Gallinae Research Articles

Description of the mitochondrial genomes of Sichuan Tetrastes sewerzowi (Galliformes: Tetraonidae) and phylogenetic relationship.

The Chinese Grouse (Tetrastes sewerzowi), a rare endemic bird in China, belongs to the Galliformes order and Tetraonidae family. Despite extensive research, subspecies classification remains inadequate, especially in Pingwu, Sichuan. This study sequenced the mitochondrial genome of T. sewerzowi in Wanglang Nature Reserve, Sichuan, analyzed its structural features, and reconstructed phylogenetic relationships within Tetraonidae. The results indicate that the high conservation in mitochondrial genome structure and sequence between the T. sewerzowi from Wanglang, Sichuan and Lianhuashan, Gansu indicates that they may belong to the same subspecies. Furthermore, we observed significant differences in the length of the mitochondrial control region between T. sewerzowi and Tetrastes bonasia. Based on the phylogenetic tree constructed using a comprehensive mitochondrial dataset, we propose the reclassification of the Hazel Grouse genus into two independent genera: Tetrastes and Bonasa. This study is the first to sequence the mitochondrial genome of T. sewerzowi from Sichuan and compare it with populations from Gansu, providing important insights into the distribution pattern of T. sewerzowi subspecies and facilitating the formulation of effective conservation strategies.

Trichomonad Disease in Wild Turkeys (Meleagris gallopavo): Pathology and Molecular Characterization of Histomonas, Tetratrichomonas, Tritrichomonas, and Simplicimonas spp.

The Wild Turkey (Meleagris gallopavo) is a geographically widespread, popular game bird and conservation icon in North America. Following successful reestablishment in parts of the US and Canada, regional declines have fueled population health concerns; therefore, understanding mortality causes and spatiotemporal patterns of disease is important to uncover potential ongoing and future health risks. Histomonosis, caused by the trichomonad Histomonas meleagridis, is a well-established and potentially fatal disease in Wild Turkeys; however, its prevalence and potential population health impacts remain poorly understood. Moreover, molecular tools recently have allowed for the detection of additional trichomonads that similarly can cause fatal disease in Wild Turkeys. We describe and compare disease due to H. meleagridis with that of Tetratrichomonas gallinarum, Tritrichomonas sp., and Simplicimonas sp. in Wild Turkeys in the southeastern US. Among 857 Wild Turkeys evaluated postmortem from 2002 to 2023, 34 (4.0%) were diagnosed with trichomonad disease, often assumed to be histomonosis prior to molecular testing. However, among 25 debilitating to fatal trichomonad disease cases for which etiologies were confirmed by PCR from 2015 to 2023, H. meleagridis was detected in 16/25 (64.0%), T. gallinarum in 6/25 (24.0%), Tritrichomonas sp. in 2/25 (8.0%) and Simplicimonas sp. in 1/25 (4.0%). These turkeys had similar clinical manifestations, and although lesion patterns varied to some extent, liver and/or intestinal tract was most commonly affected. Coinfections were common among all turkeys with trichomonad disease from 2015 to 2023 (21/25, 84.0%) and included viruses (lymphoproliferative disease virus, avian poxvirus), bacteria (Streptococcus gallolyticus, Listeria monocytogenes, Escherichia coli), and other protozoa (Sarcocystis sp., Haemoproteus sp.). Our results highlight the importance of molecular diagnostic testing in determining etiologies of trichomonad disease in Wild Turkeys. Further evaluation of the epidemiology and pathogenesis of trichomonad disease and its varied etiologies in Wild Turkeys and other birds is warranted to better understand risk factors and potential health impacts.

Utilizing Flaxseed as an Antimicrobial Alternative in Chickens: Integrative Review for Salmonella enterica and Eimeria

This review provides an integrative framework for understanding flaxseed (Linum utassitissimum) as an antimicrobial alternative for poultry production. We begin by familiarizing the reader with the global legislation of antibiotics in animal husbandry; highlighting gaps and current issues for Salmonella enterica (S. enterica) and Eimeria (coccidiosis-inducing). We then discuss the natural, symbiotic characteristics of the Galliformes order (chicken-like birds) and Linum (the flaxes). The key immunological themes in this review include: (i) flaxseed’s regulation of innate and adaptive immunity in chickens, (ii) flaxseed’s ability to accelerate chicken recovery from infection with S. enterica and Eimeria, and (iii) flaxseed’s strengthening of immunity via vitamin B6 antagonism. Research indicates that whole flaxseed increases adaptive immune capacity by augmenting cecal Bacteroides and short-chain fatty acids while also attenuating the heterophil to lymphocyte ratio in chickens. Moreover, flaxseed accelerates chicken recovery from infection with Salmonella Enteritidis or Eimeria tenella; however, future work is needed to better understand (i) defatted flaxseed’s superior performance against Eimeria species and (ii) Eimeria maxima’s resilience against whole flaxseed. In the context of vitamin B6 antagonism, we propose that 15% whole flaxseed overcomes S. enterica’s insult to estrogen synthesis by sustaining the activity of phosphatidylethanolamine methyltransferase (PEMT) in liver. We also propose that 10% defatted flaxseed (as a metformin homologue) strengthens chicken immunity by safeguarding gonadal physiology and by increasing plasma thymidine bioavailability. The concepts in this review can be used as a template for conducting advanced immunological studies in poultry science.

Rapid population response to a hunting ban in a previously overharvested, threatened landbird

AbstractEmpirical data are essential to assess the outcomes of management decisions in the context of adaptive management. We used flyway‐level population indices of a declining game bird to assess population changes after introducing hunting management measures as part of the European Union (EU)‐wide Adaptive Harvest Management mechanism (AHMM). In one flyway, a full hunting ban led to the start of population recovery; numbers increased by 25% in 2 years and the 10‐year population trend improved from “moderate decline” to “stable.” In the other flyway, harvest was only reduced (allegedly by 60% although statistics from key countries were incomplete), and numbers continued to fall (−15% decline). Our study shows positive results of the leading AHMM for a landbird in Europe and provides empirical evidence of the speed of population response and the timeframe needed for change to occur and to be detected. It showcases the successful application of policy mechanisms underpinned by science.

Northern bobwhite (Colinus virginianus) population response to anthelminthic treatment in the Rolling Plains ecoregion of Texas, 2014–2016

Northern bobwhite quail (Colinus virginianus) are an economically significant gamebird that has experienced continued general decline in the Rolling Plains ecoregion of Texas. Habitat loss and changing environmental conditions have been cited as major contributors to this decline, with factors such as parasites being considered inconsequential. To better assess the impacts of parasite infections on bobwhite populations in the Rolling Plains, bobwhite abundance was monitored in response to anthelminthic treatment. With the prevalence of Oxyspirura petrowi and Aulonocephalus pennula infections in quail from Mitchell County, Texas confirmed by previous studies, the anthelminthic agent Fenbendazole was introduced as a means of parasite control in 2014–2015. Bobwhite abundance was determined through a series of call counts which provided an index of bobwhite populations and were conducted throughout the course of the study. In 2016, call counts revealed a significant increase of bobwhite in the area subject to Fenbendazole treatment, while untreated areas showed no changes in abundance. Fall populations of bobwhite in the treated zone approached 300% of those in untreated areas, these findings suggest that parasites may have a more significant impact on quail populations in the Rolling Plains than previously suspected. With the importance of bobwhite as a game bird in the Rolling Plains, the potential impacts of parasites must be taken into consideration as a factor contributing to bobwhite declines. Further research into the long-term effects these parasites have on quail populations in the ecoregion may aid landowners in developing affordable and effective conservation strategies.

Regional demography of Icelandic rock ptarmigan and its implications for harvest management

Abstract The rock ptarmigan (Lagopus muta) is a popular game bird in Iceland, but management of hunting has tended to be controversial. We were interested in whether regional differences in ptarmigan demography exist, and if so, their implications for harvest management. We fit integrated population models (IPMs) to monitoring data from six hunting regions of Iceland during 2005–2023, and then examined equilibrium and non‐equilibrium harvest strategies based on an objective to maximize sustainable harvest. Survival and reproductive rates tended to be similar amongst regions, except in the demographically important Northeast, where survival was lower and productivity was higher. There was a negative relationship between post‐breeding age ratio (juveniles/adults) and spring abundance in all regions, although the strength of density dependence varied. Spring abundance was temporally stable in all regions, although harvest rates tended to decline, and adult survival rates tended to increase. Evidence for cyclical patterns in abundance was weak except in the Northeast, but this may be an artifact of the relatively short time series. Sustainable harvest potential varied amongst regions and was greatest in the East and Northeast. It appears that harvests during 2005–2022 were somewhat less than the sustainable maximum. Non‐equilibrium harvest strategies, in which the allowable harvests depend on spring population size and anticipated productivity, are so‐called ‘bang‐bang’ strategies, meaning that no or very little harvest is optimal until the population is at or above its maximum level of net production. Practical implications. Regional differences in ptarmigan demography warrant different harvest strategies. Yet, the hunting season in Iceland historically has been regulated on a country‐wide basis, with population abundance and dynamics in the Northeast playing a key role. To implement regional harvest management, decision makers must first agree on harvest management objectives that satisfy most stakeholders, who tend to hold very diverse values. Moreover, the historical relationship between season length and harvest rate is tenuous, yet season length is the primary mechanism traditionally used in Iceland to control harvest. The uncertainty in this relationship could be addressed in an adaptive‐management framework.

Re-emergence of Bagaza virus in wild birds from southern Spain

Bagaza virus (BAGV; Orthoflavivirus bagazaense) is an emerging vector-borne flavivirus affecting avian species with severe implications for animal health, and whose zoonotic potential has also been suggested. The aim of the present study was to monitor the epidemic outbreak of BAG in wild birds from Spain in 2021. BAGV cases were confirmed in game bird species, including red-legged partridges (Alectoris rufa) and common pheasants (Phasianus colchicus) from 24 hunting areas. Suspected cases (clinical signs and/or mortality compatible with BAGV infection but without molecular confirmation) were also detected in 11 additional hunting areas. The outbreaks showed a seasonality mainly restricted to July and August. Estimated morbidity [25.8% (95%CI: 11.3-40.3) in partridges and 8.7% (95%CI: 0.0-18.0) in pheasants] and mortality rates [27.3% (95%CI: 12.5-42.1) in partridges and 13.0% (95%CI: 1.9-24.1) in pheasants] were found in the affected hunting areas. In addition, 215 non-game birds belonging to 46 different species were sampled by passive surveillance upon admittance to rehabilitation centres during 2021. BAGV infection was detected for the first time in green woodpecker (Picus viridis), spoonbill (Platalea leucorodia), white stork (Ciconia ciconia) and cynereous vulture (Aegypius monachus), expanding the host range of this emerging pathogen. In contrast to other species, gamebirds showed distinct BAGV related lesions, primarily myocarditis and encephalitis in addition to inflammatory infiltrates and necrosis in the liver and kidney. Molecular analyses revealed a homology of 97.4-98.0% and 92.5-92.7% between the BAGV sequences obtained in the present study (492bp) and those isolated in 2010 and 2019 in southern Spain, respectively. These results allow to hypothesize about the likely silent and endemic circulation of BAGV since 2010 in this European region, although repeated virus reintroduction from neighbouring territories cannot be ruled out. Our findings evidence the sanitary, ecological and conservation implications of the re-emerged BAGV for wild birds, also emphasising the need to increase surveillance for monitoring and early detection of flavivirus dynamics in high-risk areas.

A Research on Gaziantep Chukar production station

Chukar (Alectoris chukar), is one of the most popular game birds in Turkey. The generation of this species has been greatly reduced in the last century. It is possible to reproduce this bird species, to bring it to nature, to develop hunting tourism in our country, to make special hunting areas and to earn income from hunting tourism. Chukar (Alectoris chukar) is found over a large areas in Turkey as well as over the world. Unfortunately, their population has been decreasing due to human pressure in the country. Breeding stations have been established for the production of this species in Turkey in order to increase their population and make them available for hunting. The breeding stations are the areas where the extinct species are artificially produced and the facilities required for production are established. Their main purpose is to produce extensively species in artificially established facilities, and to place these animals in suitable habitats or new production stations and to benefit from animals placed in production stations as new breeding stations. Chukar breeding, some people in Turkey just as a hobby, is made by some government agencies and research purposes Faculties of Agriculture and Veterinary some universities with the aim to ensure the continuation of his generation in recent years. In this study, located in Gaziantep province, studies were carried out on the production and release of wild animals to the nature at the production stations. General information about the establishment of production stations, production techniques, working order, encountered problems, applications to be made to solve problems and precautions to be taken are given. A detailed investigation and research has been carried out on Chukar Production Station established in Gaziantep province. In this context, Gaziantep Chukar Production Station is located at the provincial borders. After the production of hunting and wild animals produced in this station, they are placed in nature in the docking sites. In this study, deficiencies and problems of the production station mentioned above have been revealed.

Annual variation in attribute importance to upland game hunter satisfaction in Nebraska

AbstractTo sustain recreational hunting participation, we need to identify what makes a hunting experience satisfying. Merely identifying which factors are important to hunter satisfaction may be insufficient, however, as factor importance could vary across consecutive hunting seasons. Using online surveys, completed by individuals who hunted upland game in Nebraska, USA, from 2018 to 2022, we applied importance grid analysis (IGA) and penalty–reward contrast analysis (PRCA) to examine how activity‐specific factors influenced satisfaction across 5 consecutive hunting seasons. Results suggested consistent differences between the explicit (perceived importance) and implicit (performance) importance of factors for each hunting season. Factors related to seeing birds and harvest held greater implicit importance than expected based on explicit importance ratings (τ > 0.55, P < 0.05), whereas factors relating to access and other hunters held relatively lower implicit importance (τ < 0.31, P < 0.05). The PRCA method consistently identified seeing game birds as a minimum requirement to upland game hunting (penalty β < −0.26, P < 0.01). However, factors relating to harvest, access, and other hunters emerged as important only within certain seasons. Using IGA and PRCA provided valuable insights about the importance of hunters seeing game birds, and how aspects of different hunting seasons may improve satisfaction for hunters.

Anas platyrhynchos (Mallard) has been replacing Anas rubripes (American Black Duck) in human-altered landscapes in Ontario, 1996 to 2019

Abstract Anas rubripes (American Black Duck) has received much attention over the years as a popular game bird species that experienced historical declines on its wintering grounds. Declines may be due to changes in the quality and quantity of breeding habitat, competition with A. platyrhynchos (Mallard), or both. Although the A. rubripes population has stabilized, spatial variation in regional population trends of A. rubripes on their breeding grounds can provide insight into the relative importance of these alternative hypotheses at provincial and local scales. We analyzed indicated breeding pairs count data collected in Ontario between 1996 and 2019 through the Eastern Waterfowl Survey to evaluate the correlation in breeding densities and trends of the 5 most abundant waterfowl species. We also tested whether habitat and anthropogenic disturbance variables could explain the distribution of those species. Overall, A. platyrhynchos breeding pair densities increased across the survey area, whereas A. rubripes breeding pair densities decreased in the southern and northern part of the survey area but remained stable in the central part. Densities of breeding pairs of A. rubripes and A. platyrhynchos were negatively correlated across survey plots but the trends in breeding densities were not correlated. Densities of A. platyrhynchos breeding pairs increased in human altered landscapes, whereas the density of A. rubripes breeding pairs was negatively correlated with agriculture. Our results suggest that A. platyrhynchos did not competitively exclude A. rubripes on the breeding grounds, but instead, A. rubripes were replaced by A. platyrhynchos following encroachment of agriculture into A. rubripes breeding habitat. Habitat management plans focused on breeding A. rubripes should emphasize reduction in the expansion of anthropogenic perturbations and increases in habitat conservation efforts in the central area of the breeding range in Ontario.

Long-read de novo assembly of the red-legged partridge (Alectoris rufa) genome

The red-legged partridge (Alectoris rufa) is a popular game bird species that is in decline in several regions of southwestern Europe. The introduction of farm-reared individuals of a distinct genetic make-up in hunting reserves can result in genetic swamping of wild populations. Here we present a de novo genome assembly for the red-legged partridge based on long-read sequencing technology. The assembled genome size is 1.14 Gb, with scaffold N50 of 37.6 Mb and contig N50 of 29.5 Mb. Our genome is highly contiguous and contains 97.06% of complete avian core genes. Overall, the quality of this genome assembly is equivalent to those available for other close relatives such as the Japanese quail or the chicken. This genome assembly will contribute to the understanding of genetic dynamics of wild populations of red-legged partridges with releases of farm-reared reinforcements and to appropriate management decisions of such populations.

Exploration of gut microbial diversity of pheasants through pyrosequencing of 16S rRNA gene.

Despite the diversity of microbiota in birds is similar to that of other animals, there is a lack of research on the gut microbial diversity of nondomesticated bird species. This study aims to address this gap in knowledge by analyzing the bacterial communities present in the gut of two important game bird species, the Ring-necked pheasant (Phasianus colchicus) and the Green pheasant (Phasianus versicolor) to understand the gut microbial diversity of these species. The gut microbiome of 10 individual pheasants from two different species was studied using pooled fecal samples. We used 16S rRNA gene sequencing on the Ion S5 XL System next-generation sequencing with Mothur and SILVA Database for taxonomic division. An average of 141 different operational taxonomic unitswere detected in the gut microbiome. Analysis of microbial classification revealed the presence of 191 genera belonging to 12 different phyla in both pheasants. Alpha diversity indices revealed that P. colchicus exhibited most prevalence firmicutes with bacillus species microbial community than P. versicolor. Alpha diversity indices indicated that P. colchicus had a more diverse community and P. versicolor had a greater diversity of evolutionary lineages, while both species had similar levels of species richness and sample inclusiveness. These findings may have implications for the health and well-being of pheasants, serving as a reference for their bacterial diversity. Additionally, they provide a baseline for future research and conservation efforts aimed at improving the health and well-being of these and possibly other avian species.

New coccidian Eimeria iyoensis n. sp. (Apicomplexa: Eucoccidiorida: Eimeriidae) in farmed ring-necked pheasants (Phasianus colchicus L.) in Ehime, Japan.

Eight Eimeria spp. (Apicomplexa: Eimeriidae) have been isolated from the ring-necked pheasant (Phasianus colchicus Linnaeus), native to the temperate zone of Asia and eastern regions of Europe. Enteric coccidiosis has become a major issue associated with the breeding of farmed pheasants for game bird release or meat production. In this study, 35 fecal samples were collected from two-to-three-month-old ring-necked pheasants from four pheasant-rearing farms in Ehime Prefecture, Japan. Microscopic examination using a saturated sugar solution technique detected numerous subspherical oocysts from the samples of one farm and ellipsoidal Eimeria phasiani Tyzzer, 1929 oocysts from the three other farms. The subspherical oocysts were artificially sporulated and measured 18.6 µm by 15.7 µm with a 1.18 shape index (n = 150). Each oocyst contained four 10.7 µm × 5.8 µm sporocysts (n = 30) and one coarse refractile polar granule; no micropyle or residua were detected. Each sporocysts contained two sporozoites with one large and one small refractile body and sparsely distributed residua. The complete, 1,443-bp cytochrome c oxidase subunit I gene (cox1) of this isolate exhibited low sequence identity with published Eimeria spp. sequences including E. phasiani that was previously recorded in the same area. Meanwhile, the oocyst morphology most closely resembled that of Eimeria tetartooimia Wacha, 1973, but with distinct refractile polar granules and sporocyst residua. The available GenBank cox1 sequence of E. tetartooimia exhibited a sequence identity of < 94.5% with the study isolate. Here, the coccidian isolate identified in this study represents a new Eimeria iyoensis n. sp. capable of infecting ring-necked pheasant.

Chemerin abundance in egg white and its expression with receptors in extra-embryonic annexes of Pekin ducks: implications for embryo development

Embryonic mortality is a significant problem in the commercial duck industry worldwide. Therefore, identification of new biomarkers for duck embryo development is necessary. In the chicken (order Galliformes), we previously showed that chemerin is a hormone locally produced by the reproductive tract in hens, particularly in the magnum area, leading to its accumulation in the egg white and within the embryo annexes during embryonic development. We therefore hypothesized that the chemerin concentration in egg white could be a biomarker of egg performance and reproductive parameters in Pekin ducks (order Anseriformes). Thus, we collected eggs from Pekin ducks over a 5-day period at three stages of the laying period (before the laying peak, after the laying peak, and at the end of the laying period) to measure the chemerin concentrations in egg white by enzyme-linked immunosorbent assay. The chemerin concentration in egg white decreased during the laying period and was not associated with reproductive parameters. We found negative correlations between the chemerin level in egg white and the albumen weight. Reverse-transcriptase quantitative polymerase chain reaction showed that chemerin and its three receptors CMKLR1, GPR1, and CCRL2 were expressed in the reproductive tract and within allantoic and amniotic annexes during embryo development. Chemerin concentrations strongly increased in amniotic fluid on embryonic day 16 (ED16) when the egg white was transferred into the amniotic sac. Finally, chemerin inhibition in egg white by in ovo injections of anti-chemerin antibodies (0.01, 0.1, and 1 µg) increased the embryo mortality rate. These data demonstrate the important role of the chemerin system during egg formation and embryo development in Pekin ducks, suggesting their potential use as biomarkers for determining the quality of poultry eggs and embryo development.

Land cover and space use influence coyote carnivory: evidence from stable-isotope analysis

For many species, the relationship between space use and diet composition is complex, with individuals adopting varying space use strategies such as territoriality to facilitate resource acquisition. Coyotes (Canis latrans) exhibit two disparate types of space use; defending mutually exclusive territories (residents) or moving nomadically across landscapes (transients). Resident coyotes have increased access to familiar food resources, thus improved foraging opportunities to compensate for the energetic costs of defending territories. Conversely, transients do not defend territories and are able to redirect energetic costs of territorial defense towards extensive movements in search of mates and breeding opportunities. These differences in space use attributed to different behavioral strategies likely influence foraging and ultimately diet composition, but these relationships have not been well studied. We investigated diet composition of resident and transient coyotes in the southeastern United States by pairing individual space use patterns with analysis of stable carbon (δ13C) and nitrogen (δ15N) isotope values to assess diet. During 2016–2017, we monitored 41 coyotes (26 residents, 15 transients) with GPS radio-collars along the Savannah River area in the southeastern United States. We observed a canopy effect on δ13C values and little anthropogenic food in coyote diets, suggesting 13C enrichment is likely more influenced by reduced canopy cover than consumption of human foods. We also observed other land cover effects, such as agricultural cover and road density, on δ15N values as well as reduced space used by coyotes, suggesting that cover types and localized, resident-like space use can influence the degree of carnivory in coyotes. Finally, diets and niche space did not differ between resident and transient coyotes despite differences observed in the proportional contribution of potential food sources to their diets. Although our stable isotope mixing models detected differences between the diets of resident and transient coyotes, both relied mostly on mammalian prey (52.8%, SD = 15.9 for residents, 42.0%, SD = 15.6 for transients). Resident coyotes consumed more game birds (21.3%, SD = 11.6 vs 13.7%, SD = 8.8) and less fruit (10.5%, SD = 6.9 vs 21.3%, SD = 10.7) and insects (7.2%, SD = 4.7 vs 14.3%, SD = 8.5) than did transients. Our findings indicate that coyote populations fall on a feeding continuum of omnivory to carnivory in which variability in feeding strategies is influenced by land cover characteristics and space use behaviors.

FOUR-WEEK ORAL ADMINISTRATION OF BALOXAVIR MARBOXIL AS AN ANTI-INFLUENZA VIRUS DRUG SHOWS NO TOXICITY IN CHICKENS.

High pathogenicity avian influenza is an acute zoonotic disease with high mortality in birds caused by a high pathogenicity avian influenza virus (HPAIV). Recently, HPAIV has rapidly spread worldwide and has killed many wild birds, including endangered species. Baloxavir marboxil (BXM), an anti-influenza agent used for humans, was reported to reduce mortality and virus secretion from HPAIV-infected chickens (Gallus domesticus, order Galliformes) at a dosage of ≥2.5 mg/kg when administered simultaneously with viral challenge. Application of this treatment to endangered birds requires further information on potential avian-specific toxicity caused by repeated exposure to BXM over the long term. To obtain information of potential avian-specific toxicity, a 4-wk oral repeated-dose study of BXM was conducted in chickens (n = 6 or 7 per group), which are commonly used as laboratory avian species. The study was conducted in reference to the human pharmaceutical guidelines for nonclinical repeated-dose drug toxicity studies to evaluate systemic toxicity and exposure. No adverse changes were observed in any organs examined, and dose proportional increases in systemic exposure to active pharmaceutical ingredients were noted from 12.5 to 62.5 mg/kg per day. BXM showed no toxicity to chickens at doses of up to 62.5 mg/kg per day, at which systemic exposure was approximately 71 times higher than systemic exposure at 2.5 mg/kg, the reported efficacious dosage amount, in HPAIV-infected chickens. These results also suggest that BXM could be considered safe for treating HPAIV-infected endangered birds due to its high safety margin compared with the efficacy dose. The data in this study could contribute to the preservation of endangered birds by using BXM as a means of protecting biodiversity.

Viral pathogen detection in U.S. game-farm mallard (Anas platyrhynchos) flags spillover risk to wild birds.

The threat posed by emerging infectious diseases is a major concern for global public health, animal health and food security, and the role of birds in transmission is increasingly under scrutiny. Each year, millions of mass-reared game-farm birds are released into the wild, presenting a unique and a poorly understood risk to wild and susceptible bird populations, and to human health. In particular, the shedding of enteric pathogens through excrement into bodies of water at shared migratory stop-over sites, and breeding and wintering grounds, could facilitate multi-species long-distance pathogen dispersal and infection of high numbers of naive endemic birds annually. The Mallard (Anas platyrhynchos) is the most abundant of all duck species, migratory across much of its range, and an important game species for pen-rearing and release. Major recent population declines along the US Atlantic coast has been attributed to game-farm and wild mallard interbreeding and the introduction maladaptive traits into wild populations. However, pathogen transmission and zoonosis among game-farms Mallard may also impact these populations, as well as wildlife and human health. Here, we screened 16 game-farm Mallard from Wisconsin, United States, for enteric viral pathogens using metatranscriptomic data. Four families of viral pathogens were identified - Picobirnaviridae (Genogroup I), Caliciviridae (Duck Nacovirus), Picornaviridae (Duck Aalivirus) and Sedoreoviridae (Duck Rotavirus G). To our knowledge, this is the first report of Aalivirus in the Americas, and the first report of Calicivirus outside domestic chicken and turkey flocks in the United States. Our findings highlight the risk of viral pathogen spillover from peri-domestically reared game birds to naive wild bird populations.

Different Evolutionary Trends of Galloanseres: Mitogenomics Analysis.

The two existing clades of Galloanseres, orders Galliformes (landfowl) and Anseriformes (waterfowl), exhibit dramatically different evolutionary trends. Mitochondria serve as primary sites for energy production in organisms, and numerous studies have revealed their role in biological evolution and ecological adaptation. We assembled the complete mitogenome sequences of two species of the genus Aythya within Anseriformes: Aythya baeri and Aythya marila. A phylogenetic tree was constructed for 142 species within Galloanseres, and their divergence times were inferred. The divergence between Galliformes and Anseriformes occurred ~79.62 million years ago (Mya), followed by rapid evolution and diversification after the Middle Miocene (~13.82 Mya). The analysis of selective pressure indicated that the mitochondrial protein-coding genes (PCGs) of Galloanseres species have predominantly undergone purifying selection. The free-ratio model revealed that the evolutionary rates of COX1 and COX3 were lower than those of the other PCGs, whereas ND2 and ND6 had faster evolutionary rates. The CmC model also indicated that most PCGs in Anseriformes exhibited stronger selective constraints. Our study suggests that the distinct evolutionary trends and energy requirements of Galliformes and Anseriformes drive different evolutionary patterns in the mitogenome.

Selection of suitable reference genes for normalization of RT-qPCR in three tissues of Northern bobwhite (Colinus virginianus) infected with eyeworm (Oxyspirura petrowi).

The Northern bobwhite (Colinus virginianus) is an economically important, and popular game bird in North America. Northern bobwhites have experiencing declines of > 3.5% annually in recent decades due to several factors. The eyeworm Oxyspirura petrowi is a nematode parasite frequently found in the eyes of bobwhites. Although reported frequently in wild bobwhites, there is no research to understand the host-parasite mechanism. Hence, it is important to investigate mechanisms of eyeworm invasion and immune modulation in bobwhite. Cytokine gene expression using RT-PCR is widely used to identify the innate immune response of a host to an infection. In this study, we evaluated ten reference genes (HMBS, RPL19, RPL32, RPS7, RPS8, TATA, SDHA, YWHAZ, GAPDH, and ACTB) for their stability across three tissues (liver, spleen, and caecal tonsils) of control and O. petrowi infected Northern bobwhites. Primer efficiency and reference genes stability were assessed using GeNorm, NormFinder, and BestKeeper. Expression of these reference genes with respect to O. petrowi infection in bobwhites showed RPL32 and HMBS were the most stable genes in the liver, HMBS and SDHA were the most stable genes in the spleen, and HMBS and YWHAZ were equally stable reference genes in the caecal tonsils. Based on the geometric mean of all three analyses, our results indicate that the combination of RPL32 and HMBS for the liver, HMBS and SDHA for the spleen, and YWHAZ and HMBS for caecal tonsils might be used as reference genes for normalization in gene expression investigations on Northern bobwhites.

Investigation of Enteric Parasites with a Focus on Zoonotic Parasites in the Feces of Galliformes.

Galliformes have a global distribution and are bred by humans as domestic animals or game birds. The world's poultry population is increasing due to high consumer demand for poultry products. Due to the increasing growth of Galliformes breeding, this study aimed to investigate gastrointestinal parasites in the feces of some species of Galliformes. In the present study, 100 distinct fecal samples were collected from seven different Galliformes species, including rural chickens, peacocks, partridges, pheasants, turkeys, quails, and guinea fowls. Sampling of each bird was performed separately, and these birds were kept in cages. In order to identify gastrointestinal parasites, the samples were evaluated using the Clayton-Lane method, the Modified Ziehl-Neelsen, and the Trichrome staining methods. Among 100 birds sampled, 53% were positive for gastrointestinal parasites. Moreover, 30%, 18%, and 5% of birds were infected with Eimeria spp., nematodes, and Giardia spp., respectively. The highest rate of parasitic infestation in Galliformes was related to protozoan infections, and the highest rate of protozoan infection was related to Eimeria (30%). In addition, complex infestation was not detected. Considering that most parasitic infections have been detected in apparently healthy birds, it is recommended to observe hygiene to regularly disinfect cages and reduce the density of birds in the nests. Due to the zoonotic potential of Giardia and the contamination of some birds with this parasite, this issue should be considered by public health officials, bird sellers' markets, owners, and breeders of these birds.