The quality of animal products has never been more important. Research focused on improving food safety and reducing environmental impact, along with the obvious economic value of eggs, has been highlighted in Alex Rainey’s BSc Sustainable Agriculture thesis, “The Effect of Oviposition Time and Age on the Physical Parameters of Egg Quality.” Below is a quick summary of this project, which earned second place in the BSAS Undergraduate Thesis of the Year competition.

With global population projected to rise significantly over the next several decades, food demand and production have been identified as major areas for scientific focus. In developing regions, where eggs are a leading source of protein, the benefits of research like this are amplified. Populations that rely heavily on eggs stand to gain the most from improved production practices. These same regions often face limited healthcare access and reduced social support, meaning that food safety has a direct effect on public health and people’s ability to work.

Egg quality matters for everyone. For farmers, higher-quality eggs mean fewer losses from breakage or downgrading, which directly improves profitability. For consumers, stronger shells and better internal quality mean safer, fresher eggs and more reliable nutrition. For the environment, reducing egg waste helps lower the overall carbon footprint of production by making sure fewer resources are spent on eggs that never make it to the table.

Rainey’s work shows how relatively simple on-farm changes, such as adjusting egg collection time and considering hen age, can improve both food safety and overall production. Oviposition time, the time of day when the hen lays her egg, can influence how long the egg spends in the shell gland. Earlier eggs often have thicker shells and higher internal quality, making timing an important factor for farmers to consider.

To investigate these effects, Rainey studied two groups of hens: one younger (around 40 weeks old) and the other older (around 70 weeks). Eggs were collected twice each morning, once at 7:00 a.m. and again at 10:30 a.m., and analysed for external traits such as weight and shell thickness, as well as internal traits like albumen height, yolk quality, and bacterial populations.

Rainey reported three key takeaways:

1. Early-morning eggs were heavier, had thicker shells, and contained richer yolk and albumen.
2. Younger hens produced better-shaped eggs with stronger shells and higher albumen height.
3. Salmonella was detected among the samples, but its presence was not linked to laying time or hen age.

These findings provide useful direction for farmers, who can adjust egg belt run times or collection schedules to secure higher-quality eggs, and for the industry, which is continually seeking ways to reduce egg waste and improve efficiency. Future research could also explore nutrition strategies for older hens to maintain quality later in the production cycle.

As global demand for eggs continues to rise, research like Rainey’s helps build a food system that is safer, more efficient, and better for farmers and consumers alike.

This article summarizes research conducted by Alex Rainey as part of a BSc in Sustainable Agriculture. The original thesis, supervised by Dr. Victoria Murphy, was awarded second place in the BSAS Undergraduate Thesis of the Year competition (2024).