| [preliminary examinations on the effects of the breed characteristic feature "feather crest" on skull and brain anatomy of domestic ducks (anas platyrhynchos f. dom.)]. | as mentioned in older sources, the crested breed of the domestic duck is described as variety with high pre- and postnatal mortalities, malformations in skull and brain anatomy, and several central nervous deficiencies in affected birds. therefore this breed is to be called defective and abnormal in the sense of section 11b of the german protection of animals legislation. poultry fanciers reject these findings as incorrect, but accurate scientific examinations that bear out this allegation are n ... | 1998 | 9646407 |
| osteological investigations of the incidence of cranial alterations in domestic ducks (anas platyrhynchos f. dom.) with feather crests. | the feather crest of the domestic duck (anas platyrhynchos f. dom.) represents a peculiar mutation of the integument of the head, which has been known since the 17th century. in literature this is described as a variety with malformations in skull and brain anatomy in which various central nervous deficiencies in affected birds are possible. our examinations demonstrated several conspicuous anatomical alterations in the skulls of domestic ducks with feather crests. osteophytes of different size ... | 2001 | 11206986 |
| magnetic resonance imaging of intracranial tissue accumulations in domestic ducks (anas platyrhynchos f. dom.) with feather crests. | the crested breed of domestic duck (anas platyrhynchos f. dom.) has been described as a variety which has high pre- and postnatal mortalities, malformations in skull and brain anatomy, and several central nervous deficiencies. in addition, intracranial tissue accumulations have been diagnosed in purebred crested ducks. the incidence, heredity and inheritance of these accumulations as well as their pathogenesis are still generally unknown. the aims of this study were to examine the head of creste ... | 2001 | 11405270 |
| brain alterations in crested versus non-crested breeds of domestic ducks (anas platyrhynchos f.d.). | a comparison of brain size and brain composition was made between two uncrested duck breeds and crested ducks (cr) and between cr individuals that do possess crests and those that do not have the crest. domestic ducks of the breed cr have allometrically larger brains than uncrested duck breeds. the crest inserts on a cushion of fat and connective tissue that is partly nourished by brain vessels via small holes in the skull. through these holes, fat tissue may invade the brain cavity. because the ... | 2001 | 11558908 |
| ataxia and disequilibrium in domestic ducks (anas platyrhynchos f. dom.) with intracranial lipomas. | four birds in a flock of 125 purebred crested ducks (anas platyrhynchos f. dom.) had cerebellar signs of unknown etiology. they had radiographically evident perforations of various sizes in the parieto-occipital calvaria. gross necropsy of euthanatized ducks revealed yellow intracranial masses in the brain of each. histologically, these masses were intracranial lipomas consisting of univacuolated fatty tissue separated into lobules by strands of connective tissue. the masses had caused serious d ... | 2002 | 12014506 |
| [implementation of paragraph 11b of the german animal welfare act on the basis of the so-called "quality breeding" report]. | enforcement of paragraph 11b of the german animal welfare act is a responsibility of breeders and their organisations as well as executive local authorities. the report on defective breeds of the federal ministry of agriculture describes numerous breeding traits which are in conflict with animal welfare and gives valuable information for fancy or pet breeding. yet a selection has to be made for taking legal actions, following specific criteria. with four examples different cases are presented, e ... | 2004 | 15195961 |
| brain size, brain composition and intracranial fat bodies in a population of free-living crested ducks ('hochbrutflugenten'). | (1) brain sizes and brain structure volumes of crested specimens from a population of 'hochbrutflugenten' ducks (hbtcr), living under seminatural conditions, were compared with those of other duck breeds, among them the breed 'landente' with the same morphological trait, the crest (lecr). (2) brains of both hbtcr and lecr were larger than expected from an allometric comparison with uncrested breeds. (3) fat bodies invading the skull were observed in both breeds. (4) in lecr they could be volumin ... | 2004 | 15623210 |
| [intracranial fat bodies and their potential effect on brain composition and behaviour in domestic ducks with feather crests (3 case studies)]. | intracranial fat tissue was found in the brains of three crested ducks. the three ducks differed in the size of their crest and in the volume and the location of the fat body within their brains. the duck with the large crest showed a fat body which counts for 19 % of its brain volume. due to this fat accumulation, brain structures, mainly the cerebellum, were moved laterally. this duck had serious problems in motor coordination. fat body of the second duck with a middle sized crest was situated ... | 2006 | 16475552 |
| motor incoordination, intracranial fat bodies, and breeding strategy in crested ducks (anas platyrhynchos f.d.). | some crested ducks (cr) are burdened with an intracranial fat body that, depending on the size and location, may lead to varying degrees of motor incoordination. a behavioral test is proposed that helps to identify those cr individuals bearing the problematical fat body. the test consists of putting the ducks on their backs and measuring the time required to right themselves. this was repeated 13 times per animal, and means were calculated. the minimum time required was 0.5 s, and the maximum wa ... | 2007 | 17704370 |
| unusual brain composition in crested ducks (anas platyrhynchos f.d.)--including its effect on behavior and genetic transmission. | crested ducks (cr) occasionally show intracranial fat bodies. additionally, behavioral abnormalities such as motor incoordination can be observed. here, it is shown that a behavioral test helps to identify cr that have a problematical fat body. the ducks were put on their backs, and the time required for them to stand up was measured. ten cr exhibited suboptimal motor coordination. the appropriateness of this test has been proved in a special breeding program. to investigate the influence of fat ... | 2008 | 18498950 |
| the use of conventional radiography and computer-assisted tomography as instruments for demonstration of gross pathological lesions in the cranium and cerebrum in the crested breed of the domestic duck (anas platyrhynchos f.dom.). | according to literature reports, the crested breed of the domestic duck (anas platyrhynchos f. dom.) is described as a variety with high pre- and post-natal mortalities, malformations in skull and brain anatomy, and various central nervous deficiencies in affected birds. a detailed examination as to the cause and pathogenesis of these neurologic disorders has not yet been conducted, nor has an explanation concerning the inheritance of the feather crest been found. by using two non-invasive radio ... | 2000 | 19184795 |
| multilocus coalescent analysis of haemoglobin differentiation between low- and high-altitude populations of crested ducks (lophonetta specularioides). | hypoxia is a key factor determining survival, and haemoglobins are targets of selection in species native to high-altitude regions. we studied population genetic structure and evaluated evidence for local adaptation in the crested duck (lophonetta specularioides). differentiation, gene flow and time since divergence between highland and lowland populations were assessed for three haemoglobin genes (α(a) , α(d) , β(a) ) and compared to seven reference loci (six autosomal introns and mtdna). four ... | 2011 | 22151704 |
| stomach nematodes of three sympatric species of anatid birds off the coast of patagonia. | the present study focuses on the nematode community in the stomachs of three sympatric anatid bird species from the central patagonian coast, argentina. the bird species include the chubut steamer duck, tachyeres leucocephalus, the crested duck, lophonetta specularioides, and the black-necked swan, cygnus melancoryphus. up to 138 nematodes representing five species were recovered from 10 of the 13 ducks examined, with an overall prevalence of 77% and a mean intensity of 13.8. nematodes isolated ... | 2016 | 26522056 |
| the differentiation of preadipocytes and gene expression related to adipogenesis in ducks (anas platyrhynchos). | meat quality is closely related to adipose tissues in ducks, and adipogenesis is controlled by a complex network of transcription factors tightly acting at different stages of differentiation especially in ducks. the aim of this study was to establish the preadipocyte in vitro culture system and understand the biological characteristics of expansion of duck adipocyte tissue at the cellular and molecular level. we isolated pre-adipocytes from the subcutaneous fat of three breeds of duck and diffe ... | 2018 | 29771917 |
| divergent respiratory and cardiovascular responses to hypoxia in bar-headed geese and andean birds. | many high-altitude vertebrates have evolved increased capacities in their oxygen transport cascade (ventilation, pulmonary diffusion, circulation and tissue diffusion), enhancing oxygen transfer from the atmosphere to mitochondria. however, the extent of interspecies variation in the control processes that dictate hypoxia responses remains largely unknown. we compared the metabolic, cardiovascular and respiratory responses to progressive decreases in inspired oxygen levels of bar-headed geese (a ... | 2017 | 29141880 |
| embryonic morphology observation and hoxc8 gene expression in crest cushions of chinese crested duck. | the chinese crested duck (fengtou duck) reappeared in china recently. along with white feathers and a black bill and feet, the fengtou duck has a high feather crest. this breed can be used for ornamental purposes or as a model organism; however, little is known about the genetic basis and development of its distinct morphological features. in this study, we observed the skull and feather crest of fengtou duck in the embryonic stages. as a result, the protuberances of the head integument could be ... | 2019 | 30529099 |
| whole genome re-sequencing of crested traits and expression analysis of key candidate genes in duck. | the crested duck was a duck breed which features a topknot of feathers on the back of their head. in order to explain the reason of crest, we anatomy the head of some crested ducks. the anatomical structures showed that there was a fat body in the head and a hole in the skull. to determine the reason for the formation of the crest, we used whole genome re-sequencing to detect snps and indels in three crested duck and three normal crested duck (without crest). there were 785,202 unique snps and 1 ... | 2020 | 31838250 |
| notocotylus primulus n. sp. (trematoda: notocotylidae) from the crested duck lophonetta specularioides (aves, anatidae) from patagonian coast, southwestern atlantic ocean. | species in the genus notocotylus (trematoda, notocotylidae) are cosmopolitan parasites of mainly aquatic birds and, to a lesser extent, mammals. in this paper we describe notocotylus primulus n. sp. parasitizing the crested duck, lophonetta specularioides, from the patagonian coast, southwestern atlantic ocean, based on morphological and molecular data. the new species could be distinguished from its congeners by the combination of several features; among them, the position of the genital pore t ... | 2020 | 31513918 |
| negative regulation of the rlr-mediated ifn signaling pathway by duck ubiquitin-specific protease 18 (usp18). | ubiquitin-specific protease 18 (usp18) plays an important role in regulating type i interferon (ifn) signaling in innate immunity, and has a crucial impact on the ifn therapeutic effect. although significant progress has been made in elucidating usp18 function in mammals, the role of usp18 in ducks (duusp18) remains poorly understood. in this study, we cloned the usp18 gene from white crested ducks by reverse transcription polymerase chain reaction (rt-pcr) and rapid amplification of complementa ... | 2019 | 30256391 |
| identification of differentially expressed micrornas during preadipocyte differentiation in chinese crested duck. | micrornas (mirnas) are considered key players in the regulation of a broad range of biological processes. specifically, mirnas have been reported to play an important role in the process of adipogenesis. in this study, we constructed a model of adipogenesis by isolating preadipocytes (wcc) derived from adipose tissue and preadipocytes after 72 h differentiation (wct) in vitro. deep sequencing of mirnas expressed in wct and wcc cells was conducted; we identified 105 differentially expressed mirna ... | 2018 | 29604463 |