Light and Electron Microscopic Examination of the Cervical Portions of the Esophagus in the Muscovy Duck (Cairina moschata)
Abstract
Objective: The esophagus in poultry serves as a primary conduit for food transport and, in many species, a specialized organ for temporary storage and conditioning. This study aimed to elucidate the anatomical, histological, and surface ultrastructural features of the esophagus and crop in the Muscovy duck, focusing on regional specializations related to its feeding ecology. Materials and Methods: Tissue samples were collected from ten healthy adult Muscovy ducks across three distinct regions: the cervical esophagus (Region 1), the crop (Region 2), and the post-crop esophagus (Region 3). The samples were processed for light microscopy (H&E and PAS staining) and scanning electron microscopy (SEM) to evaluate the mucosal architecture and glandular distribution. Results: Histological examination revealed that the entire esophageal tract is lined with a protective stratified squamous epithelium. A significant regional variation was observed in the density of esophageal glands, which were markedly more abundant in Region 1, suggesting an intensive lubrication requirement during the initial stages of deglutition. In the crop (Region 2), the tunica muscularis was notably thinner, facilitating the organ's expansion for food storage. A unique finding was the close anatomical association between the mucosal glands and lymphoid follicles, indicating a specialized local immune barrier. SEM analysis demonstrated intricate microridge patterns on the epithelial surface of transport zones, whereas the crop exhibited prominent glandular openings and a dense mucociliary network designed for food softening. Conclusions: The findings indicate that the Muscovy duck esophagus is a morphologically dynamic organ with distinct regional adaptations. The high glandular density and robust lymphoid presence highlight a dual specialization for both efficient food processing and mucosal defense, reflecting the evolutionary requirements of a surface-feeding waterfowl.
Keywords
Ethical Statement
This study was approved by the Sivas Cumhuriyet University Local Ethics Committee for Animal Experiments with decision number 65202830-050.04.04-125 dated 26.12.2025.
References
- Ali HM, Ali KA, Taha AM. Comparative anatomical, histological, and electron microscopical studies on the cervical region of the esophagus in some birds with different diet habits. J Adv Vet Res. 2023; 13(2):181-187.
- Alsanosy AA, Noreldin AE, Elewa YH, Mahmoud SF, Elnasharty MA, Aboelnour A. Comparative features of the upper alimentary tract in the domestic fowl (Gallus gallus domesticus) and kestrel (Falco tinnunculus): A morphological, histochemical, and scanning electron microscopic study. Microsc Microanal. 2021; 27(1):201-214.
- Denbow DM. Gastrointestinal anatomy and physiology. In: Scanes CG, Dridi S, eds. Sturkie's Avian Physiology. 7st ed. New York: Academic Press; 2015. pp.337-366.
- El‐naseery NI, Mohammed AA, Abuel‐Atta AA, Ghonimi WA. Species‐specific differences of the avian oesophagus: Histological and ultrastructural study. Anat Histol Embryol. 2021; 50(5):788-800.
- Gussekloo S. Feeding structures in birds. Feeding in domestic vertebrates: from structure to behaviour. USA: CABI Publishing; 2006.
- Hanafy BG. A focus on the gross morphological and ultrastructural characteristics of the oesophagus and stomach of Eurasian common moorhen (Gallinula chloropus chloropus, Linnaeus 1758). Microsc Res Tech. 2021; 84(10):2244-2253.
- Hanafy BG, Abumandour MM, Bassuoni NF. Morphological features of the gastrointestinal tract of Garganey (Anas querquedula, Linnaeus 1758)-Oesophagus to coprodeum. Anat Histol Embryol. 2020; 49(2):233-250.
- Kierończyk B, Rawski M, Długosz J, Świątkiewicz S, Józefiak D. Avian crop function-A review. Ann Anim Sci. 2016; 16(3):653-678.
- King AS, McLelland J. Birds: Their Structure and Function. 2nd ed. Liverpool: Bailliere Tindall; 1984. pp.93-110.
- Konig HE. Digestive system (Systema digestorium). In: Konig HE, Korbel R, Liebich HG, eds. Avian Anatomy: Textbook and Colour Atlas. 2nd ed. Essex: 5m Books Ltd; 2016. pp.125-155.
- Madkour F, Mohamed SA, Abdalla KE, Ahmed YA. Developmental studies of the gastric junctions of the post-hatching Muscovy duck (Cairina moschata). SVU- Int J Vet Sci. 2018; 1(2):69-84.
- Madkour FA, Mohamed SA, Abdalla KE, Ahmed YA. Developmental stages and growth of the proventriculus of post‐hatching Muscovy duck: Light and electron microscopic study. Microsc Res Tech. 2022; 85(1):56-70.
- Mahdy MA, Mohammed ES. Anatomical, histological, and scanning electron microscopic features of the esophagus and crop in young and adult domestic pigeons (Columba livia Domestica). BMC Vet Res. 2024; 20(1):428.
- Shawki N, Mahmoud F, Mohamed M. Seasonal variations of the digestive tract of Egyptian rock dove, columba livia: anatomical, histological and scanning electron microscopical studies. Assiut Univ J Zool. 2021; 50:60-97.
- Singh B. Birds. In: Singh B, ed. Dyce, Sack, and Wensing’s Textbook of Veterinary Anatomy. 5th ed. St. Louis: Saunders; 2018. pp.794-831.
- Zhu L. Histological study of the oesophagus and stomach in Grey-Backed Shrike (Lanius tephronotus). Int J Morphol. 2015; 33(2): 655-660
Details
| Primary Language | English |
|---|---|
| Subjects | Veterinary Anatomy and Physiology, Veterinary Histology and Embryology |
| Journal Section | Research Article |
| Authors | |
| Submission Date | February 9, 2026 |
| Acceptance Date | March 9, 2026 |
| Publication Date | March 30, 2026 |
| DOI | https://doi.org/10.47748/tjvr.1885197 |
| IZ | https://izlik.org/JA58SD76MT |
| Published in Issue | Year 2026 Volume: 10 Issue: 1 |
Cite
Aim & Scope
The aim of the Turkish Journal of Veterinary Research (TJVR) is to publish, in a timely manner, peer-reviewed reports of the highest quality research that has the clear potential to enhance the health, welfare, and performance of animals and humans. The journal will maintain the highest ethical standards of scientific journalism and promote such standards among its contributors. In addition, the journal will foster global interdisciplinary cooperation in veterinary medical research.
The Turkish Journal of Veterinary Research supports the collaborative exchange of information between researchers and clinicians by publishing novel research findings that bridge the gulf between basic research and clinical practice or that help to translate laboratory research and preclinical studies to the development of clinical trials and clinical practice. The journal welcomes submission of high-quality original studies, review articles and other academic papers in a wide range of scientific fields, including anatomy, anesthesiology, animal welfare, behavior, epidemiology, genetics, heredity, infectious disease, molecular biology, oncology, pharmacology, pathogenic mechanisms, physiology, surgery, theriogenology, toxicology, and vaccinology. Species of interest include production animals, companion animals, equids, exotic animals, birds, reptiles, and wild and marine animals. Reports of laboratory animal studies and studies involving the use of animals as experimental models of human diseases are considered only when the study results are of demonstrable benefit to the species used in the research or to another species of veterinary interest. Other fields of interest or animal species are not necessarily excluded from consideration, but such reports must focus on novel research findings. Submitted papers must make an original and substantial contribution to the veterinary medicine knowledge base.
Author Guidelines
Download the Instructions for Authors.
Download the Title Page Sample.
Ethical Principles and Publication Policy
PUBLICATION POLICY
MISSION and SCOPEThe Turkish Journal of Veterinary Research (TJVR) is a biannual (March-April and November-December), open access, peer-reviewed veterinary medical journal that publishes manuscripts online in the general area of veterinary medical research.
The mission of the Turkish Journal of Veterinary Research (TJVR) is to publish, in a timely manner, peer-reviewed reports of the highest quality research that has the clear potential to enhance the health, welfare, and performance of animals and humans. The journal will maintain the highest ethical standards of scientific journalism and promote such standards among its contributors. In addition, the journal will foster global interdisciplinary cooperation in veterinary medical research.
The TJVR academic journal is available online for free at https://dergipark.org.tr/. All manuscripts published in our journals are licensed under CC BY NC 4.0 (Creative Commons license).
The TJVR supports the collaborative exchange of information between researchers and readers by publishing novel research findings in veterinary interest. The journal welcomes submission of high-quality original research, review articles, technical innovation, case series case reports and other academic papers.
Prior Publication
Authorship: Individuals should be listed as authors only if they
(1) made a substantial contribution to the conception and design of the study, the acquisition of the data used in the study, or the analysis and interpretation of that data;
(2) were involved in drafting or revising the manuscript critically for important intellectual content; and
(3) approved the submitted version of the manuscript and will have an opportunity to approve subsequent revisions of the manuscript, including the version to be published.
Each individual listed as an author must have participated sufficiently to take public responsibility for the work. Acquisition of funding, collection of data, or general supervision of the research team does not, alone, justify authorship.
All responsibility for the scientific content and statements in an article published in the TJVR belongs to the authors.
A manuscript containing previously published information may be rejected on the grounds of prior publication. Publication of abstracts containing less than 250 words will not be considered to constitute prior publication, but publication of longer abstracts may be. Authors are encouraged to consult the guidelines for preparation of scientific abstracts when preparing scientific abstracts for publication. In general, figures, tables, footnotes, and references should not be included in abstracts.
At the time of manuscript submission, the corresponding author must include copies of any abstracts of the manuscript that have been published or submitted for publication or that are expected to be submitted for publication, along with copies of any closely related manuscripts or manuscripts with substantially similar content.
The Editor-in-Chief has the discretion to reject the manuscript straight off before or after sending it to the reviewers for reviewing.
Review Process
1. The works sent to the journal are primarily subject to editorial evaluation in terms of the suitability of the journal's purpose and scope, compliance with the spelling rules and instructions for authors.
At this stage, works that are not suitable for the purpose and scope of the journal are returned to the authors.
Works that do not comply with the spelling rules and instruction for authors format are returned to the authors for correction and re-upload.
A manuscript is received with the understanding that the information has not been published or submitted for publication in any compiled printed (eg, journals, symposia, proceedings, newsletters, or books) or electronic (eg, websites, CD-ROMs, DVDs, or blogs) format in English or any other language and will not be published or submitted for publication elsewhere while the manuscript is under consideration by TJVR.
2. For evaluated works, the editor determines two reviewers suitable for the subject and nature of the work and starts the reviewer process.
3. Reviewers are given a 15 days evaluation period. At the end of this period, the reviewers who do not complete the evaluation or upload the evaluation report are terminated and new reviewers are determined.
4. According to the results of the reviewer evaluation, the works that are not found appropriate to be published are returned to the authors. The authors are informed whose works accepted for publication and the study is published in the next issue.
5. The authors are given 30 days for the works that the reviewers want to be corrected. During this period, the needed corrections should be made and uploaded to the journal system. If this period, which is given to the authors, is exceeded, the process of the study is terminated and it should be uploaded as a new article from the beginning.
6. if it is needed the uploaded revised version in the given time is redirected to the reviewer and the second step reviewer process is started; if the reviewer did not want to see the corrected version of the work, the editor makes the decision on the publication.
7. During the second step evaluation process, the corrections made by the authors are evaluated by the reviewers and the reviewers inform the editor about their final decisions about the study.
8. The editor informs the authors regarding the publishing process according to this decision.
Copyright
TJVR is covered by copyright. All authors will be required to transfer copyright to the editorial board prior to publication of any manuscript or letter.
Authors must obtain and submit a statement of permission from the copyright holder (most often, the author or publisher) if they wish to include items such as figures, tables, or appendices that appeared or will have appeared in other published reports prior to publication of the manuscript, regardless of the originating source.
Original artwork (eg, drawings or photographs) that was created specifically for use in the manuscript must be accompanied by a letter explaining the conditions under which the work was created. The letter must be signed by the artist and specify the rights given to the authors for use of the artwork and the rights retained by the artist (if any). If rights are retained by the artist, the letter must include a statement that allows the journal to use the material for publication in print and online.
Authors should certify that neither the manuscript nor its main contents have already been published or submitted for publication in another journal with the Copyright Transfer Form.
Ethical Policy
Publication Ethics
Conflicts of Interest and Financial Disclosures
A conflict of interest exists whenever an individual has financial interests or personal relationships that might consciously or unconsciously influence his or her decisions. Conflicts of interest are ubiquitous and cannot be completely eliminated; they do not, by themselves, indicate improper behavior, wrongdoing, or scientific misconduct.
Financial relationships are the most easily identifiable conflicts of interest and include, among other things, ownership, employment, consultancies, honoraria, paid expert testimony, grants, patents, stock ownership or options, and service as an officer or board member. Other types of conflicts of interest include personal relationships, academic competition, and intellectual beliefs.
All authors must disclose in the Acknowledgments section of the manuscript any financial or personal relationships that could be perceived to influence or could give the appearance of influencing information in the submitted manuscript. This includes detailed information about all relevant financial interests, activities, relationships, and affiliations (other than affiliations listed on the title page of the manuscript) occurring at the present time or within the 3 years prior to manuscript submission. In this context, relevant financial interests, activities, relationships, and affiliations should be interpreted broadly. For example, authors should disclose relationships they have not only with companies that manufacture products that are the subject of research described in the manuscript but also with companies that manufacture competing products. If no such conflicts of interest existed, the following statement or an equivalent may be included:
The authors declare that there were no conflicts of interest.
The editors reserve the right to reject any manuscript because of conflicts of interest. Failure to fully disclose conflicts of interest may be grounds for rejection or retraction of the manuscript.
Conflicts of interest of authors, reviewers, editors and the journal will handling with principles of the COPE.
Ethical Rules for Parties
Editor's Responsibilities:
We mainly follow the Committee on Publication Ethics (COPE)'s Code of Conduct and Best Practice Guidelines for Journal Editors.
Editor guarantees that the content of submitted articles will be kept confidential to anyone other than the corresponding author, reviewers, and the publisher.
The editor should not disclose any information of the reviewers to a third party without the permission of the reviewers.
The editor has the right to make the final decision on whether to accept or reject a manuscript regarding the significance, originality, and clarity of the manuscript and its relevance to the journal.
The editor should not use for his or her research any part of any data or work reported in submitted and as yet unpublished articles.
Reviewer's Responsibilities:
We mainly follow the Committee on Publication Ethics (COPE)'s COPE Ethical Guidelines for Peer Reviewers.
The reviewer who thinks he or she is not qualified to assess the related manuscript or who thinks he or she couldn't evaluate the manuscript until the deadline needs to report as early as possible to editor these situations.
If the conflict of interest is in question the reviewer should inform the editor to recuse himself or herself from reviewing from the manuscript.
The reviewer should not disclose the manuscript with others, except authorization by the editor.
The reviewer should be in a professional manner to evaluate the manuscript, personal criticism is not welcomed.
Author's Responsibilities:
The author should not submit the manuscript to multiple journals.
The author should highlight the importance and of the manuscript in the submission process by presenting a brief report.
Publishers, editors, reviewers, and readers are entitled to request the author to provide the raw data for his or her research for the convenience of editorial review and public access.
The author should guarantee the originality of the manuscript.
The author should indicate explicitly all sources that have supported the research and also declare any conflict(s) of interest.
The author should give proper acknowledgment to contributors of the research.
Research Ethics
Researchers are expected to be wise on research ethics and follow the research ethics on their works.
For this purpose you can examine related sources (NIH).
Humane Animal Care and Use
It is obligatory to submit the ethical committee documents in the studies that require an ethical committee evaluation.
To be considered for publication in TJVR, all research studies involving animals must have been performed in compliance with guidelines outlined in the Animal Welfare Act (http://awic.nal.usda.gov/government-and-professional-resources/federal-laws/animal- welfare-act), US Public Health Service Policy on the Humane Care and Use of Laboratory Animals (http://grants.nih.gov/grants/olaw/references/phspol.htm), National Research Council’s Guide for the Care and Use of Laboratory Animals (http://www.nap.edu/read/5140/chapter/1), or Guide for the Care and Use of Agricultural Animals in Research and Teaching (http://adsa.org/Publications/FASS2010AgGuide.aspx) or in compliance with equivalent guidelines. If animals were euthanized, the method of euthanasia must be indicated in the manuscript. If a method not recommended, a justification for use of this method must be provided.
A manuscript containing information that suggests animals were subjected to adverse, stressful, or harsh conditions or treatments will not be considered for publication unless the authors demonstrate convincingly that the knowledge gained was of sufficient value to justify these conditions or treatments.
Publication Fees
Publication of the accepted manuscripts is free of charge.
TJVR does not accept advertising cooperations.
Complaint Policy
The journal will make every effort to resolve complaints without any doubt. For this purpose, the journal will follow the COPE's related flowcharts. Complaints can be made by sending email to infotjvr@gmail.com.
Price Policy
Publication of the accepted manuscripts is free of charge.
Indexes
Citation Indexes
Other Indexes
Journal Boards
Editor in Chief
Technical Editors
Prof. Dr. İsmail Hakkı Ekin, 1971 Yılında Siirt'te doğdu. İlk ve ortaöğrenimini Van'da tamamladı. 1989 yılında Van Teknik Lisesi Motor Bölümünü birincilikle bitirdi. 1990 yılında girdiği Van Yüzüncü Yıl Üniversitesi Veteriner Fakültesinden 1995 yılında mezun oldu. Aynı yıl kısa dönem askerlik görevini yerine getirerek, Temmuz 1996’da terhis oldu. 1997’de Van Yüzüncü Yıl Üniversitesi Veteriner Fakültesi’nde Araştırma Görevliliğine atandı. Van Yüzüncü Yıl Üniversitesi Sağlık Bilimleri Enstitüsü Veteriner Mikrobiyoloji Anabilim Dalında başladığı Yüksek Lisans öğrenimini 1998 yılında, Doktora öğrenimini ise 2004 yılında bitirerek Bilim Doktoru (PhD) unvanını aldı. Dr. Araştırma görevlisi olarak 2 yıl süreyle görev yaptıktan sonra Şubat 2006’da Dr. Öğretim Üyesi (Yrd. Doç. Dr.) kadrosuna atandı. Van Yüzüncü Yıl Üniversitesi Sağlık Bilimleri Enstitüsü Besin Hijyeni ve Teknolojisi Anabilim Dalındaki ikinci Doktora eğitimini de 2022 yılında bitirerek ikinci Bilim Doktoru (PhD) unvanını aldı. 2013 yılında Doçentlik unvanını alan Ekin, 2018 yılında Van Yüzüncü Yıl Üniversitesi Veteriner Fakültesi Mikrobiyoloji Anabilim Dalında Profesörlük kadrosuna atandı. Halen bu birimde Anabilim Dalı Başkanı olarak görevini sürdürmekte olup evli ve üç çocuk babasıdır.
Advisory Board
Bu eser Creative Commons Atıf-GayriTicari 4.0 Uluslararası Lisansı ile lisanslanmıştır.