Experimental infection of domestic turkeys with lymphoproliferative disease virus of North American origin.

Lymphoproliferative disease virus (LPDV) was first documented in wild turkeys in North America in 2009. LPDV infection is often subclinical but can manifest as lymphoid proliferation or round cell neoplasia. Despite high prevalence across many sampled areas corresponding to declining populations of wild turkeys, knowledge regarding LPDV pathogenesis, risk factors for disease development, and associated impacts on population dynamics are unknown. To understand transmission, viral shedding, and tissue tropism, we inoculated 21 domestic turkeys via the oral cavity, crop, nasal cavity, subcutis, or coelomic cavity. For 12 weeks, oropharyngeal swabs, cloacal swabs, and whole blood were collected weekly. At 1 week postinoculation, 3 turkeys (3/21; 14%) had detectable LPDV proviral DNA in blood by polymerase chain reaction, and 10 developed DNAemia (50%; 10/20) by 12 weeks. LPDV proviral DNA was intermittently detected in oropharyngeal and cloacal swabs. Splenomegaly was the most consistent gross finding in DNAemic birds (8/11; 73%). Lymphoid hyperplasia in the spleen was the most significant microscopic finding (9/11; 82%). Three turkeys (3/11; 27%) developed round cell neoplasia characterized by sheets of pleomorphic, round to polygonal cells in the adrenal gland, bone marrow, skin, small intestine, and/or spleen. LPDV was detected in the spleen and bone marrow from all turkeys with DNAemia and all neoplasms. Our study establishes that infection and disease with North American LPDV from wild turkeys can be experimentally reproduced in domestic turkeys, laying the groundwork for future investigations into LPDV pathogenesis, development of diagnostic techniques, and understanding the impacts of LPDV on wild turkey populations.

Sequencing and characterization of complete mitogenome DNA of worldwide turkey (Meleagris gallopavo) populations.

The history of turkey (Meleagris gallopavo) domestication can be traced back to the period between 700 and 200 BC in Mexico. This process involved multiple contributors and resulted in the development of modern local turkey breeds. This research investigates the complete mitochondrial diversity across a diverse range of local turkeys. Seventy-three turkeys were sampled from various populations, including autochthonous Italian breeds, an American breed (Narragansett), as well as wild turkeys from the USA and Mexico. The mitochondrial DNA (mtDNA) was employed as a powerful tool for biodiversity and breed phylogeny investigation. An analysis of the entire mtDNA was conducted to identify breed-specific unique traits, mitochondrial-specific characteristics, and the phylogenetic relationship among turkey populations. A total of 44 polymorphic sites were identified. Brianzolo and Narragansett birds were characterized as genetically homogeneous populations. Thirty-two different haplotypes were identified when our samples were compared with mtDNA D-loop of 96 online available turkeys from various geographical countries. H1 and H2, differing for one mutation, were the most abundant, comprising 132 of the 185 sequences. H1 included samples coming from every region, while H2 was predominantly characterized by Italian samples. USA and Mexican samples appear to be more variable in their mtDNA than the other populations.

Susceptibility of wild turkeys (Meleagris gallopavo) to experimental West Nile virus infection.

Since the introduction of West Nile virus (WNV) to North America in 1999, WNV is estimated to have contributed to population-level declines in numerous avian species. However, the potential impacts of this virus on many free-ranging upland game bird species, including the wild turkey (Meleagris gallopavo), which is undergoing regional population declines, remain unknown. Herein, two age groups (∼5 to 6 weeks and ∼15 to 16 weeks post-hatch) of juvenile wild turkeys were subcutaneously inoculated with WNV, sampled daily from 1 to 7 days post-inoculation (dpi), and euthanized on 14 dpi. No clinical signs and minimal gross lesions were attributable to WNV infection. Peak viraemia titres were similar between age groups (<101.7 to 104.6 plaque-forming units [PFU]/ml), but the duration of viraemia was longer in the old group (3-4 days) than in the young group (0-3 days). Intermittent oral and/or cloacal viral shedding from 2 to 7 dpi was detected in both age groups. No infectious virus was detected in the heart, brain, kidney, skeletal muscle, spleen, and feathers from WNV-inoculated turkeys euthanized on 14 dpi. All WNV-inoculated birds seroconverted by 14 dpi, as well as two co-housed sham-inoculated birds. The most consistent microscopic lesions among all WNV-inoculated birds were mild lymphoplasmacytic myocarditis and encephalitis. Minimal immunohistochemical labelling was detected in tissues in addition to scant macrophages within the blood, spleen, and bone marrow. These data suggest WNV is unlikely to pose a significant risk to wild turkey populations, although the possibility remains that WNV may indirectly decrease fitness or predispose wild turkeys to other health stressors.RESEARCH HIGHLIGHTS Clinical disease was not observed in wild turkeys experimentally infected with WNV.Pathology attributed to WNV was mild and included brain and heart inflammation.Viraemias suggest WNV-infected wild turkeys do not play a role in WNV transmission.No age-associated differences in WNV clinical disease or pathology were observed.

Plasticity of the gastrocnemius elastic system in response to decreased work and power demand during growth.

Elastic energy storage and release can enhance performance that would otherwise be limited by the force-velocity constraints of muscle. Although functional influence of a biological spring depends on tuning between components of an elastic system (the muscle, spring-driven mass and lever system), we do not know whether elastic systems systematically adapt to functional demand. To test whether altering work and power generation during maturation alters the morphology of an elastic system, we prevented growing guinea fowl (Numida meleagris) from jumping. We compared the jump performance of our treatment group at maturity with that of controls and measured the morphology of the gastrocnemius elastic system. We found that restricted birds jumped with lower jump power and work, yet there were no significant between-group differences in the components of the elastic system. Further, subject-specific models revealed no difference in energy storage capacity between groups, though energy storage was most sensitive to variations in muscle properties (most significantly operating length and least dependent on tendon stiffness). We conclude that the gastrocnemius elastic system in the guinea fowl displays little to no plastic response to decreased demand during growth and hypothesize that neural plasticity may explain performance variation.

Extreme climate events limit northern range expansion of wild turkeys.

For species inhabiting areas at the limit of their environmental tolerance, extreme events often drive population persistence. However, because extreme events are uncommon, their effects on population dynamics of expanding species are poorly known. We examined how extreme climate events in winter and summer affected three populations of wild turkeys occupying a natural climate gradient at the northern edge of their range. First, we examined the mechanism by which vital rates affect the population growth rate. Second, we developed a climate-dependent structured population model. Finally, by linking this population model to IPCC-class climate projections, we projected wild turkey population abundance in response to the frequency of extreme snow events by 2100 for the northernmost population. We showed that the population dynamics of the three populations is driven through different pathways expected from the theory of invading population dynamics; that those populations were mainly limited by heavy snow that decreases winter survival by restraining food access; and that a population of immigrant is projected to decline at the northern species range. This study exemplifies how extreme events affect population dynamics and range expansion of temperate species at the northern edge of the distribution.

Outbreak of avian mycobacteriosis in a commercial turkey breeder flock.

Avian mycobacteriosis (AM) is a chronic and contagious disease of pet birds, captive exotic, wild and domestic fowl, and mammals. Mycobacterium avium subsp. avium is the most common cause of AM in poultry. For the first time, we report a chronic outbreak of AM in an Iranian breeder flock of 250 45-week-old turkeys (Meleagris gallopavo) with a morbidity and mortality rate of 91.6% and 80%, respectively. A well-defined clinical feature of the outbreak included a progressive weight loss, decreased egg production, listlessness, and lameness. Tuberculous nodules were seen on liver, spleen, ovary, and ribs. Granulomatous inflammation and acid-fast bacilli were confirmed by using Ziehl-Neelsen method on hepatic lesions. M. avium subsp. avium was identified by polymerase chain reaction techniques based on the presence of 16S ribosomal RNA gene and insertion elements IS1245 and IS901. In this report, we not only describe the epidemiological, pathological, and molecular characteristics of the outbreak in detail, but we also discuss multiple factors influencing the introduction and development of AM critically. In this case, wild feral pigeons might have been the source of infection, but further molecular-epidemiology studies are needed to understand the role of wild birds in the persistence and transmission of Mycobacterium.RESEARCH HIGHLIGHTS First report of avian mycobacteriosis in an Iranian commercial turkey flock is described in detail.Risk factors intrinsic to the bird and mycobacteria, as well as extrinsic factors influencing the introduction and development of avian mycobacteriosis in birds, are critically discussed.

Thermal refuge affects space use and movement of a large-bodied galliform.

Temperature affects every organism on Earth and has been argued to be one of the most critical factors influencing organisms' ecology and evolution. Most organisms are susceptible to landscape temperature ranges that exceed their thermal tolerance. As a result, the distribution of landscape features that mitigate thermal extremes can affect movement and space use of organisms. Using Rio Grande wild turkey (Meleagris gallopavo intermedia) as a model species, we measured black bulb temperature throughout the diurnal period and identified vegetation characteristics at wild turkey locations and random landscape locations. We observed that the thermal landscape was highly heterogeneous with temperature varying up to 52 °C at a given ambient temperature. Vegetation type strongly influenced temperature across space during daily peak heating, with taller vegetation types (woody vegetation >2 m) having mean temperatures up to 8.95 °C cooler than the remainder of the landscape. However, these cooler vegetation types were uncommon, only accounting for 8.2% of the landscape. Despite the rarity of tall woody cover, wild turkey showed strong selection for this vegetation type particularly during peak daily heating with 74.9% of locations within 18 m of tree cover. Not only did wild turkey alter space use across time relative to temperature variation, but they also altered movement. We found that on the hottest days (≥35 °C), wild turkeys decreased movement by three fold during peak heating, while movement on cooler days (<30 °C) was uniform. Collectively, our data provide evidence that space use and movement for large avian species can be influenced by the thermal environment, and that the thermal environment is an important component of habitat for a species.

Association of the whale shark Rhincodon typus with the cannonball jellyfish Stomolophus meleagris.

This study describes the first record of the whale shark Rhincodon typus association with the cannonball jellyfish Stomolophus meleagris in the Gulf of California, Mexico. Whale sharks were observed swimming and feeding among swarms of jellyfish, suggesting competition and predatory behaviour given the overlap in food preferences between both species. This finding is relevant because of the species-wide distribution and the importance of these interactions, which should be considered in conservation strategies of R. typus and management of cannonball jellyfish fisheries.

Fatal Pulmonary Edema in a Child After Jellyfish Stings in Korea.

Jellyfish have been increasing at a global scale in recent years. These blooms not only have deleterious effects on marine ecosystems, they also increase the risk of jellyfish stings and accompanying envenomation. Here, we report a fatal case of pulmonary edema caused by jellyfish envenomation in a child in Korea. The patient died 4 h after envenomation despite cardiopulmonary resuscitation. Nemopilema nomurai was the suspected species of jellyfish encountered by the patient, although we are unable to confirm this. With this case report, we aim to inform on the serious issue of toxicity associated with jellyfish species that bloom mainly along Korean, east Chinese, and Japanese shores and to discuss appropriate first aid methods in case of jellyfish stings.

Avoiding Missing Data Biases in Phylogenomic Inference: An Empirical Study in the Landfowl (Aves: Galliformes).

Production of massive DNA sequence data sets is transforming phylogenetic inference, but best practices for analyzing such data sets are not well established. One uncertainty is robustness to missing data, particularly in coalescent frameworks. To understand the effects of increasing matrix size and loci at the cost of increasing missing data, we produced a 90 taxon, 2.2 megabase, 4,800 locus sequence matrix of landfowl using target capture of ultraconserved elements. We then compared phylogenies estimated with concatenated maximum likelihood, quartet-based methods executed on concatenated matrices and gene tree reconciliation methods, across five thresholds of missing data. Results of maximum likelihood and quartet analyses were similar, well resolved, and demonstrated increasing support with increasing matrix size and sparseness. Conversely, gene tree reconciliation produced unexpected relationships when we included all informative loci, with certain taxa placed toward the root compared with other approaches. Inspection of these taxa identified a prevalence of short average contigs, which potentially biased gene tree inference and caused erroneous results in gene tree reconciliation. This suggests that the more problematic missing data in gene tree-based analyses are partial sequences rather than entire missing sequences from locus alignments. Limiting gene tree reconciliation to the most informative loci solved this problem, producing well-supported topologies congruent with concatenation and quartet methods. Collectively, our analyses provide a well-resolved phylogeny of landfowl, including strong support for previously problematic relationships such as those among junglefowl (Gallus), and clarify the position of two enigmatic galliform genera (Lerwa, Melanoperdix) not sampled in previous molecular phylogenetic studies.

Characterization of three pyranose dehydrogenase isoforms from the litter-decomposing basidiomycete Leucoagaricus meleagris (syn. Agaricus meleagris).

Multigenicity is commonly found in fungal enzyme systems, with the purpose of functional compensation upon deficiency of one of its members or leading to enzyme isoforms with new functionalities through gene diversification. Three genes of the flavin-dependent glucose-methanol-choline (GMC) oxidoreductase pyranose dehydrogenase (AmPDH) were previously identified in the litter-degrading fungus Agaricus (Leucoagaricus) meleagris, of which only AmPDH1 was successfully expressed and characterized. The aim of this work was to study the biophysical and biochemical properties of AmPDH2 and AmPDH3 and compare them with those of AmPDH1. AmPDH1, AmPDH2 and AmPDH3 showed negligible oxygen reactivity and possess a covalently tethered FAD cofactor. All three isoforms can oxidise a range of different monosaccarides and oligosaccharides including glucose, mannose, galactose and xylose, which are the main constituent sugars of cellulose and hemicelluloses, and judging from the apparent steady-state kinetics determined for these sugars, the three isoforms do not show significant differences pertaining to their reaction with sugar substrates. They oxidize glucose both at C2 and C3 and upon prolonged reaction C2 and C3 double-oxidized glucose is obtained, confirming that the A. meleagris genes pdh2 (AY753308.1) and pdh3 (DQ117577.1) indeed encode CAZy class AA3_2 pyranose dehydrogenases. While reactivity with electron donor substrates was comparable for the three AmPDH isoforms, their kinetic properties differed significantly for the model electron acceptor substrates tested, a radical (the 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulphonic acid] cation radical), a quinone (benzoquinone) and a complexed iron ion (the ferricenium ion). Thus, a possible explanation for this PDH multiplicity in A. meleagris could be that different isoforms react preferentially with structurally different electron acceptors in vivo.

Gearing effects of the patella (knee extensor muscle sesamoid) of the helmeted guineafowl during terrestrial locomotion.

Human patellae (kneecaps) are thought to act as gears, altering the mechanical advantage of knee extensor muscles during running. Similar sesamoids have evolved in the knee extensor tendon independently in birds, but it is unknown if these also affect the mechanical advantage of knee extensors. Here, we examine the mechanics of the patellofemoral joint in the helmeted guineafowl Numida meleagris using a method based on muscle and tendon moment arms taken about the patella's rotation centre around the distal femur. Moment arms were estimated from a computer model representing hindlimb anatomy, using hip, knee and patellar kinematics acquired via marker-based biplanar fluoroscopy from a subject running at 1.6 ms-1 on a treadmill. Our results support the inference that the patella of Numida does alter knee extensor leverage during running, but with a mechanical advantage generally greater than that seen in humans, implying relatively greater extension force but relatively lesser extension velocity.

Impact of black soldier fly larval meal on growth performance, apparent digestibility, haematological and blood chemistry indices of guinea fowl starter keets under tropical conditions.

In order to assess the impact of larval meal on guinea fowl, six iso-caloric and iso-nitrogenous diets were fed to day-old-keets ad libitum till 8 weeks of age. Water was also freely provided. The fishmeal (FM) component of the experimental diets was replaced with black soldier fly larval meal (BSFLM) in the following percentage ratios of 0-100%. Results showed that body weight gain significantly (P < 0.05) increased in all the BSFLM treatment groups compared to the control group. The final body weight of the birds at age 8 weeks differed significantly (P < 0.001). Dry matter intake varied (P < 0.001) slightly among the birds but never affected (P > 0.05) ME intake and faecal output as well as weight changes of the keets. Digestibility of dry matter and energy were not affected (P > 0.05) by the differences in diet. Organ and haematopoietic integrity were assured regardless of the protein types used as well as levels of inclusion. The results suggest that the replacement of fishmeal with BSFLM in so far as the economics of production is concerned could result in reduced feed cost for starter guinea keet judging from diets that contained 60-100% BSFLM.

PHARMACOKINETIC EVALUATION OF A LONG-ACTING FENTANYL SOLUTION AFTER TRANSDERMAL ADMINISTRATION IN HELMETED GUINEAFOWL (NUMIDA MELEAGRIS).

The objective of this study was to investigate the pharmacokinetics of a long-acting fentanyl solution in helmeted guineafowl ( Numida meleagris ) after transdermal administration. Twenty-one guineafowl received a single administration of 5 mg/kg of fentanyl transdermal solution. No adverse effects on behavior were appreciated. Plasma fentanyl concentrations were determined by liquid chromatography-mass spectrometry analysis of protein-precipitated samples. Mean maximum plasma concentration was 228.8 ng/ml at 4 hr. The mean plasma terminal half-life was 33.2 hr. At 168 hr the mean plasma concentration was 1.3 ng/ml. A single topical dose of 5 mg/kg appears to be safe for use in this species and maintained plasma concentrations above those reported to be analgesic in dogs for at least 7 days.

Measurement of Tear Production and Intraocular Pressure in Healthy Captive Helmeted Guinea Fowl ( Numida meleagris ).

We establish reference values of tear production by the phenol red thread test (PRTT) and intraocular pressure (IOP) by rebound tonometry in helmeted guinea fowl ( Numida meleagris ). Aqueous tear production and IOP were measured in 44 (22 males, 22 females) clinically normal captive helmeted guinea fowl. Birds were gently physically restrained in the sitting position without any pressure to the head or neck. In each bird, aqueous tear production was measured by placing phenol red threads in the superior conjunctival fornix, and IOP was measured by using a Tonovet rebound tonometer. Overall mean ± standard deviation (SD) values of PRTT and IOP of all eyes were 16.5 ± 1.3 mm/15 s (ranging from 14-18 mm/15 s) and 9.1 ± 0.9 mm Hg (ranging from 7-10 mm Hg), respectively. No significant differences were found in IOP or PRTT between males and females (P = .76; P = .83, respectively) or between the left and right eyes (P = .34 and .66, respectively) in the guinea fowl. Results of this study may be beneficial for the diagnosis and therapy of keratoconjunctivitis sicca, glaucoma, and uveitis in helmeted guinea fowl.

How do treadmill speed and terrain visibility influence neuromuscular control of guinea fowl locomotion?

Locomotor control mechanisms must flexibly adapt to both anticipated and unexpected terrain changes to maintain movement and avoid a fall. Recent studies revealed that ground birds alter movement in advance of overground obstacles, but not treadmill obstacles, suggesting context-dependent shifts in the use of anticipatory control. We hypothesized that differences between overground and treadmill obstacle negotiation relate to differences in visual sensory information, which influence the ability to execute anticipatory manoeuvres. We explored two possible explanations: (1) previous treadmill obstacles may have been visually imperceptible, as they were low contrast to the tread, and (2) treadmill obstacles are visible for a shorter time compared with runway obstacles, limiting time available for visuomotor adjustments. To investigate these factors, we measured electromyographic activity in eight hindlimb muscles of the guinea fowl (Numida meleagris, N=6) during treadmill locomotion at two speeds (0.7 and 1.3 m s(-1)) and three terrain conditions at each speed: (i) level, (ii) repeated 5 cm low-contrast obstacles (<10% contrast, black/black), and (iii) repeated 5 cm high-contrast obstacles (>90% contrast, black/white). We hypothesized that anticipatory changes in muscle activity would be higher for (1) high-contrast obstacles and (2) the slower treadmill speed, when obstacle viewing time is longer. We found that treadmill speed significantly influenced obstacle negotiation strategy, but obstacle contrast did not. At the slower speed, we observed earlier and larger anticipatory increases in muscle activity and shifts in kinematic timing. We discuss possible visuomotor explanations for the observed context-dependent use of anticipatory strategies.

Guineafowl with a twist: asymmetric limb control in steady bipedal locomotion.

In avian bipeds performing steady locomotion, right and left limbs are typically assumed to act out of phase, but with little kinematic disparity. However, outwardly appearing steadiness may harbor previously unrecognized asymmetries. Here, we present marker-based XROMM data showing that guineafowl on a treadmill routinely yaw away from their direction of travel using asymmetrical limb kinematics. Variation is most strongly reflected at the hip joints, where patterns of femoral long-axis rotation closely correlate to degree of yaw divergence. As yaw deviations increase, hip long-axis rotation angles undergo larger excursions and shift from biphasic to monophasic patterns. At large yaw angles, the alternately striding limbs exhibit synchronous external and internal femoral rotations of substantial magnitude. Hip coordination patterns resembling those used during sidestep maneuvers allow birds to asymmetrically modulate their mediolateral limb trajectories and thereby advance using a range of body orientations.

Mitochondrial DNA variation of Nigerian domestic helmeted guinea fowl.

We analyzed genetic diversity of 215 mitochondrial DNA (mtDNA) D-loop sequences from seven populations of domesticated helmeted guinea fowl (Numida meleagris) in Nigeria and compared that with results of samples collected in Kenya (n = 4) and China (n = 22). In total, 241 sequences were assigned to 22 distinct haplotypes. Haplotype diversity in Nigeria was 0.693 ± 0.022. The network grouped most matrilines into two main haplogroups: A and B. There was an absence of a geographic signal, and two haplotypes dominated across all locations with the exception of the Kebbi population in the northwest of the country; AMOVA also confirmed this observation (FST  = 0.035). The low genetic diversity may be a result of recent domestication, whereas the lack of maternal genetic structure likely suggests the extensive genetic intermixing within the country. Additionally, the differentiation of the Kebbi population may be due to a certain demographic history and/or artificial selection that shaped its haplotype profile. The current data do not permit us to make further conclusions; therefore, more research evidence from genetics and archaeology is still required.

DIAGNOSING LYMPHOPROLIFERATIVE DISEASE VIRUS IN LIVE WILD TURKEYS (MELEAGRIS GALLOPAVO) USING WHOLE BLOOD.

Lymphoproliferative disease virus (LPDV) is a retrovirus that infects wild and domestic turkeys ( Meleagris gallopavo ). The first cases of LPDV in the United States were diagnosed in 2009, and subsequent surveillance has revealed the virus to be widespread in wild turkey populations throughout the eastern half of the country. More research is needed to determine whether LPDV is having a negative effect on turkey populations, but progress has been impeded by the lack of a simple method for diagnosing the virus in living birds. Infected animals may appear asymptomatic, and diagnostics currently rely on tissue or bone marrow, which can be difficult to obtain. This study investigated the reliability of polymerase chain reaction (PCR) to detect LPDV in whole blood, compared with previous methods using buffy coat (concentrated white blood cells) and bone marrow. Paired samples of whole blood and buffy coat were collected from 137 live turkeys and paired samples of whole blood and bone marrow were collected from 32 turkeys postmortem. Compared with buffy coat, whole blood had 97% sensitivity and 100% specificity. When compared with bone marrow, whole blood had 100% sensitivity and 89% specificity. Both comparisons had a high degree of agreement using Cohen's kappa statistic. Based on these results, PCR of whole blood provides detection of LPDV in living birds that is on par with both buffy coat and bone marrow.

Use of Deslorelin Acetate Implants to Mitigate Aggression in Two Adult Male Domestic Turkeys (Meleagris gallopavo) and Correlating Plasma Testosterone Concentrations.

Two adult, male domestic turkeys were treated with implants of deslorelin acetate, a gonadotropin-releasing hormone agonist, to reduce intermale aggression and aggression directed toward the animal care team at a zoologic institution. The turkeys were manually restrained and either two 4.7-mg or two 9.4-mg implants were placed within the pectoral musculature on 3 occasions over the course of approximately 1.5 years. Plasma testosterone concentrations were measured by radioimmunoassay every 2 weeks for the first month after a new implant placement and then monthly thereafter. Testosterone concentrations remained low and aggressive behavior was decreased for a period of several months after implant placement. At necropsy of both birds, no adverse gross or histologic lesions were noted at the implantation sites in the pectoral musculature or within the gonadal tissue. Deslorelin acetate implants are a treatment modality to consider for mitigation of aggression in male domestic turkeys.