2025.11.10
RESEARCH NEWS STORY
Food for Thought: How Amino Acids Affect Appetite in Newborn Chicks
Review article summarizes recent research in the biomolecular mechanisms that drive feeding behavior in poultry
Ensuring that chicks receive optimal nutrition is vital for their early growth and long-term productivity. In a review article published in The Journal of Poultry Science, Dr. Phuong V. Tran summarizes current understanding of how amino acids, and their metabolites regulate appetite in neonatal chicks. The article highlights that compounds such as L-ornithine act as rapid satiety signals that interact strongly with the appetite-stimulating neuropeptide Y, offering insights to improve feeding strategies in poultry production.
Image title: Overview of the study
Image caption: This infographic summarizes key aspects of the review article, highlighting the most relevant findings and takeaways.
Image credit: Dr. Phuong V. Tran from Kyushu University, Japan
License type: Original content
Usage restrictions: Cannot be reused without permission
In the poultry industry, ensuring chicks receive optimal nutrition is paramount, as it influences their early development, health, and long-term productivity. For decades, scientists have tried to unravel the biological mechanisms that control appetite and satiety during the early developmental phases of chicks—a key step toward designing effective feeding strategies. Interestingly, neonatal chicks are an excellent animal model for studying such biomolecular processes in detail. They are a precocial species that begins searching for food immediately after hatching, and their relatively large brains make it easier to administer substances directly into their central nervous system during experiments.
However, despite decades of research, many aspects of appetite regulation in chicks remain poorly understood. Chicks exhibit very short and frequent eating bouts separated by brief resting periods. While appetite is known to be regulated by neuropeptides, these signaling molecules take time to synthesize and act, implying that some other fast-acting signal must be controlling satiety. Could free amino acids, which are rapidly influenced by nutrient uptake, be involved in this process?
In a review article published in Volume 62 of The Journal of Poultry Science on March 15, 2025, Dr. Phuong V. Tran from the Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Japan, analyzes current knowledge on the regulation of food intake in neonatal chicks. The review focuses specifically on the role of amino acids and their metabolites and how they interact with the appetite-stimulating neuropeptide Y (NPY).
The analysis highlights that short-term refeeding leads to a rapid increase in the concentration of several free amino acids in the chick brain, supporting their role as acute satiety signals. In particular, L-ornithine, which is a metabolite of the amino acid L-arginine, had a potent effect on appetite, inhibiting food intake in a dose-dependent manner. Unlike other appetite-regulating mechanisms, L-ornithine appears to act independently of stress-related pathways.
One of the most critical findings detailed in the review was that, when co-injected with L-ornithine, the strong appetite-stimulating effect of NPY was significantly attenuated. “This implies a potent interaction in the brain between the regulation of food intake by NPY and acute satiety signals by L-ornithine,” remarks Dr. Tran. This interaction suggests that L-ornithine acts as a brake on the NPY-driven urge to eat, providing a fast-acting regulatory loop necessary for the chick’s frequent feeding behavior. The review also examined the roles of other amino acids, such as L-tryptophan and L-proline, noting that their effects on feeding are often tied to their influence on sedation and sleep, which frequently follows a feeding bout in neonates.
The various studies and key findings outlined in this review have implications that bridge basic biology with practical applications. “Knowledge of the key role played by amino acids in the overall network of the central nervous system in neonatal chicks can be used to adjust dietary amino acids for optimal performance in poultry production,” explains Dr. Tran. Simply put, this information can guide the formulation of chick feed to optimize the balance of amino acids, ensuring that chicks receive the best possible nutritional start, thus leading to healthier flocks. Moreover, insights into appetite biology gained using neonatal chicks as an animal model could have parallels in mammals, which are harder to study.
The continued exploration of these mechanisms could not only improve poultry nutrition and productivity but also deepen our understanding of how the brain regulates feeding across species.
Reference
| Title of original paper: | Function of Amino Acids and Neuropeptides in Feeding Behavior in Chicks |
|---|---|
| Authors | Phuong V. Tran1 |
| Affiliations | 1 Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan |
| Journal: | The Journal of Poultry Science |
| DOI | https://doi.org/10.2141/jpsa.2025013 |
Additional information for EurekAlert
| Latest Article Publication Date: | 15 March 2025 |
|---|---|
| Subject of Research: | Literature review |
| Subject of Research: | Animals |
| Conflicts of Interest Statement: | The authors declare no conflicts of interest. |
About Kyushu University, Japan
Founded in 1911, Kyushu University is one of Japan’s leading national research universities, located in Fukuoka on the island of Kyushu. The university is renowned for its strong emphasis on interdisciplinary research and innovation in science, engineering, agriculture, and life sciences. Its Graduate School of Bioresource and Bioenvironmental Sciences fosters cutting-edge studies in animal science, environmental sustainability, and food production systems. Through global collaborations and advanced research infrastructure, Kyushu University continues to contribute to solving critical challenges in food security, sustainable agriculture, and human and animal health.
About Japan Poultry Science Association
Founded in 1966, the Japan Poultry Science Association (JPSA) promotes the advancement of poultry science and industry in Japan and worldwide through both fundamental and applied research. The association organizes biannual scientific and general meetings, publishes two official journals—The Journal of Poultry Science (in English) and Japanese Journal of Poultry Science (in Japanese)—and recognizes outstanding contributions in research and technology.
Website: https://jpn-psa.jp/en/home-en/
About Phuong V. Tran from Kyushu University
Dr. Phuong V. Tran is a researcher specializing in animal nutrition and neurobiology. She completed her doctoral studies at Kyushu University, Japan, where her work focused on the neurochemical regulation of feeding behavior in neonatal chicks. Currently, she is affiliated with the Department of Animal Nutrition and Feed, National Institute of Animal Science, Hanoi, Vietnam. Her research explores how amino acids and neuropeptides interact to control appetite and stress responses in animals. Dr. Tran received the 2023 Encouragement Award from the Japan Poultry Science Association for her contributions to poultry physiology and nutrition research.
Funding information
Not available
Media Contact
Kazuhisa Honda
E-mail: honda@tiger.kobe-u.ac.jp
Web: https://jpn-psa.jp/en/home-en/
Expert contact
Phuong V. Tran
E-mail: vietphuongtran.vn@gmail.com