Eggshell quality starts in the gut

Maintaining eggshell quality has become one of the most pressing challenges in modern poultry production. While older hens typically lay larger eggs, calcium deposition in the shell does not increase proportionally. The result is thinner shells, higher breakage rates, and more downgraded eggs, ultimately impacting profitability.

What’s becoming increasingly clear is that eggshell quality doesn’t start in the shell gland, it starts in the gut.

A smarter way to measure eggshell strength
Monitoring shell quality requires practical and repeatable tools. A non‑invasive eggshell assessment based on specific gravity now allows producers to evaluate shell quality without damaging the egg. Since eggshell density is the primary driver of egg specific gravity, this measurement closely reflects shell thickness and mechanical strength. Eggs with a specific gravity above 1.08 are considered high quality, while lower values indicate weaker shells2.
Because the method is non‑destructive, producers can monitor shell quality regularly throughout the laying cycle. Microscopic evaluations confirm that eggs with higher specific gravity also have more uniform and robust shell microstructures, validating specific gravity as a reliable indicator of eggshell strength.

The connection between the gut and the shell
So how does gut health influence eggshell quality?
Recent research highlights the role of lactic acid bacteria, such as Pediococcus acidilactici CNCM I‑4622 , in supporting this process. A 2025 meta‑analysis evaluating nearly 1,000 eggs across multiple trials found that hens supplemented with this bacterial probiotic showed a significant improvement in eggshell specific gravity. Only 9.9% of eggs fell below the quality threshold, compared to more than 30% in unsupplemented control birds1. 
Efficient calcium and phosphorus utilization depends on a healthy and functional gastrointestinal tract. When gut integrity and microbial balance are optimized, minerals are better absorbed, transported, and deposited where they matter most, strong eggshells.

Probiotics make a difference
Research shows that a bacteria probiotic influences mineral metabolism at a systemic level, increasing circulating concentrations of calcitriol and osteocalcin, both key hormones involved in calcium and phosphorus regulation2.
By supporting intestinal health and enhancing mineral assimilation, the probiotic helps ensure that dietary calcium is not just consumed but effectively utilized. This helps maintain normal shell mineralization and more consistent eggshell strength throughout extended laying cycles.

Supporting Longevity in Laying Hens
As producers look for ways to extend production cycles, maintaining eggshell quality is critical for sustainable success. Combining non‑invasive eggshell monitoring with targeted gut health solutions provides a powerful, proactive approach.
Explore how targeted digestive health solutions like Pediococcus acidilactici CNCM I‑4622 can support stronger shells, enhance mineral utilization, and steady laying performance.

Learn more on our U.S. poultry product page and see how our science‑backed solutions can support your operation.
 
References :
1 Schiavone, A., et al. Impact of Pediococcus acidilactici CNCM I-4622 Supplementation on Egg and Eggshell Quality Across the Laying Cycle: A MultiTrial Approach. Under publication, 2026.
2 Shanmugam, S., Barbé, F., Park, J.H., et al. “Supplemental Effect of Pediococcus acidilactici CNCM I-4622 Probiotic on the Laying Characteristics and Calcium and Phosphorus Metabolism in Laying Hens.” Scientific Reports 14 (2024): 12489. https://doi.org/10.1038/s41598-024-62779-5.