166,434 research outputs found
Biofibre Production from Chicken Feather
No full textThe global poultry industry generates at least 2 million tonnes of chicken feather every year. Feathers are currently hydrolysed into meal used for animal feed and fertilizer. Feather consists of 91% keratin, 1% lipid and 8% water. Raw feather also contains preen oil, offal, faecal matter and poultry processing water. Its morphology consists of barbs extending at an angle from a central hollow rachis. Impurities coat the entire feather, and particulates are trapped by layers of barbules and hooked barbicels holding adjacent barbs together. These substructures present an extensive and tortuous hydrophobic surface. Feather fibre is a multipurpose, cost effective reinforcement for polymer composites. Its incorporation in plastic, wood, concrete and cardboard makes the product lighter, insulate from heat loss and improve sound attenuation properties. The objective of this study was to develop a process to produce clean fibre recovered from chicken feather. In the treatment process, the heterogeneous characteristics of feather had to be considered. Raw feather was suspended in 25 L water in a pulper to be decontaminated using 2 stages of 0.1485% sodium hypochlorite adjusted to pH 10.0 with 1 M sodium hydroxide and cleaned in 3 stages of 0.15% hydrogen peroxide. The pulper disc impeller agitated the suspension at 10 Hz for 30 minute at each stage. Bacteriological tests confirmed pathogens such as Campylobacter, Salmonella and Enterobacteriaceae were removed during treatment. Off-white clean feathers were more than 10% whiter than dull yellow raw feather. Cleaned feather was comminuted in 300 L water using a centrifugal pump at a flow rate of 30Hz on full recycle for 4 hours. Rachis and partially cut feather were removed using a 5 mm aperture filter and fibre was recovered using a 1 mm filter. Wet fibre was dried to constant mass in an air-forced oven at 70°C. Fibre yield was 27% of feather input, or 54% of theoretical yield. Surface morphology showed no damage
The effect of optimized lighting conditions on feather pecking and production of laying hens
No full textFeather pecking is one of the major problems in commercially kept laying hens. The current research considers the relevance of colour of light in the feather pecking problem
Studies of beak and feather disease virus infection
No full textThe circovirus Beak and feather disease virus (BFDV) causes psittacine beak and feather disease (PBFD) that is characterised by a chronic disease process associated with feather abnormalities, beak deformities and eventual death in various species of birds in the order Psittaciformes. This disease is seen in captive and wild psittacine species in Australia and several other countries and is a significant threat to the survival of some endangered psittacine species.
This thesis reports on genetic studies that have furthered the understanding of the diversity of BFDV present within Australia. These studies have optimised methods of detecting BFDV. They have also resulted in the production of an immunogenic and antigenic recombinant BFDV Capsid protein that could lead to alternate methods of producing viral antigen for serological tests and the development of a BFDV vaccine.
To assess the optimal method of the detection of BFDV infection, feather and blood samples were submitted by referring veterinarians throughout Australia from psittacine birds tentatively diagnosed with PBFD or with a history of being in contact with PBFD-affected birds. These samples were examined by 3 procedures commonly used to detect BFDV infection: a polymerase chain reaction (PCR) assay and haemagglutination (HA) for the detection of virus, and haemagglutination inhibition (HI) tests for the detection of virus antibody in response to infection. Of the samples examined from 623 psittacine birds, the prevalence of BFDV DNA in feather samples detected by PCR was 18.85%. There was a strong correlation between PCR and HA testing of feather samples, although possible false-positive and false-negative PCR and HA results were obtained in some samples. Of the 143 birds that were PCR feather-positive only 2 had detectable HI antibody and these birds were also HA feather-negative, which suggests that they were developing immunity to recent infection. All birds with HI antibody were feather HA negative.
Despite the rare occurrence of PBFD in cockatiels (Nymphicus hollandicus), 2 of the 13 samples collected from this species were PCR and HA positive indicating that this species can be infected with BFDV.
Three studies were undertaken to further our understanding of the genetics of BFDV in Australian avifauna: sequence analysis of the BFDV detected in a grey cockatiel (Nymphicus hollandicus), a species normally considered resistant to infection with BFDV; analysis of the genome of BFDV present in lorikeets (Trichoglossus sp.) in Australia; and analysis of the genome of BFDV detected in endangered swift parrots (Lathamus discolor). Sequence analysis of the entire genome of the cockatiel BFDV isolate revealed that it clustered phylogenetically with 2 other viruses, one from a sulphur crested cockatoo (SCC1-AUS) and one from a Major Mitchell cockatoo (MMC-AUS), which suggests that this isolate from the grey cockatiel was not a cockatiel-specific biotype. Phylogenetic analysis of the ORF V1 of BFDV detected in 7 lorikeets demonstrated these 7 isolates clustered phylogenetically with other BFDV isolates obtained from Loriidae species elsewhere in the world and confirmed the presence of a loriid-specific genotype. Phylogenetic analysis of the sequence data generated from ORF V1 of virus detected in 2 endangered swift parrots provided evidence they were also infected with BFDV genotypes derived from other species of birds, one isolate clustering with viruses from a Loriidae genotype and the other with isolates derived from species of Cacatuidae and Psittacidae.
As part of this research, a baculovirus expression system was successfully developed for the production of recombinant BFDV Capsid protein. Inoculation of this protein into chickens resulted in the development of HI antibody, which demonstrated its immunogenicity. When used as an antigen in HI tests it detected antibody in virus-infected birds, which demonstrated its antigenicity. This protein offers potential application as an antigen for the development of serological tests and as an immunogen for incorporation into vaccines for control of PBFD
Divergent selection on feather pecking behaviour in laying hens (Gallus gallus domesticus)
No full textA selection experiment was initiated in 1996 in which selection for (HP line) and against (LP line) feather pecking was performed. The foundation stock was a White Leghorn layer strain established in 1970 and maintained since then as a random bred control line at the Institute. Six hatches were produced over three generations. At the age of 68 wk (gen. 0, 1996), 35 wk (gen. 1, 1997), 30 wk (gen. 2, 1998), and 27 wk (gen. 3, 1999) female birds were transferred to observation pens and their feather pecking behaviour was recorded. In each generation, 30 females and 8 males were selected from approx. 200 females and 60 males. Selection criteria was breeding value estimated by animal model on the trait ‘number of bouts of feather pecking per bird per hour’.
Feather pecking behaviour in adult hens was significantly higher in HP than in LP. In generation 2 the following was recorded: Bouts per bird per hour (3.10 versus 1.37, P<0.01), pecks per bird per hour (7.04 versus 3.58, P<0.05) and proportion of hens recorded feather pecking in the 180 minutes observation period (67 versus 56%, P<0.05). In generation 3 the following was recorded: Bouts per bird per hour (4.56 versus 0.63, P<0.001), pecks per bird per hour (13.9 versus 2.51, P<0.001) and proportion of hens recorded feather pecking in the 180 minutes observation period (75 versus 49%, P<0.001).
In generation 3, plumage condition was better in LP on neck, breast, back, wings and tail, as well as overall (P<0.001). Body weight did not differ between lines in generation 2, but in generation 3, HP hens were on average heavier than LP hens at the age of 27 weeks (1435 g versus 1371 g, P<0.001)
Leonard Feather with unidentified persons
No full text11 3/4 x 15 3/4 inch photograph; Leonard Feather with unidentified persons, including a photographer, wearing a ""staff"" name tag with the letter ""J"" on i
Across-Line SNP Association Study for Direct and Associative Effects on Feather Damage in Laying Hens
No full textAn association study between SNP markers and feather condition score on the back, rump and belly of laying hens was performed. Feather condition score is a measure of feather damage, which has been shown to be closely related to feather pecking behaviour in hens housed in groups. A population of 662 hens was genotyped for 1536 SNPs of which 1022 could be used for the association study. The analysis was conducted across 9 different lines of White Leghorn and Rhode Island Red origin. Across lines linkage disequilibrium is conserved at shorter distances than within lines; therefore, SNPs significantly associated with feather condition score across lines are expected to be closer to the functional mutations. The SNPs that had a significant across-line effect but did not show significant SNP-by-line interaction were identified, to test that the association was consistent across lines. Both the direct effect of the individual’s genotype on its plumage condition, and the associative effect of the genotype of the cage mates on the individual’s plumage condition were analysed. The direct genetic effect can be considered as the susceptibility to be pecked at, whereas the associative genetic effect can be interpreted as the propensity to perform feather pecking. Finally, 11 significant associations between SNPs and behavioural traits were detected in the direct model, and 81 in the associative model. A role of the gene for the serotonin receptor 2C (HTR2C) on chromosome 4 was found. This supports existing evidence of a prominent involvement of the serotonergic system in the modulation of this behavioural disorder in laying hens. The genes for IL9, IL4, CCL4 and NFKB were found to be associated to plumage condition, revealing relationships between the immune system and behaviour
Development of novel diagnostic and vaccine options for beak and feather disease virus (BFDV)
No full textBeak and Feather Disease Virus (BFDV) is a circovirus which causes ill-thrift, feather loss and immunosuppression leading to secondary infections and eventually death in psittacine birds. The development of standardised reagents for the detection and characterisation of BFDV infections and for the production of protective vaccines has been difficult as no cell culture system has yet been found to grow the virus successfully in vitro. However, the development of consistent and effective diagnostic tests and vaccines is now more practical through the application of nucleic acid-based detection methods and recombinant technology.
A quantitative real-time PCR assay for the detection of BFDV DNA was developed, using primers designed to amplify a conserved 81 bp fragment of ORFV1 and SYTO9, a fluorescent intercalating dye, with assays run on a Corbett RotorGene 3000. A synthetic oligonucleotide was used to establish standard curves for the quantitation of viral load in both blood and feather preparations. The assay was very sensitive, with a detection limit of 50 copies/ìL. The assay was developed using BFDV-positive DNA extracts from the feathers of 10 different species of birds and validated with blood and feather samples from corellas vaccinated with an experimental BFDV vaccine, then challenged with live virus. Viral DNA was reliably detected in the blood of all control (non-vaccinated) birds and in some vaccinated birds. Contamination of the environment with the feather dander of BFDV-infected birds meant that HA feather preparations were unreliable for the detection and quantitation of viral excretion. Nonetheless, the assay should prove to be a useful and sensitive test for the detection of viral DNA in a range of samples in future investigations.
A recombinant BFDV capsid protein was also produced and a specific monoclonal antibody developed against it. The behaviour of the protein in haemagglutination (HA) assays and the behaviour of the monoclonal antibody in western blotting, immunohistochemistry (IHC), ELISA and haemagglutination-inhibition (HI) assays were characterised. The protein had the ability to agglutinate galah erythrocytes as per the wild-type virus and this agglutination was successfully inhibited by antibodies to wild-type BFDV from naturally immune psittacine birds. Furthermore, the protein self-assembled into virus-like particles as determined by electron microscopy. The antibody was specific for both the recombinant BFDV capsid protein and the whole virus and had similar optimal titres when used in western blotting and IHC. The antibody also had HI activity and detected BFDV virus from 3 genera of psittacine birds, including the recently described cockatiel BFDV isolate. A novel “blocking” (or “competitive”) ELISA (bELISA) for the detection of anti- BFDV antibodies in psittacine sera (Ab-bELISA) was also developed and validated with 166 samples from eastern long-billed corellas vaccinated with the recombinant capsid protein and challenged with live virus. The bELISA was found to be both sensitive and specific and correlated strongly with the HI test, thus it should have wide application for the serodiagnosis of BFDV.
A survey of cockatiels (n=88) housed at commercial aviaries was conducted to investigate whether BFDV infection occurs in cockatiels. All birds were diagnosed as being virus-free by PCR and HA and had no detectable antibody titre by HI assay. In addition to this, the genomes of two BFDV isolates obtained from diseased cockatiel feathers were sequenced and cross-reactivity assays performed using virus eluted from these feathers and sera from naturally immune psittacine birds. Serological cross-reactivity results and phylogenetic analysis of the nucleotide sequences indicated that the cockatiel virus isolates were serologically and genetically different to other BFDV isolates. This is the first report of an antigenically distinct BFDV in psittacine birds. Since the Ab-bELISA has a lower limit of detection than the HI assay, it was used to repeat the cockatiel sero-survey. No antibodies were detectable in any of the cockatiels tested and thus questions about the real prevalence of BFDV infection in cockatiels and the possible existence of a novel BFDV serotype adapted to cockatiels remain unanswered.
The successful control of PBFD in both pet and wild birds depends on the development of vaccines that incite a strong specific immune response and can be efficiently produced in large quantities. Recombinant BFDV capsid proteins have recently been considered as candidate vaccines against BFDV and recombinant techniques allow the development of other candidate vaccines, including DNA vaccines. In order to examine the potential of DNA vaccination as a strategy for the prevention and control of BFDV, two DNA vaccines, based on the nucleotide sequence encoding the capsid protein of BFDV, were developed using the mammalian expression vector pVAX1. The vaccine constructs encoding both the full length and NLS-truncated capsid protein resulted in protein expression both in vitro and in vivo. Protein was detected in COS-7 cells transfected with the constructs with an indirect immunocytochemistry assay using the monoclonal antibody described in Chapter 5. Protein was present in the nucleus of cells transfected with the vaccine encoding the full-length nucleotide sequence and in the cytoplasm of cells transfected with the vaccine encoding the NLS-truncated sequence as expected. Both DNA vaccine constructs induced detectable levels of anti-BFDV antibodies in vaccinated birds, determined using the Ab-bELISA described in Chapter 5. Thus, DNA vaccines similar to those presented here may have application in the prevention and control of BFDV and some options for the further development of these vaccines into effective methods for the control of BFDV are discussed
Frank Cook & J. Otis Williams Blindfold Test
No full textRecording identified as most likely Frank Cook and J. Otis Williams participating in one of Leonard Feather's blindfold tests
Symbioses between cyanobacterial communities and feather mosses in boreal forests and consequences for dinitrogen fixation
No full textFeather moss-cyanobacteria associations, although still poorly understood, are recognised as essential for the regulation of nitrogen (N) input into N-limited ecosystems such as boreal forests due to their ability to carry out N2-fixation. This thesis aimed to investigate the diversity and composition of feather moss-associated cyanobacterial communities, the mechanisms by which cyanobacterial colonisation on mosses occurs and the fate of the N that they fix, and how various combinations of biotic and abiotic conditions influence cyanobacterial N2-fixation activity. The results demonstrated that the cyanobacterial communities associated with these mosses are highly host-specific and diverse, with moss species identity rather than environmental factors being the primary driver of their composition and diversity. Furthermore, cyanobacterial colonisation on feather mosses appears to be possible only if the plants are able to produce a chemo-attractant (to attract and guide cyanobacteria towards colonisation sites), the plant eventually gaining N from the cyanobacteria according to its needs. Moreover, the results reveal that both abiotic (light intensity, temperature) and biotic (host plant presence, cyanobacterial community composition, cyanobacterial density) factors must be considered when studying what causes variation in feather moss-cyanobacteria N2-fixation rates over time and space. Overall, the results of this thesis help in developing our understanding of the drivers of cyanobacterial communities on boreal feather mosses, and highlight the important role that these mosses play in the N cycle in boreal forest ecosystems, by hosting cyanobacteria and acquiring the N2 that they fix. In addition, this work also contributes to a better understanding of the complex interactions regulating biological N2-fixation, a major driver of ecosystem processes
Psittacine beak and feather disease : vaccination, haematological response and pcr methodology
No full textTo enable assessment of recombinant BFDV capsid protein (recBFDVcap) for vaccination to protect against PBFD, commercially available lovebirds (Agapornis sp.) were tested for evidence of past and current BFDV infection using PCR, HI and HA to identify suitable BFDV-free birds in which to test the vaccine. During this attempt, it was found that lovebirds from commercial aviaries were endemically infected with BFDV with evidence of up to 100% prevalence of BFDV DNA in blood samples from individual birds over time. Such an approach was abandoned as unlikely to yield suitable numbers of naïve birds to conduct a BFDV vaccination trial.
As commercially available lovebirds were considered to be a poor source of BFDV-free birds, wild caught cockatoo nestlings and eggs (long-billed corella; Cacatua tenuirostris and galah; Eolophus roseicapillus) were used to assess the efficacy of BFDV vaccination using baculovirus recombinant BFDV capsid. Eggs were artificially incubated and 3 eggs successfully hatched and 1 was successfully hand-reared. All nestlings were screened for BFDV DNA in blood using PCR upon arrival then on days 11, 18 and 25 and tested for anti-BFDV antibody on the day of arrival. All hatched birds were determined to be free of BFDV DNA and BFDV HI antibody in the peripheral blood throughout the hand rearing period and the flock was considered to be suitable for a BFDV vaccination trial.
Corellas (n=13) were injected with 1 mL of vaccine containing 10 μg recBFDVcap on day 0 and 0.4 mL vaccine containing 66.8 μg recBFDVcap on day 11. All vaccinated corellas and 5 non-vaccinated control corellas were given 0.4 mL BFDV suspension (titre = log2 12 HAU/50 μL) intramuscularly and 0.1 mL orally 16 days after booster vaccination. Blood was collected periodically during the vaccination period and blood and feathers collected before and after BFDV administration. Testing included BFDV DNA detection by PCR and qRT PCR (on blood) as well as serum antibody detection by haemagglutination inhibition (HI) and BFDV DNA and antigen was detected by qRT PCR and haemagglutination (HA) (on feathers), respectively. Four of 97 blood samples collected from vaccinated birds post BFDV challenge tested positive by PCR, whereas 17 of 35 samples taken from non-vaccinated control corellas tested positive. Vaccinated birds did not develop feather lesions, had only transient PCR detectable viraemia and had no evidence of persistent infection 270 days post-challenge using PCR, histopathology and immunohistochemistry (IHC). Non-vaccinated control corellas developed transient feather lesions and PCR, HI and HA test results consistent with PBFD. They were BFDV PCR positive for up to 41 days post-challenge and qRT PCR demonstrated reduced virus replication in vaccinated birds compared to non-vaccinated control birds. Thus, administration of recBFDVcap vaccine alone was found to incite an adaptive immune response in BFDV-free corellas that subsequently conferred protection against inoculation with BFDV.
A commonly utilized method for excising blood dried on filter paper was proven to be of high risk of carryover contamination facilitated by a hole punch used for processing several samples. Therefore a practical method of avoiding carryover contamination was developed and used in the DNA testing procedures of the vaccination trial.
Finally, the haematological characteristics of the above mentioned cockatoos were studied before and for 97 days after experimental infection with BFDV. It was found that the pre-challenge haematological values were similar between the vaccinated and non-vaccinated corellas. Most pre-challenge parameters were comparable to previously reported values of other cockatoos and psittacine birds. Significant differences were seen in both groups when comparing pre-challenge values with post challenge values for total and differential leukocyte concentrations, but PCV and TSP were not significantly affected by BFDV challenge
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