Japanese Quail Sex Ratios: What Eight Generations Showed
Quick Look
Researchers examined 4,282 Japanese quail offspring records from 968 dams across eight generations.
The tested factors showed no statistically significant associations with offspring sex ratio.
The results do not prove exact equality or provide a reliable way to produce more females.
Study at a Glance
Species: Japanese quail (Coturnix japonica)
Breed/Line: A line selected for early growth and an unselected control
Number of Birds: 4,282 offspring records from 968 dams
Study Duration: Eight generations; sex confirmed at 35 days
Country: Egypt
Journal: Tropical Animal Health and Production
Year: 2024
Research Focus: Offspring sex ratio, selection generation, breeding line, age at first egg and body weight at first egg
Study Overview
Do selection generation, breeding line, age at first egg, or body weight at first egg affect offspring sex ratio in Japanese quail? The researchers examined these factors to better understand sex-ratio variation. For keepers, the question is whether those hen characteristics offer a useful basis for predicting more female offspring.
How Was the Study Conducted?
The researchers analyzed 4,282 offspring records from 968 dams across eight generations, comparing a line selected for early growth with an unselected control. Chi-square tests and logistic regression examined the recorded sex ratios. Sex was assessed by plumage from 21 days and confirmed at 35 days. Only dam records without offspring mortality were included.
Key Findings
The analyses found no statistically significant associations between the tested factors and offspring sex ratio. Small patterns in particular generations and a weight group were exploratory, not demonstrated sex biases.
Strengths of the Study
The study followed two breeding lines across eight generations and used pedigree and hatching records. It examined several dam characteristics together rather than relying on the outcome of a single hatch.
Limitations of the Study
These results do not prove exact equality or predict every hatch. This was one research population; only dam records without offspring mortality were included. The study did not directly sex embryos at fertilization. Published subgroup counts differ between tables, so this review does not reproduce those subgroup figures. Its findings should not be transferred automatically to chickens or other species.
Poultry Nerds Takeaway
The review offers no reliable method for producing more females by choosing hens according to their age or weight at first egg. Keep the authors’ statistical findings separate from practical predictions for an individual flock.
Original Research
Emam, A. M., Semida, D. A., El-Full, E. A., Mahmoud, B. Y., Abdel-Azim, A. M., and Elnesr, S. S. (2024). Is the sex ratio of Japanese quail offspring equal? Tropical Animal Health and Production, 56, 384.
DOI: 10.1007/s11250-024-04224-3
Original publication / open-access full text: Springer Nature
Evidence basis: Full text examined.
How to Cite This Review
Poultry Nerds. (2026). Japanese Quail Sex Ratios: What Eight Generations Showed (Research Review). Poultry Nerds Research Library. Retrieved October 21, 2026, from https://www.poultrynerdspodcast.com/research-library/japanese-quail-offspring-sex-ratio
Research Review
This article summarizes a peer-reviewed scientific publication and explains its practical application for poultry keepers, breeders, and educators. It is an original review written by Poultry Nerds and is not a reproduction of the original manuscript. Readers are encouraged to review the complete publication using the original publisher and open-access links provided above.
Unless otherwise noted, the findings discussed apply only to the species, breed, age, and production system evaluated by the researchers. Results from a single study should not automatically be generalized to all poultry species, breeds, or management systems. Additional research may support, refine, or contradict these findings as scientific knowledge evolves.