers significant insights into the molecular genetic mechanisms underlying feather color variation in Muscovy ducks. FNDC1 and ADAMTS12 could be considered potential targets for genetic manipulation or selective breeding strategies aimed at achieving specific feather color phenotypes in Muscovy ducks.

Production and morphological characteristics of Muscovy ducks (Cairina moschata) in Mekong delta, Vietnam

Abstract To meet the demands of an increasing population, protein sources from meat should be diverted. Muscovy duck is a potential protein source of high meat weight and quality for humans. The study tried to describe all information of production and morphological traits of local Muscovy ducks from 1-12 weeks old. This study involved 40 Muscovy ducks from the Mekong Delta, Vietnam, and showed that local male and female Muscovy ducks differed, with male ducks performing better in terms of growth rate, nutrients in meat. The typical morphological characteristics of local Muscovy ducks are black plumage for whole body with small spot white in wings. The highest body weight (BW) was 3,356±166.3 g/head for male ducks and 2,036±104.4 g/head for female ducks. The birds could grow up to 23.72-39.32 g/day from 1-12 weeks age and consume 99.02-153.9 g/head/day feed. Meat of male ducks accounts for 65.8% of live BW while female duck meat accounts for 67% of live BW. The nutritional composition of female ducks was almost the same with male ducks, especially crude protein, at > 21%. It could be concluded that male Muscovy ducks can be used more suitable for meat purposes.

Prevalence of Poultry Coccidiosis and its Associated Risk Factors in and around Haramaya District, Ethiopia

Aim To determine the prevalence of poultry coccidiosis and identify the risk factors associated with the occurrence of the disease. Method A cross-sectional study was conducted on poultry coccidiosis of local and Rhode Island Red, White Leghorns, Koekoek, and bovine brown exotic breeds from November 2017 to April 2018 in and around Haramaya district, Ethiopia. Fecal examination using flotation and McMaster counting techniques were used for qualitative and quantitative studies, respectively. The study also involved a questionnaire survey for the assessment of possible risk factors. Results From 450 chickens examined by floatation method to detect Eimeria oocysts the result revealed 122 (27.1%) of the chickens were found positive for coccidiosis. The prevalence of coccidiosis among different age groups shows (68/214=31.8%), (54/236=22.9%) of young and adults were positive respectively. The prevalence is found statistically significant with p<0.05 (p=0.034, χ2=4.493) between different age groups. Regarding the breed prevalence (61/333=18.3%), (61/117=52.1%) Chefe and Gebsima (barley plumage color); Horro, Jarso, and Keyi (red plumage color); Naked Neck and Netch (white plumage color); Tepi and Tikur (black plumage color). Local and exotic breeds were positive respectively and the difference is statistically significant p<0.05 (p=0.00, χ2=50.109) between breeds. The study indicated also (46/168=27.4%) male and (76/282=27%) female chickens were positive but the difference between sex groups is no statistically significant difference p>0.05. The prevalence of coccidiosis in chickens kept in different management systems showed that (62/305=20.3%), (60/145=41.4%) were positive from extensive and intensive systems respectively. The difference is a statistically significant p<0.05 (p=0.00, χ2=22.040) among managements. From all the infected chickens most of them (96.7%) were lightly infected (<10,000 oocysts). Conclusion Coccidiosis is a major problem in the farm with inadequate hygienic measures and factors such as age, breed, body conditions, and biosecurity which are the most common factors that contribute for the occurrence of coccidiosis. Therefore, appropriate control strategies should be designed considering important risk factors and focus should be given to biosecurity practices in the prevention and control of coccidiosis, and in addition, further studies are needed to be conducted to identify the prevalent Eimeria species for strategic control.

First record of brown plumage aberration in Indian Pied Starling (Gracupica contra) from India

Abstract Brown aberration in black plumage is defined by the progressive reduction of eumelanin in birds. The present report describes an observation of plumage with brown aberration in Indian Pied Starling (Gracupica contra) from the agricultural landscape of Shokliya village, Rajasthan, India. The observed individual exhibited browning in all the areas of the plumage that are normally black in this species, including the head, wing feathers, and tail feathers. However, feathers with no pigmentation remained white and unaffected. Genetic and dietary factors are thought to be major factors responsible for such aberrations in birds, but more research is needed to determine the exact reasons.

Genetic mapping identifies SNP mutations in MITF-M promoter associated with melanin formation in Putian black duck

The coloration of plumage in poultry species has substantial economic significance. Putian black ducks encompass 2 distinct strains characterized by black and white plumage variations resulting from selective breeding. This study aimed to identify the molecular mechanisms responsible for plumage coloration in these 2 distinct strains. A comprehensive genome-wide association study was conducted using DNA data sourced from a F2 segregating population, consisting of 71 individuals with black plumage and 39 individuals with white plumage, derived from these distinct 2 strains. This analysis revealed that 894 nucleotide polymorphisms and identified 58 candidate genes. Subsequent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes coenrichment analyses identified MITF as a key candidate gene implicated in melanin biosynthesis. Furthermore, extensive screening of significant polymorphic loci within MITF was carried out via mass spectrometry in 3 distinct populations: 100 individuals with black plumage and 100 individuals with white plumage from the F0 generation; and 50 with black plumage form the F1 generation). Eighteen candidate polymorphic loci were identified demonstrating significant associations with variations in black and white plumage. Notably, 8 of these loci were located within the 2,000 bp region upstream of MITF-M. To validate the critical regulatory role of MITF-M in black and white plumage formation, a dual-fluorescence reporter system was constructed, and dual-fluorescence activity was assessed. The results revealed that the fluorescence activity at wild-type sites (corresponding to black plumage) was significantly higher than that at the mutant-type sites (associated with white plumage) (P < 0.01). To corroborate the pivotal role of MITF-M in black and white plumage formation, qPCR was employed to evaluate the expression levels of various MITF variants in black and white feather bulbs. This analysis demonstrated that only MITF-M exhibited specific expression in black feather bulbs. These results elucidate the central role of polymorphic mutations within the MITF promoter region in the regulation of black and white plumage coloration in Putian black ducks. This study extends our understanding of mechanisms governing duck plumage coloration and provides valuable molecular markers for future research in duck production and breeding based on plumage coloration.

Identification of the Membrane-Associated Transporter Protein (MATP) Gene Polymorphism as Candidate Mutation for Albinism in Japanese Quail

A pigmentation abnormality could be due to genetic mutation and trigger a disease related pigmentation deficiency such as albino which might be caused by mutation in membrane-associated transporter protein gene (MATP). The aim of this study was to identify polymorphism in the MATP exon 3 in Japanese quail. A total of nine Japanese quail consisting three brown plumage quail, three black plumage quail, and three albino quail were used in this study. Blood samples were used to extract the genomic Deoxyribonucleic acid (DNA) and used to amplify exon 3 regions of the MATP by polymerase chain reaction (PCR). The PCR products were then sequenced and analyzed. A total of 10 mutations were found, of which three mutations, g.4460G&gt;A, g.4479G&gt;A, and g.4514T&gt;C, were within exon 3. These mutations were synonymous and non-synonymous. No specific mutation for albino was found in this study. In summary those mutations did not specifically determine albinism in Japanese quail.

Genetic fine-mapping reveals single nucleotide polymorphism mutations in the MC1R regulatory region associated with duck melanism.

Birds are among the most colourful terrestrial vertebrates, with various plumage colours and patterns. We conducted a genome-wide association study (GWAS) on an intercross F2 population of Pekin ducks and mallards (n=722) and identified a 1.57-Mb genetic region (Chr11: 20,176,480-21,750,101 bp) related to duck melanism. Fine mapping by linkage disequilibrium (LD) and FST analysis narrowed the final candidate region to a region of 22,500 bp (Chr11: 20,677,500-20,700,000 bp) including three coding genes, TCF25, MC1R and TUBB3. Combined with transcriptome and qRT-PCR analysis, MC1R was identified as the unique genetic locus responsible for black plumage in ducks, and it was significantly more highly expressed in the feather bulbs of black ducks. We also identified 52G > A (Chr11: 20,696,354G > A) and 376G > A (Chr11: 20,696,678G > A) mutations in the MC1R coding region that have been widely studied in ducks. In addition, structural variations (SVs) were screened by nanopore sequencing, and no significant SV was found to be associated with the duck black plumage trait. However, we identified four novel single nucleotide polymorphisms in the MC1R regulator region (Chr11: 20,678,412G > A, Chr11: 20,679,236G > A, Chr11: 20,692,496 A > G and Chr11: 20,692,791 A > G) that had a strong association with the black plumage phenotype of ducks and combined with potential changes in transcription binding affinities. The luciferase reporter gene assay demonstrated that Chr11: 20,678,412G > A and Chr11: 20,679,236G > A led to significant promoter activity changes. Our research emphasizes the importance of MC1R regulatory region mutation in determining the duck black plumage phenotype, and these results expand our understanding of the genetic mechanism underlying duck plumage colour.

Genome-Wide Association Study Reveals the Genetic Basis of Duck Plumage Colors.

Plumage color is an artificially and naturally selected trait in domestic ducks. Black, white, and spotty are the main feather colors in domestic ducks. Previous studies have shown that black plumage color is caused by MC1R, and white plumage color is caused by MITF. We performed a genome-wide association study (GWAS) to identify candidate genes associated with white, black, and spotty plumage in ducks. Two non-synonymous SNPs in MC1R (c.52G>A and c.376G>A) were significantly related to duck black plumage, and three SNPs in MITF (chr13:15411658A>G, chr13:15412570T>C and chr13:15412592C>G) were associated with white plumage. Additionally, we also identified the epistatic interactions between causing loci. Some ducks with white plumage carry the c.52G>A and c.376G>A in MC1R, which also compensated for black and spotty plumage color phenotypes, suggesting that MC1R and MITF have an epistatic effect. The MITF locus was supposed to be an upstream gene to MC1R underlying the white, black, and spotty colors. Although the specific mechanism remains to be further clarified, these findings support the importance of epistasis in plumage color variation in ducks.

The Growth Pattern of Brazilian Canela-Preta Chickens with Different Plumages Reared in Two Rearing Systems

Growth pattern is essential for economically efficient poultry production. In this study, we aimed to describe the growth curve of chickens of the Canela-Preta breed reared in two different rearing systems, considering their different plumage colors. Initially, 204 one-day-old male and female chicks were randomly distributed in confinement and semi-confinement (102 animals in each system) without separation by gender. The animals were individually identified by wing and foot plastic brands and were weighted every seven days. The body weight and age records were used to estimate the growth curves of the following factors using the Richards model: plumage color, gender, and rearing system. The likelihood ratio test was used to verify the equality of parameters and identify nonlinear models to compare the growth patterns of the evaluated groups. The growth pattern of Canela-Preta chickens changed as a function of gender, plumage color, and rearing system. Females with black plumage, black and gold hens, and males with black and white plumage showed greater sensitivity to changes in rearing systems. Within-breed selection strategies for specific colors can improve the use of growth pattern differences, improving production efficiency. Semi-confinement is suitable for rearing Canela-Preta chickens with any plumage color, as these animals meet the free-range poultry niche market requirements.

Egg Quality of Italian Local Chicken Breeds: I. Yield Performance and Physical Characteristics.

The aim of this study was to compare yield performance (from 39 to 50 weeks of age) and egg physical characteristics (at 50 weeks of age) of eight autochthonous chicken breeds of the Veneto region (Italy). Four white eggshell breeds, namely Padovana Camosciata (PA-C, chamois plumage), Padovana Dorata (PA-G, golden plumage), Polverara Bianca (PO-W, white plumage), and Polverara Nera (PO-B, black plumage), and four tinted eggshell breeds, namely Pepoi (PP), Ermellinata di Rovigo (ER), Robusta Maculata (RM), and Robusta Lionata (RL) from a conservation centre were considered in the trial. Significant differences (p < 0.05) among breeds were observed for yield performance and egg quality. From 39 to 50 weeks of age, the hen-day egg production was higher in PA-C and RM than in RL, and PO-W and ER were intermediate; PA-G, PO-B, and PP were the lowest. The hen-day egg production changed according to the age of the hens. From 39 to 42 weeks of age, ER showed the highest hen-day egg production and PA-G the lowest; from 47 to 50 weeks, PA-C, PO-W, and RM were the highest and PP the lowest. The tinted eggshell breeds, with the exception of PP, had higher egg weights than white eggshell breeds. PP egg weight was similar to PO-B. As regards the tinted eggshell breeds, RM eggs had the highest eggshell a* and b*, and PP the lowest. PA-C had the most spherical eggs, and PO-B and ER had the most ovoid eggs. PO-W and RM had the highest eggshell thickness and ER had the lowest. The highest eggshell ratio was observed for PO-W and PO-B, and the lowest for ER. The yolk-to-albumen ratio was higher in the white eggshell breeds than in PP, ER, and RL. ER had the highest Haugh units and PA-G the lowest. PO-W, PO-B, PA-C, PA-G, and ER had the lowest egg inclusions, and RL and RM the highest. Tinted eggshell eggs differed from white eggshell eggs by having higher meat spots. Results indicated that the eggs produced by the eight local chicken breeds differed according to the laying rate and a wide range of physical external and internal characteristics which allow the consumer to distinguish them for their genetic origin by the eggshell shape and colour, and to use them for different purposes to valorise poultry biodiversity.

Differentiation in poult plumage color of f1 progeny from crosses between white and black indigenous turkeys.

A study assessed the poult plumage color of F1 progeny from artificially inseminated crossings between white and black indigenous turkeys. 72 hens (32 black, 40 white) and 10 toms were used (5 black and 5 white). The turkeys were grouped into four treatments based on the breeding plans: T1 (White toms × White hens), T2 (Black toms × Black hens), T3 (White toms × black hens), and T4 (Black toms × White hens). Semen was harvested from five white toms, pooled, and inseminated into hens in T1 and T3. Semen harvested from five black toms were also pooled and inseminated into hens in T2 and T4. All inseminations were carried out immediately after collection, and each hen received a dose of 0.02 mL. Insemination was done for 2 consecutive days in week 1 and once weekly; eggs were collected and incubated weekly for 12 weeks. Poult plumage colors were monitored and recorded weekly after the first 28 d. Average fertility in each of the treatments 1 (99.63%), 2 (99.81%), 3 (99.84%), and 4 (99.27%) were not significantly (P > 0.05) different among the treatments. Hatchability was highest in T2 (72.54%) and least in T1 (57.67%). Percentage white plumage poults in treatments 1, 2, 3, and 4 were 88.73%, 31.61%, 58.15%, and 54.63%, respectively. Percentage black plumage poults in T1, T2, T3, and T4 were 6.97%, 33.04%, 15.26%, and 23.76%, respectively, while 4.30%, 35.35%, 26.57%, and 21.61% were percentage checkered plumage poults in T1, T2, T3, and T4, respectively. There was no significant (P > 0.05) difference in the percentage checkered obtained in T2, T3, and T4; percentage of white poult in T3 and T4; percentage of black poult in T3 and T1. The major determinant of poult plumage color concerning quantity was the plumage color of breeder tom semen used for insemination.

Semen characteristics and fertility response of crosses between white and black plumage indigenous turkeys under artificial insemination

Abstract Semen quality and fertility in crossbreeding between white plumage and black plumage indigenous turkey hens using artificial insemination were investigated. Eighty-two healthy indigenous turkeys, comprising 72 hens (Thirty-two black and forty white) and 10 toms (five black and five white) were used. The turkeys were grouped into four treatments based on the breeding plans: T1 (White toms X White hens), T2 (Black toms X Black hens), T3 (White toms X black hens) and T4 (Black toms X White hens). Semen was harvested from white toms, pooled, and inseminated at 0.02ml into hens in T1 and T3. Semen harvested from black toms were also pooled and inseminated at same dose into hens in T2 and T4. White tom semen quality parameters were 97%, 91%, 96%, and 532×106 cells/mL for mass activity, motility, livability, and sperm concentration, respectively. Black tom semen quality parameters were 91%, 93%, 95%, and 293×106 cells/mL for mass activity, motility, livability, and sperm concentration, respectively. Egg fertility were 99.63% in T1, 99.81% (T2), 99.84%(T3), and 99.27% (T4). Hatchability in T1, T2, T3, and T4 were 57.67%, 72.54%, 67.65%, and 64.82%, respectively. Besides sperm concentration, semen quality parameters and fertility in indigenous turkey were not affected by plumage colour

Candidate pigmentation genes related to feather color variation in an indigenous chicken breed revealed by whole genome data.

Chicken plumage color is an inheritable phenotype that was naturally and artificially selected for during domestication. The Baicheng You chicken is an indigenous Chinese chicken breed presenting three main feather colors, lavender, black, and yellow plumages. To explore the genetic mechanisms underlying the pigmentation in Baicheng You chickens, we re-sequenced the whole genome of Baicheng You chicken with the three plumage colors. By analyzing the divergent regions of the genome among the chickens with different feather colors, we identified some candidate genomic regions associated with the feather colors in Baicheng You chickens. We found that EGR1, MLPH, RAB17, SOX5, and GRM5 genes were the potential genes for black, lavender, and yellow feathers. MLPH, GRM5, and SOX5 genes have been found to be related to plumage colors in birds. Our results showed that EGR1 is a most plausible candidate gene for black plumage, RAB17, MLPH, and SOX5 for lavender plumage, and GRM5 for yellow plumage in Baicheng You chicken.

Genetic diversity in 10 populations of domestic Turkeys by using microsatellites markers

The domestic turkey is a native breed in danger of extinction due to the introduction of new breeds specializing in meat production and yield. Turkeys have lost some prominence in urban areas, and only certain breeds of turkeys are preserved in rural areas. Wild and domestic turkeys are different; rural or indigenous turkeys, with black plumage, were domesticated from Mexican turkeys and have been reproduced throughout Latin America. Some of them were taken to Europe in the 16th century and later arrived in North America, where they crossed with another wild species, from which the bronze turkey emerged: the ancestor of all commercial turkeys. The objective of the present work was to evaluate the genetic diversity in 10 populations of domestic turkeys worldwide by using breeds from Europe: Spain and Italy; America: Mexico, United States and Brazil; and the Near East: Iran and Egypt. A total of 522 blood samples of both sexes were collected from domestic turkey populations. Thirty-four microsatellites were used to obtain genetic parameters, and genetic diversity was evaluated. All microsatellites used were polymorphic, and a total of 427 alleles were detected across the 34 markers investigated. In this study, a mean number of 13.44 alleles was found. The four most diverse breeds were from the Andalusia, Mexico, United States, and wild populations, which had the highest mean heterozygosity expected (0.619, 0.612, 0.650, and 0.773) and heterozygosity observed (0.422, 0.521, 0.429, and 0.627), respectively. The MNT348 marker deviated from the HWE in all populations. Our study has shown that the populations close to the species origin are more diverse than those resulting from posterior expansions. Mexican birds were the most diverse, followed by the Spanish populations because Spain imported a large number of turkeys coming from America. Such information can be complementary to other genotypic data required to validate the evolutionary relationships among turkey populations.

Variation in Body Weight and Biometric Traits of Exotic (Nicholas White) and Nigerian Locally Adapted Turkeys Reared in Humid Tropics

The performance of animal in a given environment differs between and within species, breeds and strains and genotypes, as a result of genetic variation. A total of 200 turkeys comprising 50 exotic (Nicholas white) and 50 each of Nigerian locally adapted turkeys (black, white and lavender) was used to investigate genetic variation in body weight and some biometric traits of exotic turkey and Nigerian locally adapted turkey at the Turkey Breeding unit of the Teaching and Research Farm of Ambrose Alli University, Ekpoma Edo State, Nigeria. The growth performance of the experimental birds was recorded biweekly throughout the period of the experiment. Genotype had significant effect (p&lt;0.05) on body weight in all the weeks with exotic turkey consistently having higher (p&lt;0.05) body weight throughout the experiment. The black plumage colour turkey performed better in body weight than the other two plumage colours of Nigerian locally adapted turkeys but was not significant (p&gt;0.05). Similarly, exotic turkey has the highest (p&lt;0.05) body length, body height, wing length, wing span and thigh length in most of the weeks of the experiment. Among the Nigerian locally adapted turkeys, black plumage turkey performed better (p&lt;0.05) in most of the measured biometric traits than white and lavender plumage colour turkeys. The exotic turkey with higher body weight and biometric traits can be used to upgrade Nigerian locally adapted turkeys to obtain tropically adapted broiler turkey breed and also selection preferential should be given local black turkey for genetic improvement.

Genome-Wide Analysis Identifies Candidate Genes Encoding Feather Color in Ducks.

Comparative population genomics and genome-wide association studies (GWAS) offer opportunities to discover human-driven detectable signatures within the genome. From the point of view of evolutionary biology, the identification of genes associated with the domestication of traits is of interest for the elucidation of the selection of these traits. To this end, an F2 population of ducks, consisting of 275 ducks, was genotyped using a whole genome re-sequence containing 12.6 Mb single nucleotide polymorphisms (SNPs) and four plumage colors. GWAS was used to identify the candidate and potential SNPs of four plumage colors in ducks (white, spot, grey, and black plumage). In addition, FST and genetic diversity (π ratio) were used to screen signals of the selective sweep, which relate to the four plumage colors. Major genomic regions associated with white, spotted, and black feathers overlapped with their candidate selection regions, whereas no such overlap was observed with grey plumage. In addition, MITF and EDNRB2 are functional candidate genes that contribute to white and black plumage due to their indirect involvement in the melanogenesis pathway. This study provides new insights into the genetic factors that may influence the diversity of plumage color.