Genomic Regions Related to White/Black Tail Feather Color in Dwarf Chickens Identified Using a Genome-Wide Association Study

Although the genetic foundation of chicken body feather color has been extensively explored, that of tail feather color remains poorly understood. In the present study, we used a synthetic chicken dwarf line (DW), derived from hybrids bred between a black tail chicken breed, Rhode Island Red (RIR), and a white tail breed, dwarf layer (DL), to investigate the genetic rules associated white/black tail color. Even though the body feathers are predominantly red, the DW line still comprises individuals with black or white tails after more than 10 generations of self-crossing and selection for the body feather color. We first performed four crosses using the DW chickens, including black-tailed males to females, reciprocal crosses between the black and white, and white males to females to elucidate the inheritance pattern of the white/black tail. We also performed a genome-wide association (GWA) analysis to determine the candidate genomic regions underlying the tail feather color using black tail chickens from the RIR and DW lines and white individuals from the DW line. In the crossing experiment, we found that (i) the white/black tail feather color is independent of body feather color; (ii) the phenotype is a simple autosomal trait; and (iii) the white is dominant to the black in the DW line. The GWA results showed that seven single-nucleotide polymorphisms (SNPs) on chromosome 24 were significantly correlated with tail feather color. The significant region (3.97–4.26 Mb) comprises nine known genes (NECTIN1, THY1, gga-mir-1466, USP2, C1QTNF5, RNF26, MCAM, CBL, and CCDC153) and five anonymous genes. This study revealed that the white/black tail feather trait is autosome-linked in DW chickens. Fourteen genes were found in the significant ~0.29 Mb genomic region, and some, especially MCAM, are suggested to play critical roles in the determination of white/black tail feather color. Our research is the first study on the genetics underlying tail feather color and could help further the understanding of feather pigmentation in chickens.

Effects of Outdoor Stocking Density on Growth, Feather Damage and Behavior of Slow-Growing Free-Range Broilers

Access to pasture is a main benefit of free-range broiler housing systems, yet the level of outdoor stocking density on broiler animal welfare remains unsettled. The growth, feather damage, pasture ranging and behaviors were assessed for 150 mixed-sex, slow-growing Freedom Rangers from 5 to 11 weeks of age of with free access to either a high outdoor stocking density pasture (0.5 m2 per bird) or a low outdoor stocking density pasture (2.5 m2 per bird). The probability (mean, 95% CI) of tail feather damage was greater for the high-density (23.1%, 16.3 to 31.7%) compared to the low-density group (11.9%, 7.1 to 19.3%). The percent of observations resulting in sunbathing and aggressive attacks (i.e., pecking and fighting behaviors) were greater for the high-density (1.0%, 0.6 to 1.8% and 0.5%, 0.2 to 1.3%, respectively) compared to the low-density group (0.3%, 0.1 to 0.7% and 0.1%, 0.0 to 0.4%, respectively). Furthermore, an interaction between treatment and age indicated that birds in the high-density group displayed greater stretching (during weeks 7 to 10) and panting (during weeks 6 and 9). Results of this study suggest that additional outdoor pasture space may be positively associated with broiler welfare.

BENTUK VISUAL KOSTUM TARI MERAK JAWA BARAT KARYA IRAWATI DURBAN ARDJO

Tari Merak Jawa Barat, merupakan jenis tarian tontonan (pertunjukan). Tari Merak pertama kali diciptakan oleh Rd. Tjetje Somantri pada tahun 1955. Kemudian pada tahun 1965, tari Merak dikemas kembali oleh Irawati Durban Ardjo, yang bertujuan untuk dipertunjukkan pada misi kesenian Soekarno. Tari Merak yang sering kita jumpai saat ini merupakan Tari Merak karya Irawati Durban Ardjo.Tarian ini mempresentasikan keindahan yang dimiliki oleh burung merak pada saat burung merak jantan melebarkan ekornya. Kebanyakan masyarakat Indonesia salah berasumsi jika tarian ini bercerita tentang kehidupan burung merak betina, sedangkan sang jantanlah yang memamerkan keindahan bulu ekornya. Sang jantan melakukan gerak-gerik yang tampak seperti tarian gemulai untuk menunjukkan pesona dirinya, sehingga sang betina terpesona dan bersedia kawin dengannya. Gerakan itulah yang mengekspresikan dibuatnya Tari Merak. Untuk mendukung keindahan tari, maka dibuat bentuk visual Merak pada kostum Tari Merak yang telah diinovasikan oleh Irawati. Irawati mengonsepnya melalui ide-ide kreatif dan mengindahkan esensi burung merak pada bentuk visual. Beberapa bagian kostum tari Merak Irawati, yaitu siger (mahkota), susumping, giwang (anting), kelat bahu, garuda mungkur, gelang tangan, kemben, ekor, Ikat pinggang, kacih, selendang, dan sinjang. Kostum yang memiliki banyak unsur estetika seperti garis (lurus, lengkung, bergelombang), bentuk (lingkaran, setengah lingkaran, persegi panjang, ekor merak, dan penyederhanaan burung merak), ornamen (ragam hias binatang, ragam hias tumbuhan, geometris, ulir). Beberapa motif yang digunakan yaitu motif ekor, bulu, ataupun keseluruhan bentuk burung merak. ABSTRACT Peacock Dance is a type of spectacle dance (performance). The Peacock Dance was first created by Rd. Tjetje Somantri in 1955. Then in 1965, the Merak dance was repackaged by Irawati Durban Ardjo, which aimed to be performed on Soekarno's art mission. The Peacock Dance that we often encounter at the moment is the Peacock Dance by Irawati Durban Ardjo. This dance presents the beauty of peacocks. The peacock is the inspiration for the creation of the Peacock dance and its beauty is found when the male peacock widens its tail. Most Indonesian people wrongly assume that this dance tells the story of the life of a female peacock, while the male exhibits the beauty of its tail feathers. The male performs movements that look like graceful dances to show his charms so that the female is fascinated and willing to marry him. That movement expresses the Peacock Dance. With the visual form of the Peacock Dance costume that has been innovated by Irawati. Irawati conceptualized it through creative ideas and heeded the essence of the peacock in visual form. Some parts of the Merraw Irawati dance costume, namely siger (crown), susumping, ear studs (earrings), kelat shoulders, garuda mungkur, wristbands, kemben, tail, belt, belts, shawls, and sinjang. Costumes that have many aesthetic elements such as lines (straight, curved, wavy), shapes (circles, semicircles, rectangles, peacock tails, and simplifications of peacocks), ornaments (various animal decoration, plant decoration, geometric, threaded). Some of the motifs used are the tail, feather, or overall shape motif.

Differential effects of early growth conditions on colour-producing nanostructures revealed through small angle X-ray scattering and electron microscopy

ABSTRACTThe costs associated with the production and maintenance of colour patches is thought to maintain their honesty. Although considerable research on sexual selection has focused on structurally coloured plumage ornaments, the proximate mechanisms of their potential condition dependence, and thus their honesty, is rarely addressed, particularly in an experimental context. Blue tit (Cyanistes caeruleus) nestlings have ultraviolet (UV)–blue structurally coloured tail feathers, providing a unique opportunity for investigation of the causes of variation in their colour. Here, we examined the influence of early growing conditions on the reflectance and structural properties of UV–blue-coloured tail feathers of blue tit nestlings. We applied a two-stage brood size manipulation to determine which stage of development more strongly impacts the quality of tail feather colouration and microstructure. We used small-angle X-ray scattering (SAXS) and electron microscopy to characterise the nanoscale and microscale structure of tail feather barbs. Nestlings from the broods enlarged at a later stage of growth showed a sex-specific rectrix development delay, with males being more sensitive to this manipulation. Contrary to predictions, treatment affected neither the quality of the barbs’ nanostructures nor the brightness and UV chroma of feathers. However, at the microscale, barbs’ keratin characteristics were impaired in late-enlarged broods. Our results suggest that nanostructure quality, which determines the UV–blue colour in tail feathers, is not sensitive to early rearing conditions. Furthermore, availability of resources during feather growth seems to impact the quality of feather microstructure more than body condition, which is likely to be determined at an earlier stage of nestling growth.

Biophotonics of diversely coloured peacock tail feathers

The diversity of peacock tail feather colours is explained by multilayer modelling.

A mid-Cretaceous enantiornithine foot and tail feather preserved in Burmese amber

Since the first skeletal remains of avians preserved in amber were described in 2016, new avian remains trapped in Cretaceous-age Burmese amber continue to be uncovered, revealing a diversity of skeletal and feather morphologies observed nowhere else in the Mesozoic fossil record. Here we describe a foot with digital proportions unlike any previously described enantiornithine or Mesozoic bird. No bones are preserved in the new specimen but the outline of the foot is recorded in a detailed skin surface, which is surrounded by feather inclusions including a partial rachis-dominated feather. Pedal proportions and plumage support identification as an enantiornithine, but unlike previous discoveries the toes are stout with transversely elongated digital pads, and the outer toe appears strongly thickened relative to the inner two digits. The new specimen increases the known diversity and morphological disparity among the Enantiornithes, hinting at a wider range of habitats and behaviours. It also suggests that the Burmese amber avifauna was distinct from other Mesozoic assemblages, with amber entrapment including representatives from unusual small forms.