Experimental Pigeons Research Articles

Патоморфологічні зміни у домашніх голубів за експериментального зараження Eimeria species

Goal. To establish pathomorphological changes in the internal organs of domestic pigeons (Columba livia domestica Linnaeus, 1758) in experimental eimeriosis. Methods. Methods used: clinical observation, coprological examination, pathological autopsy of experimental pigeons, analysis of sectional studies, histopathological examination of samples of selected organs (intestine, liver, spleen and bursa of Fabricius). Experimental clinically healthy pigeons were experimentally infested orally by sporulated culture of Eimeria spp. (E. labbeana — 74.6%, E. columbae — 21.9%, E. columbarum — 3.5%). Then for 8 days they studied the dynamics of oocyst secretion by the Fulleborn method, after which birds were euthanized with subsequent pathomorphological studies. Results. The data obtained indicate that in experimental eimeriosis in adult pigeons develop: moderate hyperplasia of lymphoid nodules of the villi of the duodenum, diffuse superficial desquamative duodenojeunitis with serous edema and lymphocytic infiltration of intestinal hemorrhage and lymphocytic infiltration of intestinal villi, spleen congestion with the development of local or diffuse hemosiderosis, delayed involutional atrophy of nodules in the bursa of Fabricius, hyperplasia of lymphoid nodules of the liver, the development of moderate degenerative changes in hepatocytes, hemostasis in the central and interparticle veins. Conclusions. In pigeons with acute experimental eimeriosis, according to the results of the study, dominated the hyperplastic processes of lymphoid structures located in the intestinal villi of the duodenum, spleen, Fabricius bursa, and liver. Signs of delay of involutionary processes are revealed in Fabricius’s bursa. In the intestinal tract, the most severe pathologies were localized within the duodenum and small intestine.

Evaluation of Performance and Yield Stability Analysis Based on AMMI and GGE-Biplot in Promising Pigeonpea [Cajanus cajan (L.) Millspaugh] Genotypes

Background: Pigeon pea is considered an excellent and affordable source of plant-based protein, essential amino and fatty acids, fibers, minerals and vitamins with consistent source of income and employment to small and marginal farmers and thus holds premier position in the world agriculture. Shifts in rainfall patterns and seasons due to climatic change require the development of varieties with stable and high yield over a wide range of environmental conditions became major objective of crop improvement. Methods: The present study was carried out to ascertain the stable genotypes, environments discrimination and genotype by environment crossovers using different stable models by conducting Multi-location pigeon pea trial in five environments during Kharif, 2018 in Randomized Complete Block Design. Stability analysis for grain yield was performed by deploying the AMMI (Additive Main Effects and Multiplicative Interaction) model and GGE (Genotype and Genotype by Environment) biplot method. The pigeon pea genotype WRG-330 was found superior among all the genotypes over checks over locations, while, WRG-327 exhibited almost minimum interaction with the environments convincing the reliability of the performance. The test environments at Adilabad and Tandur were observed representative with better discriminating ability. Conclusion: It is concluded that there is no large difference between the AMMI and GGE biplot analyses in evaluation of experimental pigeon pea genotypes in different locations and both methods revealed similar results convincing that both methods can be used equally.

Experimental pigeon paramyxovirus-1 infection in chicken: evaluation of infectivity, clinical and pathological manifestations and diagnostic methods.

Several pigeon paramyxovirus-1 (PPMV-1) outbreaks in feral pigeons were described recently in Switzerland. The potential of PPMV-1 to induce the notifiable Newcastle disease in chickens is discussed controversially. Therefore, in order to study epidemiologically relevant parameters such as the kinetics of PPMV-1 replication and shedding as well as seroconversion after infection, chickens were infected experimentally with a Swiss PPMV-1 isolate. This generated also defined sample material for the comparison of diagnostic tests. The infectivity of the Swiss PPMV-1 isolate for chickens was demonstrated successfully by virus shedding after experimental inoculation. Our data suggest that long-lasting shedding for up to 60 days can occur in chickens infected with PPMV-1. The isolate used here was of low pathogenicity for chickens. Different quantitative reverse transcription PCR assays were evaluated with a set of Swiss PPMV-1 isolates, and various samples from experimentally infected chickens were analysed with respect to their suitability for viral RNA detection. At 14 days post-infection, virus genome was detected mainly in spleen, caecal tonsils, heart, cloacal swabs, liver, proventriculus, duodenum and kidney tissue samples. Overall, the level of virus replication was low. Not all assays used routinely in diagnostics were capable of detecting viral genome from the isolates tested. Possible explanations are the genetic divergence of PPMV-1 and the low level of viral RNA in the samples. In contrast, two methods that are not used routinely proved more suitable for virus-genome detection. Importantly, the collection of material from various different organs is recommended, in addition to the kidney and brain analysed routinely. In conclusion, this study shows that there is a need to reconsider the type of samples and the protocols used for the detection of PPMV-1 RNA in chickens.

THE INTERRELATION BETWEEN PIGEONS’ SCHEDULE-INDUCED AGGRESSIVE BEHAVIOR AND THE RECIPIENTS’ COUNTER-BEHAVIOR

The present experiment was conducted to investigate whether an experimental pigeon's shield-peck responses toward a target pigeon could be induced by a food reinforcement schedule consisting of continuous reinforcement (CRF) and extinction. Further, the interaction between experimental and target pigeons’ shield-peck responses was investigated. The experiment was an ABAB design consisting of alternating phases of nonreinforcement (A) and CRF-extinction (B) of the experimental pigeons' key-peck responses unrelated to their shield-peck responses. The experimental pigeons' shield-peck responses were induced by the CRF-extinction schedule. Further, there were positive correlations between the experimental and the target pigeons' shield-peck responses revealing a similar trend in both their response rates. Thus, the experimental pigeons’ shield-peck responses were controlled by variables including the reinforcement schedule and social stimuli including ontogenic and phylogenic variables derived from their target pigeons. Moreover, the pigeons' responses could be classified as an aggressive behavior derived from the interlocking contingencies of the responses of the pigeons of the dyads.

An evaluation of the impact of aloe vera and licorice extracts on the course of experimental pigeon paramyxovirus type 1 infection in pigeons

The progressive decrease in the efficiency of synthetic drugs has prompted research into phytogenic feed additives with potentially immunomodulatory and anti-infective properties. Complex diseases with a mixed etiology, including viral, pose a growing problem in domestic pigeons. The aim of this study was to determine the effectiveness of various doses of aloe vera and licorice extracts on the course of experimental PPMV-1 infection in pigeons. The experiment was performed on pigeons divided into 5 groups, including one control group and 4 experimental groups, which were orally administered aloe vera or licorice extracts at 300 or 500 mg/kg BW for 7 d after experimental inoculation with PPMV-1. On d 4, 7, and 14 after inoculation, cloacal swabs and samples of organs were collected from 4 birds in each group. The samples were analyzed to determine the copy number of PPMV-1 RNA by TaqMan qPCR. The results indicate that licorice and aloe vera extracts inhibited PPMV-1 replication by decreasing viral RNA copy numbers in the examined organs. The most inhibitory effect was observed in pigeons receiving aloe vera extract at 300 mg/kg BW, for which PPMV-1 RNA copy numbers were approximately 7-fold lower (brain), 9-fold lower (kidneys), and 14-fold lower (liver) than in the control group. The results of this study point to the potentially antiviral effects of aloe vera and licorice extracts in pigeons infected with PPMV-1. To the best of our knowledge, this is the first study to investigate the antiviral properties of aloe vera and licorice extracts in domestic pigeons.

Resurgence of time allocation.

The resurgence of time allocation with pigeons was studied in three experiments. In Phase 1 of each experiment, response-independent food occurred with different probabilities in the presence of two different keylights. Each peck on the key changed its color and the food probability in effect. In Phase 2, the food probabilities associated with each keylight were reversed and, in Phase 3, food was discontinued in the presence of either keylight. The food probabilities were .25 and .75, in Experiment 1, and 0.0 and 1.0 in Experiment 2. More time was allocated to the keylight correlated with more probable food in Phases 1 and 2, and in Phase 3 resurgence of time allocation occurred for two of three pigeons in Experiment 1, and for each of four pigeons in Experiment 2. Because time had to be allocated to either of the two alternatives in Experiments 1 and 2, however, it was difficult to characterize the time allocation patterns in Phase 3 as resurgence when changeover responding approached zero. In Experiment 3 this issue was addressed by providing a third alternative uncorrelated with food such that in each phase, after 30 s in the presence of either keylight correlated with food, the third alternative always was reinstated, requiring a response to access either of the two keylights correlated with food. In this experiment, the food probabilities were similar to those in Experiment 1. Resurgence of time allocation occurred for each of three pigeons under this procedure. The results of these experiments suggest that patterns of time allocation resurge similarly to discrete responses and to spatial and temporal patterns of responding.

Phylogenetic, antigenic and biological characterization of pigeon paramyxovirus type 1 circulating in China

BackgroundFor many years, ND has been one of the most important infectious pigeon diseases in China. In recent years, a high mortality has been observed in ND-infected pigeons in China. Mortality is from 40% to 80% or 100% in some cases.MethodsThe full-length genomes of four pigeon paramyxovirus type 1 (PPMV-1) strains, which were isolated from infected pigeons in China in 2012 and 2013, were sequenced and analyzed to determine the phylogenetic characteristics of PPMV-1 circulating in pigeons of China in recent years. Furthermore, cross hemagglutination inhibition and cross virus neutralization assays, as well as animal experiments were conducted to determine the antigenicity and pathogenicity of those viruses. Proteolytic cleavage sites (residues 112–117) of the F proteins were identified as the typical virulence motif, 112RRQKR↓F117 for all four PPMV-1 strains investigated.ResultsPhylogenetic analysis based on sequences of complete genomes and F gene revealed that the four PPMV-1 isolates and most of recent isolates in China were highly homologous to European isolates from 1998 to 2011. All those isolates were clustered in one clade of genotype VI NDV, termed as subgroup 4bii f. The R value was calculated based on cross hemagglutination inhibition and cross virus neutralization results, and confirmed antigenic difference of the PPMV-1 strains isolated in 2013 from the LaSota vaccine strain. Several mutations were identified in the surface glycoproteins F and HN, which probably gave rise to those antigenic differences.ConclusionOur result suggested that the PPMV-1 strain prevailing in China in the last decade diverged from a common ancestor and was presumably transmitted from Europe. PPMV-1 isolates displayed obvious antigenic differences from vaccine strain LaSota. Even though PPMV-1 did not cause high mortality in experimental pigeons, the infected pigeons were exhibiting viral shedding for 3 weeks after infection, suggesting PPMV-1 is a potential threat to NDV control worldwide.

Using the reassignment procedure to test object representation in pigeons and people

In four experiments, we evaluated Lea's (1984) reassignment procedure for studying object representation in pigeons (Experiments 1-3) and humans (Experiment 4). In the initial phase of Experiment 1, pigeons were taught to make discriminative button responses to five views of each of four objects. Using the same set of buttons in the second phase, one view of each object was trained to a different button. In the final phase, the four views that had been withheld in the second stage were shown. In Experiment 2, pigeons were initially trained just like the birds in Experiment 1. Then, one view of each object was reassigned to a different button, now using a new set of four response buttons. In Experiment 3, the reassignment paradigm was again tested using the number of pecks to bind together different views of the same object. Across all three experiments, pigeons showed statistically significant generalization of the new response to the non-reassigned views, but such responding was well below that to the reassigned view. In Experiment 4, human participants were studied using the same stimuli and task as the pigeons in Experiment 1. People did strongly generalize the new response to the non-reassigned views. These results indicate that humans, but not pigeons, can employ a unified object representation that they can flexibly map to different responses under the reassignment procedure.

The effect of LPS injections on non-specific immune response in affected pigeons

The aim of the study was to investigate the effect of LPS injections on non-specific mechanisms of immunity in pigeons. On the first day of observation the experimental birds (n=18) were intravenously injected with Escherichia coli LPS (10 microg/kg b.w.), while the control animals (n=6) received in the same way apyrogenic physiological saline. On the second and the third day of the experiment LPS in the same doses was injected again. Four and a half hours after the saline and each pyrogen administration blood samples were collected from the control and experimental pigeons. The total protein, gamma globulin, lysozyme, acute phase protein (Cp, CRP, Tf, ferritin, Alb) and selected trace element (Fe, Cu, Zn) concentrations were investigated. The obtained results showed the increase in the concentration of total protein, Cp, CRP and Tf in endotoxin fever resulting from LPS injection in pigeons. In contrast, the concentration of gamma globulins, ferritin and A1lb were decreased in response to the first LPS injection. However, the consecutive injections of LPS caused a decrease in the concentration of total protein, CRP and Tf. In opposition to those results, a significant rise in the lysozyme and ferritin concentrations was observed. On the other hand, the first LPS injection caused a decline in the iron and zinc concentrations which remaining lower than the control values following repeated administration of LPS. On the contrary, the copper concentration increased successively in response to the next LPS injections.

Cellular immune response of pigeons in the conditions of endotoxin fever and pyrogenic tolerance

The aim of this study was to investigate changes in selected parameters of cellular immune response in the conditions of endotoxin fever and pyrogenic tolerance in pigeons. On the first day of observation the experimental birds (n = 18) were intravenously injected with Escherichia coli LPS at a dose of 10 microg/kg b.w., while the control animals (n = 6) received apyrogenic physiological saline also in the form of injection. On the second and the third day of the experiment LPS was injected additionally at 24 h intervals. Four and a half hours after the saline and pyrogen administration blood samples were collected from the control and experimental pigeons. The following immunological assays were performed: WBC, leucogram and immunophenotyping of lymphocyte subsets in peripheral blood, i.e. CD 3+ (T lymphocytes), CD 4+ (T helper lymphocytes) and CD 8+ (T suppressor/cytotoxic lymphocytes) cells. In the conditions of endotoxin fever (i.e. after the first LPS injection) leucopenia, monocytopenia, heterophilia and eosinophilia were observed. Additionally, the immunophenotyping of peripheral blood lymphocytes indicated an increase in percentage of CD 3+, CD 4+ and CD 8+ cells in response to the single injection of LPS. In contrast, the consecutive injections of LPS, which created a pyrogenic tolerance effect, caused a decrease in WBC value, heteropenia, eosinopenia and lymphocytosis. Moreover, during this state an increase in percentage of CD 3+ and CD 8+ cells was demonstrated in contrast to the percentage of CD 4+ lymphocytes. The general tendencies in cellular immune response of the affected pigeons in the conditions of endotoxin fever and pyrogenic tolerance aim at activation of defence mechanisms against LPS for its prompt elimination from the animal's organism.

Discriminación fina de respuestas en palomas

Normal 0 21 false false false ES-MX X-NONE X-NONE MicrosoftInternetExplorer4 The results of two experiments on fine response discrimination in pigeons are presented. In both experiments pigeons were exposed to a Fixed Consecutive Number (FCN) schedule which required to peck a key for a fixed number of times and then visit the food hooper. Experiment 1 used two schedules (FCN 4 and FCN 8) and assessed the effects of their presentation order. The results showed that pigeons that were first trained on a FCN 4 schedule and then switched to a FCN 8 showed a better performance than pigeons exposed to the reversed sequence of conditions. The purpose of Experiment 2 was to test, using a FCN schedule with fixed upper and lower response requirements, a shaping procedure which consisted in gradually reducing the upper and the lower limits to the exact number of responses; pigeons were changed to a higher or lower FCN schedule. Results showed that response discrimination was better in the subjects that werw changed to a high FCN schedule. These data support the thesis that pigeons discriminate in a differential way among adjacent quantities of elements.

The Role of the Magnetite-Based Receptors in the Beak in Pigeon Homing

Magnetite-containing structures in the upper beak of birds have been described as putative magnetoreceptors [1-4], but so far, all positive evidence indicating their influence on behavior has come from laboratory studies using rather unnatural stimuli (e.g., [5-7]). Here, we demonstrate these receptors' possible role in a natural situation: we released pigeons with these receptors deactivated by a local anesthetic within and outside a magnetic anomaly, together with untreated control birds. Within the anomaly, the untreated birds showed unusually long vanishing intervals and scattered bearings, indicating confusion by the anomalous magnetic conditions. Anesthesia of the beak suppressed this adverse effect. Outside the anomaly, in contrast, the treatment had little effect. These findings indicate that the receptors in the beak mediate magnetic "map" information and that this information is normally included in the navigational process yet can be replaced by nonmagnetic factors at most sites.

Pigeons can discriminate group mates from strangers using the concept of familiarity

It is widely accepted that group-living animals alter their behaviour towards a conspecific depending on whether it is known or unknown. To distinguish between group members and strangers in an efficient way, it would be adaptive for an animal to categorize conspecifics on the basis of familiarity. We investigated whether pigeons, Columba livia , are able to learn this categorization in a concept-like manner when trained with 2D images of conspecifics. Two of the six experimental pigeons were able correctly to classify test photographs of aviary mates which they had never seen as photographic stimuli before. Control animals, which had no real-life experience of the pictured conspecifics, all failed. This is a cognitively demanding task; not only are there no consistent visual features among group members, but photographic stimuli also present a much degraded version of the depicted pigeons. Further tests revealed that the familiarity concept could be transferred to nonconspecifics and that 24 h of exposure was enough for another pigeon to be classed as familiar. In sum, the findings show that pigeons (1) interpreted computer stimuli as representations of real entities, (2) possessed the ability to form a concept of familiarity and (3) were able to distinguish between social partners and strangers in nature.

QUANTITATIVE ULTRASOUND, MAGNETIC RESONANCE IMAGING, AND HISTOLOGIC IMAGE ANALYSIS OF HEPATIC IRON ACCUMULATION IN PIGEONS (COLUMBIA LIVIA)

Iron overload was induced by iron dextran i.v. in clinically healthy adult pigeons, Columbia livia, (n = 8). Hemosiderosis was induced in all treated birds. Two control pigeons received no iron injections. Pigeons did not show clinical signs of iron overload during the 6-wk study. Ultrasound examination of the liver in the pigeons receiving iron dextran was performed on days 0, 13, 28, and 42. No ultrasound images were collected on the control pigeons. Magnetic resonance imaging was performed on days 0, 13, 28, and 42 on all study pigeons and imaging sequences were collected in three different imaging formats: T1, T2, and gradient-recalled echo (GRE). Surgical liver biopsies were performed on pigeons receiving iron dextran on days 2, 16, and 45 (at necropsy). A single liver sample was collected at necropsy from the control birds. Histologic examination, quantitative image analysis, and tissue iron analysis by thin-layer chromatography were performed on each liver sample and compared to the imaging studies. Although hemosiderosis was confirmed histologically in each experimental pigeon, no significant change in pixel intensity of the ultrasound images was seen at any point in the study. Signal intensity, in all magnetic resonance imaging formats, significantly decreased in a linear fashion as the accumulation of iron increased.

The discrimination of natural movement by budgerigars (Melopsittacus undulates) and pigeons (Columba livia).

Three experiments examined the ability of birds to discriminate between the actions of walking forwards and backwards as demonstrated by video clips of a human walking a dog. Experiment 1 revealed that budgerigars (Melopsittacus undulates) could discriminate between these actions when the demonstrators moved consistently from left to right. Test trials then revealed that the discrimination transferred, without additional training, to clips of the demonstrators moving from right to left. Experiment 2 replicated the findings from Experiment 1 except that the demonstrators walked as if on a treadmill in the center of the display screen. The results from the first 2 experiments were replicated with pigeons in Experiment 3. The results cannot be explained if it is assumed that animals rely on static cues, such as those derived from individual postures, in order to discriminate between the actions of another animal. Instead, this type of discrimination appears to be controlled by dynamic cues derived from changes in the posture of the demonstrators.

Isolation and characterization of a coronavirus from pigeons with pancreatitis

To identify and partially characterize a coronaviruslike virus isolated from naturally infected pigeons. 50 specific pathogen-free (SPF) embryonated chicken eggs, 30 White Leghorn SPF chickens, and 12 clinically normal pigeons. Pancreatic tissue specimens from sick pigeons were inoculated into SPF embryonated chicken eggs for viral isolation and investigation of morphologic and hemagglutinating properties of the isolate, called PSH050513. Furthermore, virulence studies in SPF chickens and experimental pigeons were performed. The spike (S) glycoprotein gene of PSH050513 was further sequenced and analyzed. PSH050513 was isolated and identified from the experimentally infected pigeons by a routine method, which was in accordance with Koch's postulates. The complete S protein (1,167 amino acids) was compared with published S protein sequences of other avian and mammalian coronaviruses. A high degree of sequence identity (79.3% to 99.6%) was observed between the S protein sequence of PSH050513 and published sequences of avian infectious bronchitis virus (IBV); only limited identity (< 37.8%) was observed with turkey coronavirus and mammalian coronaviruses. Furthermore, when the virus was inoculated into SPF chickens, pancreatitis developed. PSH050513 has been tentatively identified as a novel member of group 3 coronaviruses that have close genetic relationships with IBV strains.

Classical tone-shock conditioning induces zenk expression in the pigeon (Columba livia) hippocampus.

The hippocampus is involved in fear conditioning, although the molecular events underlying this function are still under investigation. The authors analyzed the expression of the Zenk proto-oncogene product within the pigeon (Columba livia) hippocampus after training with a classical aversive conditioning protocol using tone-shock associations. Control groups were trained with shock or tone alone or were only exposed to the experimental chamber and manipulated. Experimental pigeons showed significant increases of Zenk expression in the ventromedial region of the hippocampus, whereas both the experimental and shock groups had increased Zenk expression in the dorsal region. The expression of Zenk in specific neuronal populations within the pigeon hippocampus may be indicative of plasticity-associated aversive classical conditioning.

Superconditioning from a reduced reinforcer.

In four autoshaping experiments pigeons received conditioned inhibition training of the form A++, AB-, where ++ is a strong reinforcer and - is nonreinforcement. Subsequent AB+ training, in which + is a moderate reinforcer, resulted in enhanced conditioning of A, relative to an A stimulus receiving no treatment, one receiving A+ treatment, and one receiving A++ treatment. This enhancement of conditioning to A constitutes a demonstration of "superconditioning". The presence of the inhibitory B sufficiently enhanced the reinforcing power of the moderate reinforcer (+) that it was able to further increase the excitation controlled by A. This occurred even though A had previously been paired with a stronger reinforcer (++). Superconditioning was also observed when A and B were extinguished prior to treatment with + or were originally neutral stimuli followed by + in the presence of an inhibitor trained elsewhere.

Monitoring of pigeon paramyxovirus type-1 in organs of pigeons naturally infected with Salmonella Typhimurium

An experimental pigeon paramyxovirus (pPMV-1) infection was followed by reverse transcription-nested polymerase chain reaction for 31 days after infection, in 16 organs of inoculated or contact pigeons naturallyinfected with Salmonella Typhimurium. With two exceptions, both groups presented similar results. Typical nervous signs and a green diarrhoea were observed. The spread of pPMV-1 was relatively quick, all organs beinglargely positive at 4 days after inoculation or contact. The lung, spleen, caecal tonsils, kidneys and brain, for which almost all tested samples remained positive during most of the experiment, seemed to be the principal targets for virus persistence. However, the virus was significantly recovered later in the brain parts and for longer in the trachea of the contact pigeons than of the inoculated ones.

Operant discriminative learning and evidence of subtelencephalic plastic changes after long-term detelencephalation in pigeons.

We analyzed operant discrimination in detelencephalated pigeons and neuroanatomical substrates after long-term detelencephalation. In Experiment I, experimental pigeons with massive telencephalic ablation and control pigeons were conditioned to key peck for food. Successive discrimination was made under alternating red (variable-ratio reinforcement) and yellow (extinction) lights in one key of the chamber. These relations were interchanged during reversal discrimination. The sessions were run until steady-state rates were achieved. Experiment II analyzed the morphology of the nucleus rotundus and optic tectum in long-term detelencephalated and control birds, using a Klüver-Barrera staining and image analyzer system. Detelencephalated birds had more training sessions for response shaping and steady-state behavior (p<0.001), higher red key peck rates during discrimination (p<0.01), and reversal discrimination indexes around 0.50. Morphometric analysis revealed a decreased number of neurons and increased vascularity, associated with increases in the perimeter (p<0.001) in the nucleus rotundus. In the optic tectum, increases in the perimeter (p<0.05) associated with disorganization in the layers arrangement were seen. The data indicate that telencephalic systems might have an essential function in reversal operant discrimination learning. The structural characteristics of subtelencephalic systems after long-term detelencephalation evidence plastic changes that might be related to functional mechanisms of learning and neural plasticity in pigeons.