Occurrence of astrovirus in young racing pigeons and genome characterization of 2 new astrovirus genomes representing 2 new species.

Enteropathies are a serious concern in racing pigeons as they significantly impair performance in races and their training, and viruses are suspected to be one of the main factors. Astroviruses are well-known to be responsible for causing enteric disease in humans and various other animals including birds, although their prevalence and pathogenicity in pigeons is poorly understood. In this study, we investigated 2 groups of young racing pigeons (sick-study group and healthy-control group) to assess the correlation between the number of astrovirus genome copies in cloacal swabs and the occurrence of enteropathy. To determine this, we developed a novel TaqMan quantitative PCR (qPCR) and digital droplet PCR (ddPCR) methods for astrovirus detection and absolute quantitative analysis. We also performed high-throughput sequencing to obtain the complete genome sequences and establish the genetic similarity of the obtained strains to known astroviruses of poultry and other avian species. Two new complete genome sequences of pigeon astroviruses in the Avastrovirus genus were identified, representing 2 new species. These were found most closely related to astroviruses identified in Columbidae species and chickens. They share an average of 75.8% genome-wide pairwise identity and 57.6% and 64.6% capsid protein sequence identity with other unclassified columbid avastrovirus sequences in GenBank. Although the difference in prevalence of astrovirus in the study and control group was found statistically insignificant, there was a significant difference between the number of genome copies in positive samples from both groups. These unambiguous results leave the role of astroviruses as enteropathogenic factors in pigeons still undetermined.

Research Note: Effects of different light-emitting diode lights during egg incubation on hatching performance and embryo development in White King pigeons.

The light provide during incubation can influence hatching characteristics (hatching time, hatchability, etc.) and embryo development in chickens, geese, and turkeys. However, relevant studies on this factor in pigeons are lacking. This study investigated the effects of in ovo photostimulation during embryogenesis on hatching performance, squab quality, and embryo development in pigeons. 400 eggs from paired- bred pigeons were randomly distributed into 4 incubation lighting treatments, with 2 replicates per treatment. The treatments included dark as a control (NL), 12-h light, and 12-h dark photoperiods of white light (WL), red light (RL), and green light (GL) (100 lx at egg level) during the first 15 d of incubation. A total of 1,600 eggs in 4 batches from White King pigeons were used. The results showed that hatching time of the WL group was significantly shorter than that of the dark light group (P < 0.05). The hatchability of fertile eggs in the WL group was significantly higher (P < 0.05), whereas the hatchability of fertile eggs in the RL group was significantly lower (P < 0.05) than that of in the control group. Light stimulation had no effect on time to 90% hatching or average hatching time (P > 0.05). In addition, the hatch window was not extended by light stimulation (P > 0.05). The group incubated under GL showed an increase in embryo weight and relative leg muscle on embryonic d 14 and the hatching day compared to the dark incubation (P < 0.05). Green light stimulated the heart and liver development during the early and middle stages of embryogenesis. It was concluded that white light stimulation during embryogenesis accelerated the hatching process, whereas monochromatic green light had a positive effect on embryo development. Our findings provide important guidance for developing light protocols for pigeon egg incubation.

Hungry pigeons prefer sooner rare food over later likely food or faster information.

Introduction: Making decisions and investing effort to obtain rewards may depend on various factors, such as the delay to reward, the probability of its occurrence, and the information that can be collected about it. As predicted by various theories, pigeons and other animals indeed mind these factors when deciding. Methods: We now implemented a task in which pigeons were allowed to choose among three options and to peck at the chosen key to improve the conditions of reward delivery. Pecking more at a first color reduced the 12-s delay before food was delivered with a 33.3% chance, pecking more at a second color increased the initial 33.3% chance of food delivery but did not reduce the 12-s delay, and pecking more at a third color reduced the delay before information was provided whether the trial will be rewarded with a 33.3% chance after 12 s. Results: Pigeons' preference (delay vs. probability, delay vs. information, and probability vs. information), as well as their pecking effort for the chosen option, were analyzed. Our results indicate that hungry pigeons preferred to peck for delay reduction but did not work more for that option than for probability increase, which was the most profitable alternative and did not induce more pecking effort. In this task, information was the least preferred and induced the lowest level of effort. Refed pigeons showed no preference for any option but did not drastically reduce the average amounts of effort invested. Discussion: These results are discussed in the context of species-specific ecological conditions that could constrain current foraging theories.

Prevalence Study of Trichomonas gallinae in Domestic Pigeons in Northeastern Beijing and Experimental Model of Trichomoniasis in White King Squabs Measuring In Situ Apoptosis and Immune Factors in Crop and Esophagus.

Trichomonas gallinae (T. gallinae) is a flagellated protozoan and the causative agent of trichomoniasis, or canker, in birds. In the current study, the prevalence of T. gallinae was firstly investigated in five breeds. According to the results of the prevalence study, White King pigeons were selected as the experimental animals. A total of 135 White King squabs at one day of age were randomly divided into two groups and raised in separate isolators. The challenged group (N = 100) was challenged intranasally with 5 × 106 parasites/mL of the T. gallinae strain, and the control group (N = 35) was intranasally administered medium of equivalent volume. At 1, 2, 3 and 5 days post infection (DPIs), the crops and esophagi were collected for RNA extraction and formaldehyde fixation. The results showed that prevalence of T. gallinae in the five breeds ranged from 27.13% (White Carneau) to 43.14% (White King). After the challenge, mild microscopic lesions were observed in both tissues. Apoptosis rates were higher in the challenged group than in the control group at 2 and 5 DPIs in the crop and at 1, 2 and 7 DPIs in the esophagus. For both tissues, relative expression of IL-1ß increased dramatically at the beginning and decreased at 5 DPIs, and TGF-ß increased stably in the challenged group.

Geometric morphometric analysis of beak shape of Columbimorphae (Columbas, Van, Mardin and Dönek).

Selective breeding over centuries has led to the emergence of numerous pigeon breeds from the single species Columba livia, showcasing unparalleled phenotypic diversity. In Eastern Turkey, Van pigeons originate, while Tumbler pigeon varieties thrive countrywide, reflecting local traditions. The avian beak, vital for survival, offers insights into domestication and traits influenced by natural selection. Geometric morphometrics, a shape analysis method, allows for a comprehensive examination of beak shapes among domestic pigeons, providing a nuanced understanding of their complexity. Understanding beak diversity in pigeons, especially those found in Turkey, enhances our knowledge of avian evolution and adaptation processes. The study utilized 48 skulls from 4 pigeon breeds, including wild rock pigeons and domestic pigeons of Tumbler, Mardin and Van breeds, all free from pathological lesions and adults. Geometric morphometric analyses of beak shape were conducted using dorsal and lateral photographs, with landmarks placed using tpsDig software. MorphoJ software facilitated procrustes analysis and principal component analysis (PCA) to assess morphological variability and differentiate pigeon breeds based on shape patterns, with significance set at p < 0.05. PCA revealed significant shape variations among pigeon breeds, with 47 principal components identified for lateral beak views and 36 principal components for dorsal views. Canonical variates analysis further distinguished morphological patterns among breeds, indicating distinct shape variations in both dorsal and lateral views, elucidating the unique characteristics of each breed's beak morphology. Our results demonstrate statistically significant differences in pigeon beak shape, particularly in the lateral view, confirming the importance of these variations (p < 0.05) and suggesting that such differences occur less than 5% of the time under the null hypothesis.

The course of Rotavirus A (RVA) infection in young racing pigeons during the racing season.

BACKGROUND: Pigeon Rotavirus A (RVA) infection has been confirmed in pigeons in the last decade as a cause of Young Pigeon Disease (YPD). Although YPD has been known for many years to date, no studies have been conducted to track the spread of RVA infection in pigeons during the racing season. The presented research aims to determine the course of RVA infection during the flights of young racing pigeons in the summer season, in one of the districts in the Mazovian Voivodeship in Poland. RESULTS: Faecal samples of pigeons collected from transport baskets in vehicles transporting pigeons to the starting point were tested. The quantitative RT-PCR (qRT-PCR) was used to detect the genetic material of RVA. Samples taken during 6 flights were analysed. The study showed a percentage increase in infections up to the fourth flight of pigeons, and then their decrease. With Cq values below 20, breeders did not participate in the next flight and/or reported disease in the flock. With positive Cq values of 20 to 30, clinical signs of disease were not reported. Of the 76 breeders participating in the races, at least one positive result was found in 46 (60.5%). Including the occurrence of the disease during the racing season was reported by 11 breeders (14.4%). The main clinical signs in sick pigeons were vomiting, diarrhea and stowed crop. The tested pigeons were not vaccinated against RVA. CONCLUSIONS: During training and racing of pigeons, it is not possible to avoid exposing them to pathogens, including RVA, regardless of whether pigeons from different breeders are placed in the same baskets or are in separate baskets. However, after four flights the number of new cases of the disease decreases which indicates the development of immunity. The qRT-PCR test is useful in the diagnosis and differentiation of clinical (Cq below 20) and subclinical RVA infections in racing pigeons.

Manure enriched with nitrogen derived from high-protein food waste in a large dining facility.

Food waste (FW) from large dining facility has been a pressing environmental challenge in China recently. This study developed an innovative species-specific feeding strategy for producing pigeon meat and excellent manure from FW. Adding FW to the feed of pigeons significantly increased their feed intake and promoted their growth although the pigeons showed a strong aversion to the FW. We produced a "super manure" with exceptionally high nitrogen (N) content (mean = 10.77 % on a dry basis, 8.04-12.57 %, n = 264) by feeding slowly-growing pigeon species (Columba livia vs. and Caoge Huzhou 11) with protein-high commercial feed and FW. A significant negative relationship between the N and carbon (C) contents in the pigeon manure was found, with C depletion higher than N depletion. Furthermore, the N content in the anaerobic composting (AnC) manure was 29.16 % higher than that in the FW. Fourier transform infrared (FT-IR) analysis and stable isotopes δ13C and δ15N in the manure clearly identified the transformations of nutrients during pigeon feeding and the AnC process. This study opens a path for producing N-high manure using protein-high food waste.

Characteristics of changes in volatile organic compounds and bacterial communities in physically preserved pigeon breast meat.

To understand the relationship between changes in aroma and bacteria in pigeon breast meat (PBM) during preservation, bacterial communities and volatile compounds in PBM were analyzed using high-throughput sequencing and gas chromatography-ion mobility spectrometry. Analyses of total viable bacteria counts revealed that modified atmospheric packaging (MAP) and electron beam irradiation (EBI) could be used to extend the shelf-life of PBM to 10 d and 15 d, respectively. Furthermore, Lactococcus spp. and Psychrobacter spp. were the dominant bacterial genera of the MAP and EBI groups, respectively. The results of the study revealed 91 volatile organic compounds, one of which, butanal, was the most intense volatile organic compound while being an important source of aroma differences between the physical preservation techniques. Alpha-terpinolene, acetoin-M, gamma-butyrolactone, 1-hexanol-M, and 2,6-dimethyl-4-heptanone may be markers of PBM spoilage. During preservation, the MA group (treatment with 50 % CO2 + 50 % N2) demonstrated greater stabilization of PBM aroma. A Spearman correlation analysis showed that Lactococcus spp., Psychrobacter spp., and Pseudomonas spp. were the dominant bacterial genera of PBM during preservation and were closely related to an increase in the intensity of anisole, 2-methyl-3-furanthiol, and 5-methyl-2-furanmethanol, respectively. Lactococcus spp. and Psychrobacter spp. play crucial roles in the sensory degradation of PBM. In this study, we analyzed the changes in bacterial genera and volatile organic compounds of PBM under different physical preservation techniques to identify a suitable method for preserving PBM and evaluating its freshness.

Two Doses of Zn Induced Different Microbiota Profiles and Dietary Zinc Supplementation Affects the Intestinal Microbial Profile, Intestinal Microarchitecture and Immune Response in Pigeons.

We aimed to explore the effects of two different doses of Zn on the fecal microbiota in pigeons and the correlation between these effects and intestinal immune status. Zn doses affected pigeon growth performance, and pigeons in the T60 (60 mg/kg Zn) and T90 (90 mg/kg Zn) groups exhibited higher villus height and crypt depth in duodenum and ileum compared to the control group, respectively. Supplementation with Zn increased the expression of the IL8, CD798, TJP and NKTR genes (p < 0.05), while enhancing serum immunoglobulin (Ig) G, IgM, and IgA concentrations compared to the control pigeons (p < 0.05). T60 treatment reduced relative Actinobacteriota abundance, while Lactobacillus spp. abundance was highest in the T90 group compared to the two other groups. The core functional genera significantly associated with immune indices in these pigeons were Rhodococcus erythropolis and Lactobacillus ponti. Our findings will help facilitate the application of dietary Zn intake in pig production.

Exploring protein structural adaptations and polyphenol interactions: Influences on digestibility in pigeon pea dal and whole grains under heat and germination conditions.

Pigeon pea, a protein-rich legume with low protein digestibility (PD) due to its high polyphenol content and other antinutritional factors (ANFs). Consequently, processing methods are crucial to improve PD. We investigated the effects of thermal treatments (cooking, hydrothermal, autoclaving, infrared rays) treatments and germination on modulation of PD, its properties and association with ANFs in two distinct genotypes based on polyphenol content: high (Pusa Arhar 2018-4) and low (ICP-1452). Treatments improved in vitro PD and essential amino acid content, with autoclaving showing significantly higher PD (ICP-1452: 90.4%, Pusa-Arhar 2018-4: 84.32%) ascribed to disruption of tight protein matrices. Significant increase in ß-turn, reduction in protein: starch, protein: polyphenol interactions as well as breakdown of storage proteins revealed by the analysis of protein structural properties. This study suggests thermal treatments, particularly autoclaving, can enhance pigeon pea protein's nutritional quality for its utilization as a new ingredient in development of healthy foods.

CircRNAs involved in the red light of effect on follicle selection in pigeons.

Red light (RL) can enhance egg production in poultry. CircRNAs play a crucial role by serving as transcriptional regulators. However, their role in influencing follicle development in White King pigeons remains unexplored. In this study, 54 paired White King pigeons were chosen and divided into RL and white light (WL) groups, each with 3 subgroups. The egg production of paired pigeons in each replicate was recorded for 45 d, and the characteristics of follicle development were monitored during the laying interval (LI). The granulosa cell layer from follicles of the second-largest follicle (F2) was collected, and high-throughput sequencing was performed to elucidate the molecular mechanism of follicle development in pigeons. The study confirmed that RL enhances egg production in pigeons. Additionally, under RL, the F2 follicle was selected, while under WL, small follicles were kept on the third day (LI3). A total of 5,510 circRNAs were identified across all samples, revealing differentially expressed circRNAs (DECs) in various comparisons: 627 in RF1 vs. WF1, 900 in RF2 vs. WF2, 606 in RF1 vs. RF2, and 937 in WF1 vs. WF2. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that host genes of DECs were enriched in pathways like steroid hormone biosynthesis, oocyte meiosis, GnRH signaling pathway, and apoptosis pathway. Moreover, circRNA_5497, circRNA_2016, and circRNA_3328 were common DECs across 4 groups, sharing miRNA binding sites with follicle selection-associated genes. In conclusion, our findings suggest that RL promotes egg production by stimulating follicle selection during LI, offering insights into the regulatory mechanisms of circRNAs in follicle selection under RL. This knowledge can help enhance the reproductive performance of pigeons.

Effects of dietary Chitosan oligosaccharides supplementation on Th17/Treg balance and gut microbiota of early weaned pigeon squabs.

Our previous study found that early weaning is associated with decreased growth performance, intestinal barrier impairment, and an imbalance in Th17/Treg in pigeon squabs. Chitosan oligosaccharides (COS) has been substantiated to regulate gut microbiota and restore Th17/Treg equilibrium in mammals, thereby ameliorating growth performance. However, the potential effects of COS in altricial birds remain unclear. Three hundred healthy 7-day-old American king pigeon squabs were selected with similar body weights and randomly divided into 5 groups. The 5 treatment groups were as follows: the control group (CON), fed with artificial pigeon milk; 4 supplementation groups, fed with artificial pigeon milk +100 (COS1), 150 (COS2), 200 (COS3), and 250 (COS4) mg/kg COS, respectively. Results showed that dietary supplementation of COS significantly enhanced the growth performance of weaned squabs. Compared to the CON group, the COS groups exhibited increased villus length and villus area in the jejunum and ileum, accompanied by improvements in morphological structure and mucosal permeability. COS was found to reduce the levels of Th17-associated cytokines and increase the levels of Treg-associated cytokines. COS downregulated the expression of retinoic acid receptor-related orphan receptor C (RORC), a key transcription factor of Th17 cells, while upregulated the expression of Forkhead box protein P3 (FOXP3), a key transcription factor of Treg cells. Dietary COS supplementation increased gut bacterial diversity, altered the relative abundance of several bacteria taxa and enhanced the concentration of short-chain fatty acids (SCFA). Correlation analysis demonstrated a close association between gut microbiota, SCFAs, and indicators related to the Th17/Treg balance. Moreover, we found that SCFAs correlated more strongly with Th17/Treg-related indexes than gut microbiota. These results demonstrated that COS could relieve early weaning stress in pigeon squabs and the optimal dosage of dietary COS supplementation was suggested to be 200 mg/kg. In addition, COS had a protective effect on maintaining intestinal immune balance by modulating microbiota and Th17/Treg related signaling pathways, in which SCFAs might play a crucial role as messengers.

The pigeon circovirus evolution, epidemiology and interaction with the host immune system under One Loft Race rearing conditions.

This study was aimed to investigate the frequency of PiCV recombination, the kinetics of PiCV viremia and shedding and the correlation between viral replication and host immune response in young pigeons subclinically infected with various PiCV variants and kept under conditions mimicking the OLR system. Fifteen racing pigeons originating from five breeding facilities were housed together for six weeks. Blood and cloacal swab samples were collected from birds every seven days to recover complete PiCV genomes and determine PiCV genetic diversity and recombination dynamics, as well as to assess virus shedding rate, level of viremia, expression of selected genes and level of anti-PiCV antibodies. Three hundred and eighty-eight complete PiCV genomes were obtained and thirteen genotypes were distinguished. Twenty-five recombination events were detected. Recombinants emerged during the first three weeks of the experiment which was consistent with the peak level of viremia and viral shedding. A further decrease in viremia and shedding partially corresponded with IFN-γ and MX1 gene expression and antibody dynamics. Considering the role of OLR pigeon rearing system in spreading infectious agents and allowing their recombination, it would be reasonable to reflect on the relevance of pigeon racing from both an animal welfare and epidemiological perspective.

The amino acid sensor MetRS is required for methionine-induced milk protein synthesis in a domestic pigeon model.

This study was conducted to investigate whether methionyl-tRNA synthetase (MetRS) is a mediator of Met-induced crop milk protein synthesis via the janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5) signalling pathway in breeding pigeons. In Experiment 1, a total of 216 pairs of breeding pigeons were divided into 3 groups (control, Met-deficient, and Met-rescue groups). In Experiments 2 and 3, forty pairs of breeding pigeons from each experiment were allocated into 4 groups. The 2nd experiment included a control group and 3 MetRS inhibitor (REP8839) groups. The 3rd experiment included a Met-deficient group, Met-sufficient group, REP8839 + Met-deficient group, and REP8839 + Met-sufficient group. Experiment 1 showed that Met supplementation increased crop development, crop milk protein synthesis, the protein expression of MetRS and JAK2/STAT5 signalling pathway, and improved squab growth. Experiment 2 showed that crop development, crop milk protein synthesis, and the protein expression of MetRS and the JAK2/STAT5 signalling pathway were decreased, and squab growth was inhibited by the injection of 1.0 mg/kg BW REP8839, which was the selected dose for the 3rd experiment. These results showed that Met supplementation increased crop development, crop milk protein synthesis, and the expression of MetRS and JAK2/STAT5 signalling pathway and rescued squab growth after the injection of REP8839. Moreover, the Co-IP results showed that there was an interaction between MetRS and JAK2. Taken together, these findings indicate that MetRS mediates Met-induced crop milk protein synthesis via the JAK2/STAT5 signalling pathway, resulting in improved squab growth in breeding pigeons.

Formation and retention of aroma compounds in pigeons roasted by circulating non-fried roast technique by means of UHPLC-HRMS and GC-O-MS.

Lipids are key aroma contributors in meat products. However, the role of different lipids in the presence of aroma compounds in roasted pigeons has not been studied. The formation of aroma compounds and lipids during the circulating non-fried roasting of pigeons was investigated. The results presented that 18 aroma compounds, including 5-methy-2,3-diethylpyrazine, were identified as key aroma compounds. A total of 6324 lipids were classed into 47 categories, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triglyceride (TG). Nine lipids, containing PA(P-20:0/22:4(7Z,10Z,13Z,16Z)) and LPC 16:0-SN1, showed promise as potential biomarkers for discriminating differential pigeons using OPLS-DA. PC (13.76%), TG (13.58%), and their products were major lipids, among which TG 16:0 16:0 18:2, LPC 18:2-SN1, and PC 18:1_18:1 played a crucial role in the presence of aroma compounds. Interestingly, the linoleic acid, an important aroma contributor, was predominantly bonded to the sn-2 position of phospholipid and sn-3 position of neutral lipids.

Rapid detection of pigeon adenovirus 2 using a TaqMan real-time PCR assay.

Pigeons infected with aviadenoviruses have been found worldwide. Recently, pigeon adenovirus 2 (PiAdV-2) has been widely distributed in racing pigeons in Germany. However, the epidemiology of this virus remains unclear due to the lack of a specific detection platform for PiAdV-2. In this study, we first detected PiAdV-2 positivity in racing pigeons (designated FJ21125 and FJ21128, which share 100% nucleotide identity with each other based on the fiber 2 gene) in Fujian, Southeast China. These genes shared 99.8% nucleotide identity with PiAdV-2 (GenBank No. NC_031501) but only 54.1% nucleotide identity with PiAdV-1 (GenBank No. NC024474). Then, the TaqMan-qPCR assay for the detection of PiAdV-2 was established based on fiber 2 gene characterization. The established assay had a correlation coefficient of 1.00, with an amplification efficiency of 99.0%. The minimum detection limit was 34.6 copies/µL. Only PiAdV-2 exhibited a positive fluorescent signal, and no signal was detected for other pathogens (including PiCV, FAdV-4, FAdV-8a, EDSV, PPMV-1, RVA and PiHV). The assay has good reproducibility, with a coefficient of variation less than 2.42% both intragroup and intergroup. The distributions of PiAdV-2 in fecal samples from YPDS (35 samples) and healthy (43 samples) racing pigeons from different geographical areas were investigated and were 37.14% (YPDS) and 20.93% (healthy), respectively. In summary, we developed a TaqMan-qPCR platform for the detection of PiAdV-2 infection with high sensitivity, specificity, and reproducibility. We confirmed the presence of PiAdV-2 in China, and our data suggested that there is no indication of a correlation between YPDS and PiAdV-2. This study provides more information on the pathogenesis mechanism and epidemiological surveillance of PiAdV-2.

Intestinal health of squab pigeons responded to parental dietary protein levels during breeding period.

The objective of this study was to determine the effects of dietary crude protein (CP) levels on intestinal antioxidant status, tight junction proteins expression, and amino acids transporters levels in squabs. A total of 180 pairs of White King parent pigeons approximately 10 mo old were randomly assigned to 5 groups with 6 replications of 6 pairs of parental pigeons each, and were fed with 14, 15, 16, 17, and 18% CP diets for 46 d, respectively. Dietary increasing CP levels increased final body weight (linear and quadratic, P < 0.05), serum urea nitrogen (linear, P<0.05) and triglyceride levels (quadratic, P < 0.05), and reduced kidney relative weight (quadratic, P < 0.05) in squabs. Final body weight of squabs in the 18% CP diet group was higher than that of the 14, 15, and 16% CP diet groups (P < 0.05) but was similar to that of the 17% CP diet group (P > 0.05). Increasing dietary CP levels reduced intestinal malondialdehyde contents (linear and quadratic, P < 0.05) and jejunal total superoxide dismutase (T-SOD) activity (linear, P < 0.05), and enhanced (linear and quadratic, P<0.05) ileal catalase and T-SOD activities in squabs, and these effects were more prominent in the 17% CP diet group. Graded CP levels up-regulated the mRNA expression of intestinal zonula occludens 1 (linear, P < 0.05), solute carrier family 7 members 9 (linear, P < 0.05) and claudin 1 (CLDN1, linear and quadratic, P < 0.05), ileal CLDN3 and solute carrier family 6 members 14 (linear, P < 0.05) but lowered jejunal solute carrier family 6 member 14 (quadratic, P<0.05) mRNA expression in squabs. The effects of dietary CP levels on intestinal tight junction proteins expression were more apparent when its supplemental levels were 18%. These results suggested that increasing parental dietary CP levels ranged from 14 to 18% during breeding period improved growth and intestinal function of squabs, with its recommended level being 17%.

Meningoencephalitis with malacia caused by Sarcocystis calchasi in a rock pigeon in Japan.

Sarcocystis spp. cause pigeon protozoan encephalitis, a neuronal disease. A female pigeon exhibiting torticollis had a necrotic area in the cerebral hemisphere surrounded by lesions with perivascular cuffing, gliosis, granulomatous foci, and meningitis. Non-necrotic lesions were also observed in the brainstem. Intact and degenerative schizonts were observed within the neuropils and neurons in the lesions. Deoxyribonucleic acid (DNA) was extracted from paraffin-embedded brain tissues and genetically analyzed after gel electrophoresis to determine Sarcocystis spp. using specific primer sets for 28S ribosomal ribonucleic acid and internal transcribed spacer region-1. DNA sequencing confirmed a significant homology with S. calchasi. This is the first report of meningoencephalitis with malacia caused by S. calchasi in a rock pigeon in Japan.

Recombinant Viruses from the Picornaviridae Family Occurring in Racing Pigeons.

Viruses from Picornaviridae family are known pathogens of poultry, although the information on their occurrence and pathogenicity in pigeons is scarce. In this research, efforts are made to broaden the knowledge on Megrivirus B and Pigeon picornavirus B prevalence, phylogenetic relationship with other avian picornaviruses and their possible connection with enteric disease in racing pigeons. As a result of Oxford Nanopore Sequencing, five Megrivirus and two pigeon picornavirus B-like genome sequences were recovered, among which three recombinant strains were detected. The recombinant fragments represented an average of 10.9% and 25.5% of the genome length of the Pigeon picornavirus B and Megrivirus B reference strains, respectively. The phylogenetic analysis revealed that pigeons are carriers of species-specific picornaviruses. TaqMan qPCR assays revealed 7.8% and 19.0% prevalence of Megrivirus B and 32.2% and 39.7% prevalence of Pigeon picornavirus B in the group of pigeons exhibiting signs of enteropathy and in the group of asymptomatic pigeons, respectively. In turn, digital droplet PCR showed a considerably higher number of genome copies of both viruses in sick than in asymptomatic pigeons. The results of quantitative analysis leave the role of picornaviruses in enteropathies of pigeons unclear.

Putative Probiotic Ligilactobacillus salivarius Strains Isolated from the Intestines of Meat-Type Pigeon Squabs.

This study aims to screen for potential probiotic lactic acid bacteria from the intestines of meat-type pigeon squabs. Ligilactobacillus salivarius YZU37 was identified as the best comprehensive performed strain. Being acid- and bile salt-tolerant, it displayed growth-inhibition activities against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium SL1344, exhibited sensitivity to 6 commonly used antibiotics, and endowed with good cell surface hydrophobicity, auto-aggregation property, and anti-oxidant activities. Results of in vitro experiments indicated that the bacteriostatic effects of this strain were related to the production of proteinaceous substances that depend on acidic conditions. Whole-genome sequencing of L. salivarius YZU37 was performed to elucidate the genetic basis underlying its probiotic potential. Pangenome analysis of L. salivarius YZU37 and other 212 L. salivarius strains available on NCBI database revealed a pigeon-unique gene coding choloylglycine hydrolase (CGH), which had higher enzyme-substrate binding affinity than that of the common CGH shared by L. salivarius strains of other sources. Annotation of the functional genes in the genome of L. salivarius YZU37 revealed genes involved in responses to acid, bile salt, heat, cold, heavy metal, and oxidative stresses. The whole genome analysis also revealed the absence of virulence and toxin genes and the presence of 65 genes distributed under 4 CAZymes classes, 2 CRISPR-cas regions, and 3 enterolysin A clusters which may confer the acid-dependent antimicrobial potential of L. salivarius YZU37. Altogether, our results highlighted the probiotic potential of L. salivarius YZU37. Further in vivo investigations are required to elucidate its beneficial effects on pigeons.