Feather Length Research Articles

Investigation of Glandula Uropygialis in Different Avian Species Using Morphometric and Histological Methods.

The aim of this study was to identify the glandula uropygialis's macroanatomical and histological structure in male and female birds (stork, goose, eagle, pigeon, crow and sparrowhawk) that belong to different populations. A total of 58 specimens were used in the study. The study materials were delivered to our laboratory by nature conservation and national parks, and no animals were euthanised for this study. The longitudinal and transversal lengths, dorsoventral heights and feather length of the glandula uropygialis and papilla uropygialis were measured with a digital calliper. Haematoxylin-eosin and Masson trichrome staining were performed for histological examinations. The shape of the glandula uropygialis was found to be pear-shaped in pigeons and sparrowhawks, heart-shaped in geese, kidney-shaped in eagles and oval-fascule-shaped in storks. In the crow, the shape of the glandula uropygialis was different from the other species in that it was located dorso-caudally. Histomorphological examination of the glands of these species revealed that the gland generally consisted of two lobes, right and left, surrounded by connective tissue from the outside. The parenchyma of these lobes consisted of tubulo-alveolar secretory glands with a radial arrangement from the periphery to the centre. The glands within the lobes differed from the periphery to the centre and although the general histomorphological appearance was similar between bird species, some differences were observed between species. Similar stromal structure was observed in all bird species evaluated in the study. However, the reticular connective tissue forming the roof of the gland was found to be more developed in pigeons, especially in Masson's trichroma staining. The degenerative layer in the glands was more prominent in the eagle, followed by the goose and crow. Although a common general histological structure was observed among bird species, simple histomorphological differences were found between these formations, but no differences were found between the sexes. The results obtained will be compared with the findings of the aves class and will provide a data source for this special gland specific to birds. It is thought that the results obtained may help to determine the functional properties of the gland and contribute to the science of ornithology.

Effects of L-Methionine and DL-Methionine on Growth Performance, Methionine-Metabolizing Enzyme Activities, Feather Traits, and Intestinal Morphology of Medium-Growing, Yellow-Feathered Chickens between 1 and 30 Days of Age.

This experiment investigated the effects of L-Methionine (L-Met) on growth performance, Met-metabolizing enzyme activity, feather traits, and small intestinal morphological characteristics, and compared these with DL-Methionine (DL-Met) for medium-growing, yellow-feathered broilers during the starter phase. Furthermore, the aim was to provide recommendations for the appropriate dietary Met levels in feed. A total of 1584 1-d broilers were randomly divided into 11 treatment groups with six replicates of 24 birds each: basal diet (CON, Met 0.28%), basal diet + L-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%), and basal diet + DL-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%). The total trial period was 30 days. Compared with broilers fed the basal diet, those fed 0.04 to 0.20% supplemental Met had higher final body weight (FBW), average daily feed intake (ADFI), average daily gain (ADG), and lower feed-to-gain ratio (F: G) (p < 0.05). Compared with DL-Met groups, the L-Met group had higher FBW and ADG (p < 0.05). The relative bioavailability (RBV) of L-Met in ADG of 1-30 d was 142.5%. Chicks fed diets supplemented with L-Met had longer fourth primary feather lengths compared to birds fed the control and diets supplemented with DL-Met (p < 0.05). Compared to the control, birds supplemented with DL-Met or L-Met had an increased moulting score (p ≤ 0.05). Chicks fed diets supplemented with L-Met had lower activities of methionine adenosyl transferase (MAT) compared to those fed the basal diet or supplemented with DL-Met (p < 0.05). Chicks supplemented with either DL-Met or L-Met had higher activities of cystathionine β-synthase (CBS) than those fed the basal diet (p < 0.05). Compared with the control, chicks fed diets supplemented with either DL-Met or L-Met had an enhanced level of albumin in plasma (p < 0.05). There were no obvious differences in the plasma content of uric acid and total protein among the treatments (p > 0.05). Chicks fed diets supplemented with either DL-Met or L-Met had higher villus height and V/C in the duodenal than chicks fed the basal diet (p < 0.05). The jejunum morphology was not affected by either L-Met or DL-Met supplementation (p > 0.05). Therefore, dietary supplementation with DL-Met or L-Met improved the growth performance, feather traits, and intestinal morphological characteristics of medium-growing, yellow-feathered broiler chickens aged 1 to 30 d by decreasing the enzyme activities of Met methylation (MAT) and increasing the enzyme activities of the sulfur transfer pathway (CBS), and supplementation with L-Met showed a better improvement compared with DL-Met. The relative efficacy of L-Met to DL-Met was 142.5% for ADG of yellow-feathered broilers. The appropriate Met levels for medium-growing, yellow-feathered broilers are between 0.36~0.38% (supplementation with DL-Met) or 0.32~0.33% (supplementation with L-Met) when based on ADG and feed-to-gain ratio.

Identification of candidate genes associated with primary feathers of tianfu nonghua ducks based on Genome-wide association studies

The primary feathers of ducks have important economic value in the poultry industry. This study quantified the primary feather phenotype of Nonghua ducks, including the primary feathers' length, area, distribution of black spots, and feather symmetry. And genome-wide association analysis was used to screen candidate genes that affect the primary feather traits. The genome-wide association study (GWAS) results identified the genetic region related to feather length (FL) on chromosome 2. Through Linkage disequilibrium (LD) analysis, candidate regions (chr2: 115,246,393-116,501,448 bp) were identified and were further annotated to 5 genes: MRS2, GPLD1, ALDH5A1, KIAA0319, and ATP9B. Secondly, candidate regions related to feather black spots were identified on chromosome 21. Through LD analysis, the candidate regions (chr21: 163,552-2,183,853 bp) were screened and further annotated to 47 genes. Among them, STK4, CCN5, and YWHAB genes were related to melanin-related pathways or pigment deposition, which may be key genes affecting the distribution of black spots on feathers. In addition, we also screened 125 genes on multiple chromosomes that may be related to feather symmetry. Among them, significant SNPs on chromosome 1 were further identified as candidate regions (chr1: 142,118,209-142,223,605 bp) through LD analysis and annotated into 2 genes, TGFBRAP1 and LOC113839965. These results reported the genetic basis of the primary feather from multiple phenotypes, and offered valuable insights into the genetic basis for the growth and development of duck feathers and feather color pattern.

A long tail of truth and beauty: A zigzag pattern of feather formation determines the symmetry, complexity, and beauty of the peacock’s tail

Background Darwin assumed that the peacock’s long train was maladaptive and was the indirect effect of selection by female mate choice based on the train’s beauty. While a relationship between the feathers’ elaborate features and mating success has been shown, what features of the train females are attracted to remains controversial. Methods We used museum specimens to examine the anatomical plan underlying feather development responsible for the symmetry of the train. We developed a model based on an alternate arrangement of primordial feather buds during development and locations of concentric circles of symmetric eyespot distribution using the pattern seen on the train as a template. Results We observed a zigzag pattern of feather follicles that determined both the number and the hexagonal arrangement of eyespots on the train. Our model explained not only the alternate arrangement of feathers on the train but also the arrangement of the concentric color rings of the eyespots. While the zigzag pattern explains the symmetry, complexity, and structural beauty of the peacock’s train, it also precludes variation in eyespot number except by annual addition of new rows of feathers as a function of age. Conclusions Since eyespot number and feather length are developmentally correlated and an asymptotic function of a male’s age, their effects on female choice would be confounded and inseparable, and male vigor would be a crucial factor affecting male fitness. Females may not always choose males with the largest number of eyespots, as older males may lack vigor. We propose a multimodal model of female choice where females see eyespot and train size not as separate traits but as one complex trait combining both. The new model may be able to explain conflicting results and why eyespot number alone may not be sufficient to explain female choice.

Discrimination among similarly colored goose species in federal harvest surveys

AbstractEach year in the United States, fall‐winter (sport) harvests of goose species are estimated from federal surveys coordinated by the United States Fish and Wildlife Service, including the Migratory Bird Harvest Survey to estimate total goose harvest and the Parts Collection Survey (PCS) to estimate the species and age composition. For the PCS, randomly selected hunters collect tail and wing feathers of each goose shot during the hunting season, and then biologists determine the age class and species of each sample at organized events (Wingbees) in each of the 4 flyways (Pacific, Central, Mississippi, and Atlantic). For similarly colored goose species, cackling (Branta hutchinsii) versus Canada (B. canadensis) geese (dark geese) and Ross's (Anser rossii) versus snow (A. caerulescens) geese (light geese), different protocols evolved among Wingbees to differentiate samples into groupings of management interest, leading to difficulties in estimating species‐level harvests among the 4 flyways or nationally. We conducted a study among the United States flyways during 2019–2022 to derive thresholds of central tail feather length to discriminate between dark geese and between light geese. We compared morphological‐ and genetic‐based approaches. There was support for 2 distinct mitochondrial DNA (mtDNA) clades in dark and light geese, but only dark goose clades corresponded with central tail feather lengths (morphological size and species identification). Derived thresholds for central tail feather lengths of dark geese in the 3 westernmost flyways using genetic‐based species' discrimination were 145 mm for adults and 134 mm for juveniles, approximately 13 mm and 9 mm less, respectively, than thresholds using morphological‐based species' discrimination. There was limited ability to discriminate light geese based on either mtDNA or central tail feather lengths. We suggest managers use our derived thresholds based on genetic‐based species' discrimination to classify dark goose PCS samples. More advanced genome analyses should be conducted before changing current Wingbee protocols for light geese. Lastly, we encourage more studies to incorporate genetic analyses to complement morphological discrimination.

Investigating feather corticosterone and fault bars along the length of domestic male turkey (Meleagris gallopavo) feathers

Fault bars are visible deformities in the feather structure potentially related to the stress response and may be an interesting trait that can reflect robustness. This study’s objective was to describe fault bars along the length of domestic turkey feathers and investigate whether fault bars are associated with feather corticosterone (FCORT). The same primary wing feather was evaluated from 75 male turkeys from three genetic lines. Feathers were cut into three (proximal, middle, and distal) sections to score fault bar presence, incidence, and severity. FCORT was measured for each feather section using ELISA. Linear mixed models were used to investigate differences in the fault bar presence, incidence, and severity between feather sections and genetic line, as well as investigate associations between the fault bar measures and FCORT. There was a significant increase in FCORT and fault bar incidence from proximal to distal feather sections ( P &lt; 0.0001). In the distal section only, sections with fault bars had significantly higher FCORT compared to sections without fault bars ( P = 0.0088). No associations were found between fault bars and FCORT in the other sections. Consequently, associating FCORT and fault bars using whole primary wing feathers may be challenging. Future work should reevaluate this relationship longitudinally to better understand fault bar development.

Occurrence and relevance of Mycoplasma sturni in free ranging barn swallows (Hirundo rustica) in Germany

In poultry industry, mycoplasmas cause large economic losses. The pathogenic significance of mycoplasmas varies widely between species. In birds where vocalization is crucial for reproductive success, mycoplasmas seem to be absent. Birds with high mycoplasma prevalence like birds of prey and storks do not rely on their vocalization for reproduction. Corvids with an intermediate prevalence use other strategies besides vocalization for mating. It is hypothesized that mycoplasma prevalence and vocalization used for reproduction is evolutionary related. Barn swallows have two traits relevant for mating: tail feather length and vocalization. An intermediate prevalence is expected. Little is known about mycoplasmas in barn swallows and their role as vector or reservoir for poultry pathogenic mycoplasmas. This study investigates the prevalence of mycoplasmas in barn swallows and their relevance for mycoplasma transmission to poultry. Choanal swabs from 188 healthy barn swallow nestlings of 59 different nests from ten different colonies on farms were examined for mycoplasmas by cultivation and genus-specific PCR including molecular biological differentiation of the species. In total, in 31 of 188 barn swallows (16.49%) and in 14 of the 59 nests (23.73%), mycoplasmas were detected. The occurrence of mycoplasmas per colony ranged from 0 to 50% independent of poultry being kept on the farm. In all positive samples, Mycoplasma sturni was identified. Mycoplasma sturni seems not to be an obligatory pathogen for barn swallows and occurs with an expected intermediate prevalence in them, so the results support the described hypothesis and underline a minor role of barn swallows for mycoplasma infection in poultry.

KARAKTERISASI BENIH DAN KEKERABATAN KULTIVAR PADI LOKAL PASANG SURUT DI KABUPATEN INDRAGIRI HILIR

Similarity analysis was carried out on the characteristics of local type tidal rice grain in Indragiri Hilit Regency in January-October 2015 in Indragiri Hilir Regency. This research aims to inventory, characterize and determine the relationship between each type of local tidal rice grain in Indragiri Hilir Regency. This research uses a qualitative-quantitative description method. The beginning of this research was to explore the types of rice grains in each village and sub-district of Indfagiri Hilir Regency, then they were characterized and analyzed using the agglomerative method by calculating the distance between relatives using hierarchical cluster average linkage (between gropus). The research results show that Indragiri Hilir Regency has 27 local tidal rice cultivars. These cultivars consist of 'Karya Kuning', 'Karanduku', 'Ramos', 'Pulut Putih', 'Pandan Wangi', 'Ordinary', 'Lembu Sawah Merah', 'Karya Merah', 'Pulut Hitam', ' Pariaman', 'Lembu Sawah', 'Karya Tinggi', 'Panama', 'Batang Tuaka', 'Ir Super', 'Batang Piaman', 'Maron', 'Merah Putih', 'Serang', 'Putri Malu', 'Super', 'Opium', 'White', 'Kuatik', 'Frog', 'Lentik Bamban', 'Sere'. Morphological characters that differentiate rice cultivars are grain characteristics (length, width, thickness, weight of 100 seeds, grain surface shape, grain surface color, sterile lemma length, grain tip color, grain tip tail feather color and grain tip tail feather length), character rice (length, width, thickness, ratio of length to width, and color of rice epidermis). Phenetic analysis using the Minitab Release version 17 program divided 27 local tidal rice cultivars into 9 clusters at a similarity level of 56.78%. Which consists of group 1, consisting of Karya Kuning, Karya Merah, Maron, Pulut Putih, Putih, Putri Malu, Merah Putih, Super; Group II consists of Karanduku, Opium and Lembu Sawah Merah; cluster III consists of Ramos, Batang Tuaka, Karya Tinggi, Serang and Pariaman, cluster IV consists of paddy cattle; Group V consists of Kuatik, Serai, Lentik Bamban, Kodok, Group VI consists of Ordinary and Batang Piaman and groups VII, VIII and IX respectively consist of Pandan Wangi, Super and Pulut Hitam.

Dermal FOXO3 activity in response to Wnt/β-catenin signaling is required for feather follicle development of goose embryos (Anser cygnoides)

Feather is an important economic trait of poultry, and growth and development state of feathers plays an important role in the economic value of poultry. Dermal fibroblasts are required for structural integrity of the skin and for feather follicle development. How FOXO3 affects feather follicle development as skin tissues change during goose embryo (Anser cygnoides) development and growth is not well understood. Here, we demonstrate that in vitro culture of single feathers and skin tissue results in changes in feather morphological structure by adding drugs to the culture medium that affect FOXO3 expression. We used feather follicles to show that during growth, the root location of feathers, the dermis layer, affects cell proliferation and apoptosis and regulates the expression of major genes in the Wingless-types/beta-catenin (Wnt/β-catenin) signaling pathway through the activity of FOXO3 in dermal fibroblasts. Feathers and dorsal skin tissues develop the correct structure, but feather length and width and feather follicle diameter change significantly (p < 0.05) without significant changes in feather follicle density (p > 0.05). Transfected dermal fibroblasts also showed that FOXO3 affected the formation and development of feather follicles in the embryonic stage by regulating the Wnt/β-catenin signaling pathway. Therefore, this study reveals the critical role of dermal fibroblast-FOXO3-induced Wnt/β-catenin signaling in promoting the formation and development of embryonic feather follicles.

Effect of Genotype and Holding Duration on Some Post-Hatch Traits of Day-Old Broiler Pure Line Chicks

In this study, it was aimed to investigate the effects of varying holding durations on some post-hatching characteristics of broiler pure line chicks with different selection backgrounds. Fifty d-old chicks from each of 3 dam (A1, A2, A3) and 1 sire (B1) ANADOLU-T broiler pure lines were used. Ten chicks of each genotype were treated with holding durations of 0, 12, 24, 36 and 48-h after hatching. At the end of each holding duration, individual chick weight (g), weight loss (g, %), chick length (mm), wing feather length (mm), rectal temperature (°C), yolk sac weight and percentage (g, %) and yolk-free body mass (g) were determined. Hatching egg weights were similar in A1 (60.9 g), A2 (60.9 g) and B1 (61.1 g) lines, but higher than A3 (59.2 g) (P

Maintaining the avian wing aerofoil: Relationships between the number of primary and secondary flight feathers and under‐lying skeletal size in birds

AbstractBird wings vary in size and morphology in terms of both size and number of feathers and the underlying skeletal anatomy. The number of primary remiges does not seem to vary much between bird species but, by contrast, the number of secondary remiges is reported to range between 6 and 40 depending on bird size. Given that the primaries are attached to the manus, and the secondaries are attached to the ulna, it was predicted that as bone lengths increased with increasing size of the bird, then feather count would increase. Data were collected for 268 species from 25 different orders, and phylogenetically controlled analysis explored the allometry between feather count and bone size. The number of primaries was typically 10 or 11 and did not vary with manus size. By contrast, the number of secondaries increased with ulna length, but only in some orders. For example, in Gruiformes, the number of secondary feathers increased concomitantly with ulna length but despite a two orders of magnitude range in body mass, almost all species in the Passeriformes had nine secondary remiges. It is unclear why, for instance, species with an ulna length of 70 mm can have between 9 and 24 secondaries depending on their order. This variation in secondary feather number can be added to variation in relative wing bone lengths, flight feather lengths, flight feather mechanical properties, and flight feather vane densities as another potential mechanism of adaptation to flight requirements. The apparent constraint of wingspan is scaling as approximately body mass1/3. Further research is needed to explore whether changes in secondary feather number relative to ulna length are accompanied by changes in feather vane width or the overlap of adjacent feathers and how this relates to wing aerodynamics.

Response of Sorghum Seeds to Soaking with Antioxidants (Glutathione) and Grown at Three Temperatures in Laboratory Conditions

The study aims to evaluate the pre-soaking of white corn seeds with different concentrations of glutathione under heat stress on some seed viability characteristics. The experiment was carried out in the laboratory of the Seed Examination and Certification Department. The Ministry of Agriculture, by soaking the seeds with four concentrations of glutathione (0, 50, 100, 150 mg L-1) for 12 hours and cultivating them under three temperatures (15, 25,35 °C) with the aim of knowing its effect on improving seed viability and germination strength. The experimental was carried out according to a completely randomized design (CRD) with four replicates. The results showed that the concentration of 150 mg L-1 was superior in germination speed, feather length, and peroxidase enzyme activity, as it gave these averages (79.32%, 9.57 cm, and 93.22 absorption units ml-1) respectively, the soaking treatment with a concentration of 100 mg L-1 excelled in the root length characteristic, and there was no significant difference between the concentrations in the dry weight of the seedling. The root, plumage and dry weight of the seedling gave values (81.50%, 14.62 cm and 13.30 cm 0.022 mg seedlin) respectively. The highest average temperature recorded in the activity of the biooxidase enzyme was (88.98 absorption units ml-1)

Identification of the Greater Spotted Eagle Clanga clanga, Lesser Spotted Eagle Clanga pomarina and interspecific hybrids using the morphology of shed flight feathers

ABSTRACT Capsule Shed feathers can be used for the field identification of the Greater Spotted Eagle Clanga clanga and Lesser Spotted Eagle Clanga pomarina, but identification of hybrids is problematic. Aims To provide an easy method for distinguishing the shed flight feathers of the Greater Spotted Eagle, Lesser Spotted Eagle, and their hybrids. Methods We examined seven morphological characteristics and developed multinomial logistic regression models to aid in identification of feathers. Results The most informative feature was the relative feather length. Barring improved the identification of tail feathers, secondaries, and proximal primaries. Feathers of Lesser Spotted Eagles were significantly shorter and more barred than those of Greater Spotted Eagles. Feathers of hybrids were also highly barred but had an intermediate length. The length from the tip to notch, width of the notch, and specific colouration patterns were also included in the best models for specific feather types. The combination of these characteristics resulted in identification accuracies of 89–97% for Lesser Spotted Eagle feathers and 80–100% for Greater Spotted Eagle feathers. However, all F1-hybrids were incorrectly identified as Greater Spotted or Lesser Spotted Eagles. Conclusion Shed feathers could have potential for the non-invasive field identification of spotted eagle species at nest sites. However, the identification of hybrids based on feathers is difficult due to substantial morphological variation and overlap with parent species.

Effect of seed soaking with Brassinolide on the vitality and vigor of Sorghum seed cultivars

A laboratory experiment was conducted at the Seed Technology Laboratory of the Department of Field Crops - College of Agriculture - the University of Anbar with the goal of To study the effect of seed soaking with the growth regulator brassinolide on the viability and vigor of seeds of cultivars sorghum, using a Complete Random Design (CRD). The first factor was soaking the seeds with the growth regulator brassinolide at concentrations of (200, 400, and 600) mg L-1 in addition to the control treatment (soaking with distilled water only) for the laboratory experiment with four repetitions. The second factor was three maize varieties White (Inqath, Rabah, and Lilo). The experiment results revealed that the stimulus treatment with brassinolide growth regulator at a concentration of 600 mg L-1 was significantly superior, with the highest averages for most of the studied traits, including germination speed (73.33 percent), standard laboratory germination rate (94.43 %), root length (16.08 cm), and feather length (15.36 cm). Besides, seedling strength (2968.2) and dry weight (0.0545 mg) in comparison to the control treatment (soaking in distilled water only), which had the lowest averages for the parameters evaluated. In terms of cultivars, the cultivar outperformed the rest of the cultivars in most of the measured attributes, with the highest standards. The cultivar was a Rabah in terms of germination speed (67.72 percent), germination percentage (87.67 %), stalk length (13.21 cm), gesture strength (2371.1), and dry weight (0.0513). Mg). The Inqath cultivar excelled in root length, recording the greatest average of (13.90 cm). The results revealed a significant effect of the interaction between the study parameters in most of the analyzed qualities. Based on the findings of this study. It can be concluded that stimulating the seeds with the growth regulator brassinolide generally resulted in an increase and improvement of all evaluated features, which reflected positively on seed viability and vigor. Keywords: Sorghum bicolor, growth regulator, seedling viability.

Revision of some mensural measurements, food preference, and haematological parameters in breeding pairs of blue rock pigeon, Columba livia sampled from punjab Pakistan

Abstract The present study describes the haematological profile, feeding preference, and comparison of morphometric characters of blue rock pigeon (Columba livia) breeding pairs. For this purpose, 25 pairs (25 samples per sex) were sampled through Mist nets from district Okara and Bahawalnagar, Punjab, Pakistan. Birds were then anaesthetized with a combination of ketamine HCL (10 mg/kg) and diazepam (0.2 mg/kg) and subjected to morphometric measurements. 5µL blood also was taken from the jugular vein of each anaesthetized bird for haematological analysis. Few pairs were also dissected to remove gastrointestinal tracts (GITs) for food preferences. Results revealed that there are no significant differences in the haematological parameters and feeding preference of breeding pairs of Columba livia. The gut analysis further revealed, the major portion of gut contents consisted of pea and corn in most of the pairs. Regarding the mensural measurements, significant differences were recorded in the body weight, length of the longest primary feather, and chest circumference, whereas the rest of the studied parameters remain nonsignificant between sexes. So, it is concluded that apart from 3 morphometric parameters (body weight, length of longest primary feather and chest circumference), both sexes are alike in term of morphometry, haematology and food preference.

Nonlinear model fitting analysis of feather growth and development curves in the embryonic stages of Jilin white geese (Anser cygnoides).

Poultry is subject to varying degrees of feather loss and feather pecking during production, which seriously affects the live appearance and carcass appearance of their commercial traits and greatly reduces the production profitability of the farming enterprise. It also has an impact on down production and quality in the case of geese. In this study, mathematical models (Logistic, Gompertz, and Von Bertalanffy) were used to assess feather growth and development during the embryonic period in Jilin white geese (Anser cygnoides) predicting the weight and length of feathers from the back, chest, and belly tracts at different embryonic ages, to determine which growth model more accurately described feather growth patterns. The result first showed that the primary feather follicles of the Jilin white goose developed at E14 and secondary feather follicles at E18; primary feather follicle density increased and then decreased, whereas secondary feather follicle density increased continuously and the primary and secondary feather follicles developed independently. Secondly, the embryonic feather growth followed a slow-fast-slow pattern, with feathers growing slowly from E12 to E18, quickly from E18 to E24, and then decreasing after E24 until just before emergence (E30). In addition, before E14, feathers were concentrated in the back tracts, and no feathers were found on the head, neck, chest, abdomen, or wings. By E22, the whole body of the embryo was covered with feathers, and the back feathers were the earliest and fastest to develop. Compared to the Gompertz and von Bertalanffy models, the logistic model fit (R2 = 0.997) was the highest, while the sum of residual squares (RSS = 25661.67), Akaike's information criterion (AIC = 77.600), Bayesian information criterion (BIC = 78.191), and mean square error (MSE = 2851.296) were the lowest. Therefore, the logistic model was more suitable for describing the changes in whole-body feather growth during the embryonic period in Jilin white geese. In conclusion, using the growth curve model to explain the relationship between feather growth and embryonic age in geese will potentially speed up the process of genetic improvement in Jilin white geese (A. cygnoides) and thus provide scientific support for molecular genetic breeding.

Genome-wide association analysis of the primary feather growth traits of duck: identification of potential Loci for growth regulation

The feather is an important epidermal appendage, plays an important role in the life activities of avian specie, and has important economic value. Revealing the molecular regulation mechanism of feather growth has a significant meaning in studying adaptive evolution, physiology, and mating of avian species and also provides a theoretical reference for poultry breeding. In this study, the genome-wide association analysis (GWAS) of 358 ducks was based on primary feather length phenotypic data (28-60 d), length growth rates (LGRs), and maturity scores (60 d) to explore the genetic basis affecting feather growth and maturation. The results showed that, among the primary feather 1 to 5 in ducks, the mean LGR of primary feather 2 was the fastest, with the longest length. The primary feathers in males grew and matured slightly faster than in females. The mean maturity scores of primary feather 10∼7 were higher than primary feather 1 to 3 in ducks. GWAS further showed 116 SNPs associated with feather length traits. In addition, 2 candidate regions (Chr1: 127,407,230-127,524,879 bp and Chr21: 182,061,707-183,616,298 bp) were associated with LGR, which contain total 13 candidate genes (The extremely significant SNPs were mainly located in 2 genes: Chr1: REPS2 and Chr21: PTPRT). Four candidate regions (Chr1: 29,113,036-28,675,018 bp, Chr2: 18,253,612-149,111,290 bp, Chr15: 6,489,774 to 12,138,221 bp and Chr21: 6,578,021-8,472,904 bp) were associated with feather maturity, which contain total 24 candidate genes (The extremely significant SNPs were mainly located in 4 genes: Chr1: IMMP2L, DOCK4 and DDX10, Chr2: LDLRAD4). In conclusion, sex factors influence feather growth and maturity, and the genetic basis of the growth /maturity trait between different feathers is similar. REPS2, PTPRT genes, and IMMP2L, DOCK4, DDX10, and LDLRAD4 are important candidate genes that influence feather growth and maturity, respectively.

Breeding Phenology and Nestling Morphology of Bald Eagles in the Upper Midwestern United States1

Abstract We report on egg-laying and hatching dates (n = 656), and morphological characteristics (n = 642) of nestling Bald Eagles (Haliaeetus leucocephalus) from six study areas in Minnesota and Wisconsin, USA, from 2006 to 2011, 2014, and 2015. Nestling age was estimated from length of the eighth primary feather using sex-specific equations from the literature. Egg-laying advanced from south to north beginning in late January and continuing through mid-April; hatching began in late February and ended in mid-May. Mean annual hatching dates were correlated with the average dates of ice break-up each spring at two ice-monitoring sites (n = 8 yr, r2 = 0.90). We found no significant long-term trend or shift in hatching dates over the 10 yr. Male and female nestlings overlapped in weight, footpad length, bill depth, and culmen and hallux claw chord length; however, by 35 d these features had diverged sufficiently to allow estimation of the sex of nestlings due to the larger size of females (P &amp;lt; 0.05 all contrasts). Our models suggest that most of the nestling traits we measured continued to grow beyond the 70 d for which we had measurements, except for footpad, which reached predicted full size by about 46 d after hatching. Footpad length and bill depth were important traits for determining the sex of nestlings ≥35 d old. We provide a classification tree that uses footpad length and bill depth to estimate the sex of nestlings. Overall accuracy of this classification tree was 91%. Individuals with footpad length ≥132 mm and bill depth ≥29 mm (46% of our sample) had a 0.95 probability of being female and individuals with footpad length &amp;lt;132 mm and bill depth &amp;lt;30 mm (41% of our sample) had a 0.92 probability of being male, making our classification tree unbiased and robust for assigning sex for most nestlings ≥35 d old.

Morphometric measurements, productive and reproductive performance of Deshi black and Deshi white duck

At the Central Duck Breeding Farm Hajiganj in Narayanganj, Bangladesh, morphometrics, productive, and reproductive performances of Deshi black and Deshi white ducks were measured under intensive conditions. Body length, head length, bill length, neck length, feather length, and shank length of mature male and female Deshi black and Deshi white ducks measured 59.56 ± 0.87 cm and 61.87 ± 0.48 cm, 2.25 ± 0.12 cm, and 3.4 ± 0.06 cm, 5.86 ± 0.12 cm, and 6.23 ± 0.06 cm, 19.21 ± 0.47 cm and 21.08 ± 0.26 cm, 21.85 ± 0.53 cm and 26.71 ± 0.29 cm, 9.93 ± 0.29 cm and 10.81 ± 0.16 cm, respectively. Morphometric features were significantly (p < 0.01, p < 0.05) higher in females than males. But no significant differences (p > 0.05) were detected between the two types of ducks except for the body, head, and feather length (p < 0.01, p < 0.05). At a day old, 4th week, 8th week, and 12th week of age, the body weights (LSMean ± SE) of male and female Deshi black and Deshi white ducks were 42.65 ± 0.35 gm and 43.40 ± 0.35 gm, 318.00 ± 9.13 gm and 319.04 ± 9.13 gm, 835.85 ± 8.94 gm and 794.20 ± 8.94 gm, 1345.80 ± 2.67 gm and 1347.90 ± 2.67 gm, respectively (gm = gram). Females were substantially heavier than males at 8 weeks of age (p < 0.01), but there was no significant difference in body weights between the two types of ducks (p > 0.05) until the 12th week of age (p < 0.01). Deshi black and Deshi white ducks reached sexual maturity at 136.0 ± 0.52 and 139.0 ± 0.52 days, respectively, and had 67.62 ± 0.83% and 63.18 ± 0.83%, 63.63 ± 0.56%, and 59.42 ± 0.56% fertility. Deshi black ducks had a substantially higher age at sexual maturity, fertility, and hatchability percentage (%) than Deshi white ducks (p < 0.01). For Deshi black and Deshi white, the egg weight, female weight at 1st lay, and egg weight at 1st lay were 66.69 ± 0.49 gm and 66.78 ± 0.49 gm, 1439.55 ± 6.98 gm and 1422.0 ± 6.98 gm, 48.90 ± 0.18 gm and 47.12 ± 0.18 gm, respectively. Deshi black duck egg weight was considerably (p < 0.01) higher than Deshi white duck egg weight at first lay. Deshi black and Deshi white ducks produced 214.65 and 211.402.65 eggs per year, respectively (p > 0.05). The study's findings gave some baseline information on Bangladesh's Deshi black and Deshi white ducks, which could benefit conservation and future enhancement efforts.

Effects of DL and L-Methionine on Growth Rate, Feather Growth, and Hematological Parameters of Tetra-SL Layers from 1-28 Days of Age.

Simple SummaryMethionine is the first limiting amino acid and plays an important role in the growth and health status of chicks. Animal health status was easily detected by examining the hematological parameters. This study aimed to investigate the influence of methionine sources (L-methionine and DL-Methionine) at different supplementation levels (10% deficit, 100% and 10% surplus of the recommended) on growth performance and health status of chicks. The results of the feeding trial found no differences in the chicks’ growth performance and feather growth on neither methionine sources nor methionine levels. However, most of the hematology parameters were affected by the methionine sources and/or methionine levels, as well as their interaction being significant in some cases. Therefore, this trial showed that varying methionine by ±10% of the requirements does not adversely affect growth performance and feather growth.The study was carried out to determine whether sources or levels of methionine (Met) affect the health status of Tetra-SL (TSL) chicks by examining growth performance, feather growth, and hematological parameters. A total of ninety-six (96) day-old (44.2 ± 0.18 g lw) TSL chicks were randomly allotted to six treatment groups (three levels for each DL and L-Met source) with four replicates of four chicks each. Chicks were fed ad libitum diets supplemented with 90, 100, and 110% of methionine requirements for four weeks after hatch. The parameters examined are bodyweight (BW), average daily gain (ADG), feather length (FL), and hematological parameters, including: red blood cell (RBC) count, hemoglobin (Hb) concentration in the blood, hematocrit (Ht; %), number of white blood cells (WBC), platelet count, mean corpuscular volume of red blood cells (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), lymphocyte (LYM), mid-range (MID), and granulocyte (GRAN). There was no significant effect of Met sources and levels on BW, ADG, and FL of TSL chicks for the first four weeks of rearing. The RBC, Hb, Ht, WBC, LYM, MID, and GRAN values of TSL chicks were statistically influenced by dietary Met sources and Met levels (p < 0.05). Among the treatment groups, the number of white blood cells (WBC) on 90% DL–Met was the lowest. WBC, RBC, Hb, and Ht were higher from chicks that received 100% DL-Met than all other levels, regardless of the Met sources. The MCV, MCH, and MCHC values were not affected by either Met source or levels or their interactions. Met source and level interactively affected the Ht, WBC, LYM %, and GRAN values of TSL chicks (p < 0.05). The platelet number was affected by Met source only (p < 0.05) with chicks receiving L-Met source having more than twofold higher platelet values than DL-Met source. In conclusion, varying Met levels by ±10% of the requirement does not adversely affect the growth performance, feather growth, and hematological parameters of TSL chicks reared for up to four weeks of age. DL-Met increased the body weight and improved the white blood cells, red blood cells, and hematocrit at 28 days after hatch. DL-Met showed similar biological efficacy as L-Met for body weight and feather growth but not for the hematological parameters.