Giant cell tumor of the bone in a scarlet macaw (Ara macao)

A 6-mo-old female scarlet macaw (Ara macao) was presented after a 2-mo period of anorexia and weakness. The bird was reluctant to fly 1 wk before referral due to a painful left wing. Physical examination revealed a firm swelling around the left shoulder. On radiographs, the diaphysis and proximal metaphysis of the left scapula were radiolucent. Computer tomography revealed an osteolytic process, suggestive of a bone tumor, affecting the left scapula. Cytology of a fine needle aspiration biopsy of the mass showed erythrocytes, a proliferation of spindle-shaped mesenchymal cells, and multinucleated giant cells (osteoclasts) suggestive of a giant cell tumor. The left wing, including the scapula, was amputated. The bird showed a fast recovery but died 1 hr later. Findings during the pathological examination were compatible with shock due to blood loss. The shoulder process was characterized as a giant cell tumor. To our knowledge, this is the first complete report of a giant cell tumor of the bone in a bird.     

Genetic characterization, pathogenicity, and protection studies with an avian adenovirus isolate associated with inclusion body hepatitis

An avian adenovirus (AAV) was isolated from liver samples of two 2-wk-old broiler-breeder flocks obtained from grandparents vaccinated at 10 and 17 wks of age with an autogenous inactivated vaccine containing the European AAV 8 (8565 strain) and 11 (1047 strain) serotypes (AAV8/11 vaccine). Affected broiler-breeders exhibited clinical signs and macroscopic and microscopic lesions associated with inclusion body hepatitis (IBH). The isolated adenovirus, identified as Stanford, was molecularly characterized as European serotype 9. The pathogenicity of the Stanford strain was confirmed after inoculation of specific-pathogen-free (SPF) chickens at 1-7 days of age, causing 100% and 20% mortality, respectively. The level of protection against IBH was evaluated in two broiler-breeder progenies from AAV 8/11-vaccinated grandparent flocks and a commercial broiler flock by challenge at 1 or 7 days of age with the AAV 8 and 11 serotypes and/or the Stanford strain. The broiler-breeder progenies and the commercial broiler flock exhibited protection against IBH after challenge. No significant differences in mean body weights were observed at 3 wk of age in any of the evaluated groups. We conclude that broiler-breeder progenies from 30- to 50-wk-old grandparents vaccinated with the AAV 8/11 vaccine were adequately protected against challenge with the AAV 8 and 11 serotypes and the Stanford strain.     

Stress responses in adult cattle due to surgical dehorning using three different types of anaesthesia

Dehorning adult cattle is a surgical procedure causing distress of varying intensities that can be reflected in behavioural changes and alterations in plasma cortisol levels. Stress responses during the dehorning process were evaluated in 18 Red Pied cows. The cows were divided into 3 groups of six and kept in tie-stall housing. Those in the first group were dehorned under general anaesthesia (GA) induced by intravenous administration of xylazine and ketamine. The second group was dehorned under sedation and local anaesthesia (SLA) induced by intramuscular administration of xylazine and local anaesthesia with lidocaine. The third group was dehorned under local anaesthesia (LA) with lidocaine. Dehorning was performed with a foetotomy wire. Blood samples were taken 0.5 h before dehorning to determine cortisol levels, and, by means of a central venous catheter inserted into the jugular vein, during surgery at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7 and 8 h post-surgery. Concurrently, occurrence of stress behaviours was assessed. Cortisol levels were measured by enzyme immunoassay (EIA). The lowest mean peak levels of plasma cortisol (82.53 +/- 6.04 nmol l(-1)), the most rapid return of plasma cortisol levels to baseline values (1.92 +/- 1.11 h), and the lowest occurrence of stress behaviours (2.38 +/- 5.83%) were noted in the SLA group. The highest mean peak levels plasma cortisol (113.86 +/- 25.65 nmol l(-1)), the slowest return of plasma cortisol levels to baseline values (3.83 +/- 2.18 h) and the most frequent occurrence of stress behaviours (65.48 +/- 28.72%) were observed in the LA group. There were significant differences between the SLA and LA groups in peak plasma cortisol levels (p = 0.011) and in occurrence of stress behaviours (p = 0.003). Sedation induced by intramuscular administration of xylazine in conjunction with local anaesthesia with lidocaine is considered the most suitable method of anaesthesia when dehorning adult cattle. Local anaesthesia with lidocaine alone was least suitable.     

Hagberg falling number and the nutritional value of wheat in broiler chicken diets

1. Three experiments were performed to study the effect of Hagberg falling number in wheat on performance, nutrient digestibility and AMEN in broilers. In two experiments, one hard and one soft wheat variety were used to study the interaction between falling number and hardness of wheat with regard to nutritional value. In these experiments, wheat batches with high falling number when harvested under dry conditions were used in broiler diets. 2. Wheat with reduced falling numbers (high, medium and low) was obtained by controlled germination. In the third experiment, wheat with reduced falling numbers were obtained by delayed harvesting times. 3. In each experiment, a total of 4 cereal batches with different falling numbers from each wheat variety were used to produce corresponding experimental diets with wheat as the major ingredient. Each diet was fed to broiler chickens ad libitum from d 1 to d 17 of age. 4. There was no consistent effect of falling number on performance. Low falling number did not improve feed utilisation or AMEN compared to the original wheat, despite a higher AMEN associated with higher starch digestibility. This phenomenon was not observed after reduction of falling number by delayed harvesting. Apparently, natural reduction of falling number resulted in enhanced degradation of arabinoxylans compared to controlled germination.     

Pharmacological characterisation of the electrically evoked release of monoamines from chicken brain in vitro

1. A study was conducted to develop an in vitro model for examining the basal and electrical-stimulation-induced release of [3H]monoamines from chicken hyperstriatal neurones in order to demonstrate the presence of presynaptic autoreceptors for the three main monoamine transmitters: noradrenaline, dopamine and 5-HT. 2. Two sets of experiments were carried out: the first was to evaluate the effect of calcium and tetrodotoxin (TTX, sodium channel conductance inhibitor) in order to demonstrate that evoked release of monoamines was a consequence of exocytotic processes; the second to investigate the effect of selective agonists and antagonists on neurotransmitter release. 3. Ross and Cobb broiler chickens of either sex (approximately 7 to 8 weeks old) were used. Slices of hyperstriatal tissue were preincubated with [3H]noradrenaline, [3H]dopamine or [3H]5-hydroxytryptamine (5-HT), washed, perfused and electrically stimulated at three time points (S1, S2 and S3) which released [3H]noradrenaline, [3H]dopamine and [3H]5-HT, as determined by scintillation spectrometry. 4. When calcium was removed from, or TTX added to, the superfusion medium prior to and including the second period of electrical stimulation (S2) the evoked releases of [3H]noradrenaline, [3H]dopamine and [3H]5-HT at S2 were abolished. 5. In the presence of the selective alpha2-adrenoceptor agonist UK 14304 during the S2 period, the S2/S1 ratio was lower than the control ratio due to a reduction in the stimulated release of [3H]noradrenaline. The selective alpha2-adrenoceptor antagonist RX 821002 blocked the UK 14304-induced reduction of evoked release and the S2/S1 ratio was similar to the control ratio. 6. The D2-like receptor agonist quinpirole reduced the S2/S1 ratio for [3H]dopamine release, an effect blocked by the antagonist AJ 76. The 5-HT1B receptor agonist CP 94253 during S2 reduced the S2/S1 ratio due to a reduction in evoked [3H]5-HT. This effect was blocked by the 5-HT1B receptor antagonist GR 55562. 7. The results demonstrate, for the first time, the functional presence of presynaptic alpha2-adrenoceptors, presynaptic 5-HT1B autoreceptors and presynaptic D2-like autoreceptors in broiler chicken hyperstriatal neurones in vitro.     

Evaluation of the effectiveness of two infectious bronchitis virus vaccine programs for preventing disease caused by a California IBV field isolate

Infectious bronchitis virus CA99 serotype was isolated from several broiler flocks in Northern California. The virus caused late-onset respiratory disease and increased airsacculitis condemnation in affected flocks despite the use of an established infectious bronchitis virus vaccination program. An experimental study compared Holland/Arkansas and Massachusetts/Arkansas vaccination protocols to determine the efficacy of commercial infectious bronchitis virus vaccines in reducing respiratory disease and airsacculitis lesions found at processing that were associated with a CA99 field isolate. All vaccination groups were given Massachusetts/Connecticut strains of infectious bronchitis virus vaccines at age 1 day followed by vaccination with either Holland/ Arkansas or Massachusetts/Arkansas vaccine strains at 18 days of age. Birds were challenged at age 31 days with a CA99 field isolate. Gross pathology, histopathology, and virus isolation were evaluated. Chickens vaccinated with Holland/Arkansas had marginally better protection against CA99 challenge than chickens vaccinated with Massachusetts/Arkansas, although differences were not statistically significant.     

Epidemiologic investigation of an outbreak of goose parvovirus infection in Sweden

An outbreak of goose parvovirus (GPV) infection on a Swedish goose farm in the spring of 2004 increased the mortality rates from 2% in the early unaffected hatches to 90% and 99% respectively in the two hatches following virus introduction and 40% in goslings hatched later in the same breeding season. In this paper we describe the clinical observations, diagnostic procedures, and epidemiologic investigation carried out to elucidate the source of the infection. The diagnosis was confirmed by serology, virus isolation, and sequence analysis of a 493-bp-long fragment of the VP1 gene. Phylogenetically the causative virus was closely related to pathogenic GPV strains isolated in 2003 and 2004 from Poland and the United Kingdom, respectively. The Swedish isolate exhibited less homology with pathogenic strains from Hungary and Asia and with attenuated vaccine strains. The epidemiologic investigation showed that the virus was first introduced to a contract farm (farm A) and then was transferred with newly hatched goslings to the farm that had submitted the birds for necropsy (index farm). The exact time and source of the virus introduction to farm A could not be determined with absolute certainty. Possible sources of the infection included backyard goose eggs that had been delivered to farm A for subcontract incubation and hatching, wild geese that frequented the flock of breeding geese on pasture on farm A, and a clutch of Canada goose eggs (Branta canadensis) that had been produced by wild geese and was hatched in the same machine as the eggs produced by farm A.     

Rapid quantification of avian eggshell microstructure and crystallographic-texture using two-dimensional X-ray diffraction

1. It is important to quantify eggshell microstructure because it may influence eggshell mechanical properties and could be of importance for eggshell quality assessment. It also provides information about changes in eggshell associated with different hen physiological conditions. 2. This paper describes an alternative methodology which, based on 2D X-ray diffraction, allows eggshell microstructure quantification (for example, crystal size and orientation) much more efficiently than using traditional techniques (optical or scanning electron microscopy and conventional X-ray diffraction). 3. For such analyses, an X-ray diffractometer equipped with an area detector is used. Such equipment collects the diffraction pattern of the sample in one single exposure (taking a few tens of seconds), thus considerably reducing data acquisition time. 4. The two-dimensional diffraction patterns obtained contain detailed information about size and crystallographic orientation of crystals forming the eggshell. This information can be automatically extracted using specially designed software. 5. Access to the software is available on a website, the address of which is given in the Materials and Methods section. 6. In this paper, specific examples of how these analyses are applied are set out and recommendations for obtaining different types of microstructure information are given. In addition, the limitations of the technique are discussed.