How Wider Egg Turning Improves Yolk Use and Goose Embryo Development

Incubation & Embryology
Written By Jennifer Bryant

Research Review

Goose eggs are larger than chicken eggs and often hatch less consistently in equipment built around chicken standards. This study compared 50° and 70° turning in Yangzhou goose eggs and examined not only hatch results, but also how the embryo used nutrients stored in the yolk.

Source Paper

Guo, B., Yan, L., Lei, M., Dai, Z., & Shi, Z. (2021). “Wider Angle Egg Turning during Incubation Enhances Yolk Utilization and Promotes Goose Embryo Development.” Animals, 11(9), 2485. Read the original research: https://doi.org/10.3390/ani11092485

Why This Paper Matters

Turning is often described simply as a way to prevent the embryo from sticking. This paper shows that its effects can reach further. Turning angle influenced late survival, embryo growth, hatch weight, and the way yolk lipids were mobilized during development.

Study at a Glance

  • Species: Domestic goose

  • Breed or line: Yangzhou goose

  • Eggs: 1,152

  • Treatments: 50° and 70° turning

  • Location: China

  • Journal and year: Animals, 2021

  • Outcomes: Fertilization, embryo mortality, day-22 embryo and yolk mass, hatchability, hatch weight, yolk lipidomics, and yolk-sac gene expression

How the Study Was Conducted

The 1,152 eggs were divided between 50° and 70° turning treatments, each with three replicates. Eggs were stored for three days at 20°C and 50% relative humidity, small-end down, then incubated at 37–38°C and 60–70% relative humidity. They were candled on days 7 and 18, transferred to the hatcher on day 28, and evaluated through hatch. A subset was sampled on day 22 for embryo, yolk, lipid, and gene-expression measurements.

Key Findings

  • Fertilization rate did not differ between turning groups.

  • Hatchability of fertile eggs was significantly higher with 70° turning.

  • Early and middle mortality did not differ, but late embryo mortality was lower at 70°.

  • Day-22 embryo mass and gosling hatch weight were higher with 70° turning.

  • The wider angle changed yolk lipid use and related gene expression, supporting a biological mechanism rather than a hatch-rate difference alone.

Practical Application

For goose eggs, turning angle can influence nutrient use, late survival, and gosling quality. A 70° program is evidence-based for the tested Yangzhou eggs and commercial equipment, but breeders should validate it against their own breed, tray geometry, fertility-adjusted hatch rate, and breakout records. Wider is only useful when eggs can move safely and consistently.

Strengths of the Study

  • The experiment included 1,152 eggs.

  • Two clearly defined turning angles were tested under otherwise standardized conditions.

  • Hatch results were supported by embryo growth, yolk lipidomics, and gene-expression measurements.

  • The study investigated a practical hatchery setting and a plausible biological mechanism.

Limitations of the Study

The study used one goose breed and commercial-style equipment. Other goose breeds, ducks, Muscovies, Call ducks, swans, chickens, turkeys, and quail were not tested. Molecular sampling was smaller than the full hatch cohort, and the work ended at hatch rather than measuring lifetime growth, health, or reproduction. A 70° angle should not be treated as a universal poultry standard.

Poultry Nerds Takeaway

In the tested goose eggs, 70° turning improved fertile-egg hatchability and embryo development while reducing late mortality and changing yolk utilization. Turning is not merely anti-sticking maintenance; it can shape the embryo’s access to membranes, nutrients, and space. Apply the finding by species and equipment, then verify it with your own records.

Continue the Incubation Research Cluster

Research Review Notice

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, not a reproduction of the manuscript. Findings apply to the species, breed, equipment, conditions, and outcomes evaluated by the researchers; additional research may support, refine, or contradict these findings.

Jennifer Bryant
Previous

Egg Storage Duration, Egg Quality, and Chicken Embryonic Development
Next

Optimizing Egg Turning Angle to Improve Pekin Duck Hatchability