Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Feathers”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2006

The feathering gene is linked to degranulation and oxidative burst not cytokine/chemokine mRNA expression levels or Salmonella enteritidis organ invasion in broilers.

In the past, we showed differences in heterophil function between parental broilers (A [fast feathering] > B [slow feathering]) and their F1 reciprocal crosses (D [fast feathering] > C [slow feathering]). In the present study, we evaluated the linkage of the feathering gene to heterophil function, pro-inflammatory cytokine/chemokine mRNA expression levels, and resistance to Salmonella enteritidis organ invasion. Heterophils were isolated from 2-day-old chickens (C and D) separated into males and females - slow males and females (SM and SF), and fast males and females (FM and FF). Heterophil functions of degranulation and oxidative burst were measured. Heterophils from FF chickens (183+/-8.9) released more (P < 0.05) beta-d-glucuronidase (microM) than heterophils from SF chickens (149+/-3.7); FF heterophils (4.6 x 10(4)) generated a significantly (P < 0.05) greater oxidative burst (mean relative fluorescent units) compared with SF heterophils (4.2 x 10(4)). Interleukin-6, CXCLi2, and interferon-alpha mRNA expression levels were quantitated by real-time quantitative reverse transcriptase-polymerase chain reaction. No differences were observed between SM and FM or between SF and FF heterophils. Finally, 1-day-old chickens were administered S. enteritidis and liver/spleen organ invasion was quantitated. No differences were observed between the number of S. enteritidis-positive FF and SF chickens, but FM were significantly (P < 0.05) more resistant to S. enteritidis organ invasion than SM chickens. The data indicate degranulation and oxidative burst were linked with the feathering gene; however, interleukin-6, CXCLi2, and interferon-alpha mRNA expression levels were not. Furthermore, susceptibility to in vitro S. enteritidis organ invasion was not linked to the feathering gene.

Aging↗
PubMedDate not supplied

Abnormal feathers of the micromelic syndrome in White pekin ducks.

In an effort to provide further information concerning the pleiotropic effects of the gene mutation responsible for micromelia in White Pekin ducklings, a histological examination was made oq the abnormal feathers associated with the mutation. Abnormalities found in mutant feathers included decreased overall size, absence of prelumulae and prefiloplumulae feathers, an abnoramlly small rhachis with a disproportionally small medulla, thickening of the feather-sheath, and increased abundance of pulp cells. Embryos having the most abnormally developed feathers and the thickest periderm and feather-sheaths. The nature of many of the abnormalities found in mutant feathers suggests a common source in defective embryonic mesoderm.

Animals↗
PubMed1997

Feather retention force in broilers ante-, peri-, and post-mortem as influenced by carcass orientation, angle of extraction, and slaughter method.

Stunning and slaughter trials were conducted to evaluate the influence of carcass orientation (inverted or supine), angle of feather extraction (parallel or perpendicular to the carcass surface), and slaughter method (exsanguination without or with spinal cord transection) on feather retention force (FRF) in commercial broilers sampled ante-, peri-, and post-mortem. The pectoral, sternal, and femoral feather tracts were sampled before and after stunning contralaterally, with a maximum indicating force gauge, from broilers suspended on a shackle (inverted) or laying on a table (supine). For all trials and sample periods FRF was consistently greater in the femoral area (547 to 679 g) than in the pectoral area (273 to 391 g), with the sternal feather tract requiring the least force at 246 to 343 g. Feathers extracted parallel to the carcass resulted in consistently greater FRF (9 to 29%) than feathers extracted at a perpendicular angle, at all sample periods. Broilers suspended on shackles ante- and peri-mortem had higher FRF values (5 to 30%) than those restrained in shackles in a supine position on a table. Other parameters resulted in minor and inconsistent alterations in FRF. Electrical stunning, when not followed by bleeding, resulted in small reductions in FRF (up to 7%). Bleeding after stunning without or with spinal cord transection resulted in variable peri-mortem FRF changes (+7 to -11% and +11 to -11%, respectively). Only in the pectoral feather tract was there a significant increase (5 to 6%) in FRF as broilers went from the ante- to peri-mortem state. At 2 and 6 min after stunning and initiation of exsanguination, post-mortem FRF was unaffected by carcass orientation for the pectoral and femoral tracts.

Abattoirs↗
PubMed2003

Bacterial recovery from breast skin of genetically feathered and featherless broiler carcasses immediately following scalding and picking.

Genetically feathered and featherless sibling broilers selected for matched BW were killed, scalded, and defeathered to determine the consequences of feathers and empty feather follicles on the recovery of bacteria from carcass breast skin. In trial 1, the vents of all carcasses were plugged and sutured before scalding to prevent the expulsion of cloacal contents during picking. In trial 2, half of the carcasses had their vents plugged and sutured. Immediately after defeathering, breast skin was aseptically removed, and bacteria associated with it were enumerated. In trial 1, the levels of bacteria recovered did not differ between feathered and featherless carcasses: Campylobacter log10 1.4 cfu/mL of rinse, coliform log10 1.8, Escherichia coli log10 1.6, and total aerobic bacteria log10 3.1. In trial 2, the carcasses that had vents plugged and sutured had lower levels of all four types of bacteria (differences of Campylobacter log10 0.7 cfu/mL, coliform log10 1.8, E. coli log10 1.7, and total aerobic bacteria log10 0.5) than those carcasses with open vents. The lower levels of bacteria recovered from carcasses with the vents plugged and sutured during picking enabled detection of small but significant differences between feathered and featherless carcasses. The level of coliform and E. coli recovered was slightly higher by log10 0.7 cfu for feathered carcasses, but featherless carcasses had marginally higher levels of total aerobic bacteria by log10 0.4 cfu. Feathered and featherless carcasses with open vents during picking did not differ in the levels of recovery of coliform, E. coli, and total aerobic bacteria from breast skin.

Animals↗
PubMed2004

Effects of nutrient density on growth and carcass traits in fast- and slow-feathering female turkeys.

Chickens have been sexed based on feather development at hatching for many years, but the slow-feathering gene has only recently been incorporated into a commercial line of turkeys. Female turkeys of a fast- and a slow-feathering strain were compared with regard to BW, gain, and carcass composition to 29 wk of age. A total of 432 fast-feathering (FF) and 432 slow-feathering (SF) poults were reared to 198 d on a control (CON) or a high-energy, high-protein (HIGH) diet. Data concerning BW and carcass characteristics (thoracic circumference and width, shank, keel, breast muscle, fat pad, and liver), feather scores, and breast muscle morphology were assessed over the course of the trial. Strain did not affect BW of the CON-fed birds until after 112 d, when FF birds were 3.1% heavier than SF birds. From 11 to 112 d, feeding the HIGH diet increased BW of SF birds significantly compared with birds fed the CON diet. From 170 to 198 d, FF birds were approximately 0.8 kg heavier than SF birds. At 42 and 84 d in FF birds, and at 84 d in SF birds, increased diet density increased measures of frame size and decreased liver weight. Breast muscle weight, area, and thickness were greater in SF than in FF birds at 42 and 84 d. Increased nutrient density increased feather score in SF birds at 32 (9.8%) and 56 d (7.1%).

Animal Feed↗
PubMed2005

Bacteria recovery from genetically feathered and featherless broiler carcasses after immersion chilling.

Feathered and featherless (scaleless) sibling broilers were reared and processed together to evaluate the influence of feathers and feather follicles on carcass bacteria recovery after chilling. In each experiment, broilers were inoculated 1 wk prior to processing by oral gavage with a suspension of salmonellae or Campylobacter at 106 cells/mL. Broilers were stunned and bled, and carcasses were single-tank or triple-tank scalded, defeathered, eviscerated, and washed. Carcasses were chilled for 45 min in ice and water immersion chillers with or without 20 mg of chlorine/L added. Postchill carcass rinsates were evaluated for Escherichia coli, coliforms, total aerobes, and salmonellae or Campylobacter. Following processing and immersion chilling, genetically featherless carcasses had slightly higher counts (by log10 0.35 cfu/100 mL of carcass rinsate) for E. coli, coliforms, and total aerobes than feathered carcasses. However, there were no significant differences in the prevalence of salmonellae (25%) or Campylobacter (93%) between feathered and featherless carcasses. Recovery of E. coli, coliforms, and total aerobic bacteria were lower for carcasses that were single-tank scalded, and following enrichment, salmonellae were recovered from fewer carcasses subjected to the single-tank (71%) than triple-tank (86%) scalding. Addition of chlorine to chiller water significantly decreased carcass bacteria recovery (by log10 0.43 cfu/100 mL of carcass rinsate) for E. coli, coliforms, total aerobes, and Campylobacter but did not affect salmonellae recovery. The presence of feathers and feather follicles during processing and immersion chilling appears to have minimal influence on the recovery of salmonellae or Campylobacter from carcasses sampled after immersion chilling.

Animals↗
PubMed2005

Formation of spacing pattern and morphogenesis of chick feather buds is regulated by cytoskeletal structures.

Chick feather buds develop sequentially in a hexagonal array. Each feather bud develops with anterior posterior polarity, which is thought to develop in response to signals derived from specialized regions of mesenchymal condensation and epithelial thickening. These developmental processes are performed by cellular mechanisms, such as cell proliferation and migration, which occur during chick feather bud development. In order to understand the mechanisms regulating the formation of mesenchymal condensation and their role in feather bud development, we explanted chick dorsal skin at stage HH29+ with cytochalasin D, which inhibits cytoskeletal formation. We show that the aggregation of mesenchymal cells can be prevented by cytochalasin D treatment in a concentration-dependent manner. Subsequently, cytochalasin D disrupts the spacing pattern and inhibits feather bud axis formation as well. In addition, expression patterns of Bmp-4 and Msx-2, key molecules for early feather bud development, were disturbed by cytochalasin D treatment. Our results fully indicate that both the cytoskeletal structure and cell activity via gene regulation are of fundamental importance in mesenchymal condensation leading to proper morphogenesis of feather bud and spacing pattern formation.

Animals↗
PubMed1980

pathogenesis of the henny feathering trait in the Sebright bantam chicken. Increased conversion of androgen to estrogen in skin.

In female chickens of all breeds development of female feathering pattern is mediated by estrogens, whereas normal males and castrated chickens of both sexes develop male feathering. Male chickens carrying the henny feathering trait (such as the Sebright bantam and golden Campine) develop a female feathering pattern but otherwise virilize normally. To examine the possibility that the henny feathering trait is the result of increased conversion of androgen to estrogen in skin, estrogen formation from [1,2,6,7-3H]testosterone was measured in tissue slices from control breeds and chickens with the henny feathering trait. Rates of estrogen formation were undetectable or low in all control tissues other than ovary, whereas rates were high in skin and skin appendages and detectable in many tissues from Sebright and Campine birds. The increased rate of estrogen formation in skin was demonstrable in Sebright chicks and in all areas of skin biopsied in the mature bird. Furthermore, plasma levels of 17 beta-estradiol were higher in Sebright and Campine than in control male cocks. Thus, increased formation of estrogen from androgen in the peripheral tissues probably explains the henny feathering trait.

Androgens↗
PubMed2005

Characterization of a novel feather-degrading Bacillus sp. strain.

Feather waste is generated in large amounts as a byproduct of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. A feather-degrading bacterium was isolated from poultry feathers in decomposition. The strain identified as kr16 showed important feather-degrading activity when grown on basal medium containing 10 g/L of native feather as the source of energy, carbon, and nitrogen. The isolate was characterized according to the phenotypical characteristics and biochemical profiling that belong to the Bacillus genus. Keratinolytic activity of this isolate was monitored during cultivation of the bacterium on raw feathers at different temperatures. Maximum growth and feather-degrading activity were observed at 30-37 degrees C. The keratinolytic enzyme had a pH optimum ranging from 8.0 to 11.0 and a temperature optimum of 45-65 degrees C. The keratinase was strongly inhibited by EDTA and the metal ions Hg2+ and Sn2+.

Animals↗
PubMed1989

Effect of ruminal protein degradation of blood meal and feather meal on the intestinal amino acid supply to lactating cows.

Four lactating cows fitted with ruminal cannulae and T-type cannulae in the proximal duodenum and terminal ileum were utilized to measure protein degradation in the rumen and amino acid flow to and absorption from the small intestine. Soybean meal, blood meal, feather meal, and a 50-50 combination of blood meal and feather meal provided 50% of the protein in diets that contained 50% grain mix, 40% corn silage, and 10% alfalfa pellets on a DM basis. Ruminal degradation of dietary CP was 53, 43, 32, and 37% for diets containing soybean meal, blood meal, feather meal, and the combination of meals. Cows fed the latter two diets also had lower ruminal NH3 concentrations and efficiency of bacterial protein synthesis compared to those fed the soybean meal diet. Total tract N digestibility was lower for diets containing feather meal (63.4%) and a combination of meals (66.3%) than the soybean meal diet (78.5%). Total amino acid flow to the duodenum was 19.3 and 15.6% higher for cows fed the feather meal and combined meal diets, respectively, compared with the soybean meal diet. Total amino acid absorption from the small intestine was higher as well as absorption of individual amino acids for the combined meal diet compared with the soybean meal diet. Absorption of individual amino acids, expressed as a percentage entering the duodenum, was lowest for the feather meal diet. Results from this study show that feeding a combination of blood meal and feather meal instead of soybean meal can increase intestinal supply and absorption of amino acids in dairy cattle.

Amino Acids↗
PubMed1994

Flows of nitrogen and amino acids in dairy cows fed diets containing supplemental feather meal and blood meal.

Four Holstein cows, fitted with ruminal and duodenal cannulas, were used to determine the effects of supplemental feather meal and blood meal on ruminal fermentation and flows of N and AA to the duodenum. The basal diet contained (DM basis) 9.9% chopped alfalfa hay, 39.7% corn silage, 34.7% cracked corn, 8.2% corn starch, 2.1% vitamins and minerals, 4.4% casein, and 1% urea. A combination of feather meal and blood meal (3:1 on an N basis) was used to replace 0, 33, 67, and 100% of the casein and urea in the basal diet in a Latin square design. Intakes of DM, OM, and N were similar for all diets. Flows of total N, NAN, individual AA, total AA, and total essential AA were unaltered as supplemental feather meal plus blood meal increased. Flows of microbial N tended to decrease, but flow of non-ammonia, nonmicrobial N increased as supplemental feather meal plus blood meal increased. Increased proportions of dietary feather plus blood meal decreased the proportions of Ile, Lys, Met, and Thr in duodenal digesta. Molar percentages of ruminal pH and VFA were unchanged, but concentrations of ruminal NH3 N decreased linearly as supplemental feather meal plus blood meal increased. For the diets fed in this study, inclusion of one-third of the supplemental protein from feather plus blood meal resulted in maximum flows of NAN and microbial N to the small intestine.

Amino Acids↗
PubMed2003

Lead accumulation in feathers of nestling black-crowned night herons (Nycticorax nycticorax) experimentally treated in the field.

Although lead can attain high concentrations in feathers, interpretation of the biological significance of this phenomenon is difficult. As part of an effort to develop and validate noninvasive methods to monitor contaminant exposure in free-ranging birds, lead uptake by feathers of nestling black-crowned night herons (Nycticorax nycticorax) was evaluated in a controlled exposure study. Four- to 6-d-old heron nestlings (one/nest) at Chincoteague Bay, Virginia (USA), received a single intraperitoneal injection of dosing vehicle (control, n = 7) or a dose of lead nitrate in water (0.01, 0.05, or 0.25 mg Pb/g body wt of nestling; n = 6 or 7/dose) chosen to yield feather lead concentrations found at low- to moderately polluted sites. Nestlings were euthanized at 15 d of age. Lead accumulation in feathers was associated with concentrations in bone, kidney, and liver (r = 0.32-0.74, p < 0.02) but exhibited only modest dose dependence. Blood delta-aminolevulinic acid dehydratase activity was inhibited by lead, although effects on other biochemical endpoints were marginal. Tarsus growth rate was inversely related to feather lead concentration. Culmen growth rate was depressed in nestlings treated with the highest dose of lead but not correlated with feather lead concentration. These findings provide evidence that feathers of nestling herons are a sensitive indicator of lead exposure and have potential application for the extrapolation of lead concentrations in other tissues and the estimation of environmental lead exposure in birds.

Animals↗
PubMed1988

Psittacine beak and feather disease syndrome in a cockatoo.

Psittacine beak and feather disease syndrome was diagnosed in an adult sulfur-crested cockatoo with a history of chronic, progressive feather loss and beak necrosis. A definitive diagnosis was made on the basis of clinical signs and the observation of intracytoplasmic and intranuclear inclusions in involved feather follicular epithelium. Psittacine beak and feather disease syndrome develops in a variety of psittacine species and usually has a progressive and irreversible clinical course. Symmetric feather loss with replacement by severely dystrophic plumage is the salient clinical finding. Beak elongation and breakage also may be found. Treatment of diseased birds remains palliative and consists of a controlled environment, balanced nutrition, antibiotics, and autogenous vaccines. Avian practitioners should include psittacine beak and feather disease syndrome as a potential cause for pathologic feather loss in caged birds.

Animals↗
PubMed1993

Differential expression of three chick FGF receptor genes, FGFR1, FGFR2 and FGFR3, in limb and feather development.

Expression patterns of three fibroblast growth factor receptor genes, FGFR1 (cek1), FGFR2 (cek3) and FGFR3 (cek2), were observed in limb and feather morphogenesis. Expression of FGFR1 was observed in the mesoderm of limb bud, in the mesenchyme just underneath the feather placode, and then in the anterior mesenchyme of the feather bud. While expression of FGFR2 was observed in both surface ectoderm and mesenchymal aggregates corresponding to the future bones of the limb, the mesenchyme between the feather placode, and surface ectoderm of feather buds. Expression of FGFR3 was observed rather ubiquitously over mesoderm of limb and feather buds. Differential expression of these FGF receptor genes suggested that differential roles of these receptors in epithelia-mesenchymal interactions of limb and feather morphogenesis.

Animals↗
PubMed1993

Trace metals in primary feathers of the Barn Owl (Tyto alba guttatus) in The Netherlands.

The number of Barn Owls in The Netherlands has been reduced substantially over the last few decades. Death as a result of poisoning seems unlikely, but the pathology of all bird species found dead in The Netherlands between 1975 and 1988 (n = 15 422) shows that 21% of all the birds were contaminated. However, the most important factor responsible for the decline in Barn Owl numbers in The Netherlands has not yet been established. As a part of a new national protection plan for the Barn Owl, the role of heavy metals has been investigated. Concentrations of heavy metals in the primary feathers of the Barn Owl varied according to their position in the wing; especially As, Sb, Fe and Zn whose concentrations depended on the place of the primary feather in the wing and the part of the vane which is used for the monitoring. The HS7 feather vane appears to provide a good estimate, even though the metal concentrations of this feather are always slightly lower than the concentrations in mixed samples of all ten primaries. It is recommended that they are used as a standard. Many factors affect metal concentrations. Increasing levels with age are found, presumably because metals are stored during growth at the end of the feathers as a method of reducing possible harmful effects. No significant correlations were found between the metal concentrations in the organs and those in the feather. Kidney and liver concentrations are always lower than the generally accepted levels for pathological damage of these organs. Even though metal concentrations in Barn Owl feathers are high compared with those reported for other birds in the Netherlands, it is concluded that Barn Owls are not adversely affected by current levels of heavy metal contamination in The Netherlands.

Journal Article↗
PubMed2001

Reducing feather pecking when raising laying hen chicks in aviary systems.

Aviary systems for laying hens offer several advantages over battery cages. However, pecking the feathers of conspecifics remains a serious problem that negatively affects the welfare of the birds as well as the economy of a farm. From experimental studies with small groups, it has been shown that feather pecking and foraging behaviour are related and that both behaviour are influenced by early access to litter substrate. We, therefore, hypothesised, that feather pecking in aviaries can be reduced with an adequate management in the first 2 weeks of life.Each of seven pens on six commercial poultry farms, was divided into two identical compartments (matched pair design). In one of the compartments (experimental compartment) chicks were reared for the first 2 weeks of life with access to litter (wood shavings, in one case with additional straw), while the chicks in the other compartment (control) were kept on a plastic grid. Thereafter, all chicks had unrestricted access to litter and there were no differences between the two compartments neither in housing conditions nor in management procedures.Chicks in the experimental compartments spent significantly more time foraging (week 5), showed significantly less feather pecking (weeks 5 and 14) and significantly fewer birds had damaged tail feathers (weeks 5 and 14).The study demonstrates that in aviaries, under commercial conditions, early access to litter substrate has a significant effect on the development of feather pecking. In order to reduce feather pecking and to increase foraging behaviour, it is recommended that laying hen chicks raised in aviary systems do get access to litter from day 1 on.

Journal Article↗
PubMed1998

In vivo strains in pigeon flight feather shafts: implications for structural design

To evaluate the safety factor for flight feather shafts, in vivo strains were recorded during free flight from the dorsal surface of a variety of flight feathers of captive pigeons (Columba livia) using metal foil strain gauges. Strains recorded while the birds flew at a slow speed (approximately 5-6 m s-1) were used to calculate functional stresses on the basis of published values for the elastic modulus of feather keratin. These stresses were then compared with measurements of the failure stress obtained from four-point bending tests of whole sections of the rachis at a similar location. Recorded strains followed an oscillatory pattern, changing from tensile strain during the upstroke to compressive strain during the downstroke. Peak compressive strains were 2.2+/-0. 9 times (mean +/- s.d.) greater than peak tensile strains. Tensile strain peaks were generally not as large in more proximal flight feathers. Maximal compressive strains averaged -0.0033+/-0.0012 and occurred late in the downstroke. Bending tests demonstrated that feather shafts are most likely to fail through local buckling of their compact keratin cortex. A comparison of the mean (8.3 MPa) and maximum (15.7 MPa) peak stresses calculated from the in vivo strain recordings with the mean failure stress measured in four-point bending (137 MPa) yields a safety factor of between 9 and 17. Under more strenuous flight conditions, feather stresses are estimated to be 1.4-fold higher, reducing their safety factor to the range 6-12. These values seem high, considering that the safety factor of the humerus of pigeons has been estimated to be between 1.9 and 3.5. Several hypotheses explaining this difference in safety factor are considered, but the most reasonable explanation appears to be that flexural stiffness is more critical than strength to feather shaft performance.

Journal Article↗
PubMed1996

Sonic Hedgehog in feather morphogenesis: induction of mesenchymal condensation and association with cell death.

Sonic hedgehog is involved in vertebrate tissue interactions during development. During early feather development, Sonic hedgehog appears very early in epithelial placodes. During late feather development, Sonic hedgehog expression precedes the development of the marginal plates and is specifically localized in the marginal plate epithelium, which will later undergo cell death. By using retroviral vectors, exogenous Sonic hedgehog overexpression in developing feathers induced enlarged feather buds that have either lost their anterior-posterior polarity or exhibited reverse orientation. The enlarged dermal condensations may be mediated through broader TGF-beta 2 expression and reduced protein kinase C (PKC) expression. Reciprocal mesenchymal interaction is required for the induction and maintenance of Sonic hedgehog in the epithelial placodes. In scaleless mutant, Sonic hedgehog is absent in the apteric region and aberrantly expressed in the mesenchyme of the abnormal feather ridge. These findings suggest that Sonic hedgehog mediates key interactions between the epithelium and mesenchyme during feather morphogenesis.

Animals↗