GAINESVILLE, Ga. — For the past couple of years, the price of eggs has been a hot topic across the United States. This affordable source of protein saw price increases in 2025. This time last year, USDA’s Agricultural Marketing Service reported that the national average price for large eggs was $8.15 per dozen.
However, in 2026, eggs have become more affordable compared to last year’s prices. According to data from the U.S. Bureau of Labor Statistics, the average price for a dozen Grade A large eggs as of January is $2.58, more than half the price of the recorded peak price in March 2025.
While a lot of things can affect the price of eggs, such as bird flu and supply chain issues, it all goes back to the hen. Researchers from the University of Hawai’i at Mānoa’s College of Tropical Agriculture and Human Resilience recently investigated how hens age to better understand how that can affect egg production and quality, and therefore prices.
In their prime, about 97 percent of high-performing hens lay eggs. In fact, hens known as “long-layers” produce 500 eggs by 100 weeks of age, Md Ahosanul Haque Shahid, Rajesh Jha, and Birendra Mishra, authors of the study, noted. Despite this large number of eggs being produced for an extended period of time, there is concern surrounding the steady decline of eggs produced after the 40-45 weeks of age mark.
“A farmer is losing roughly 20-22 percent eggs, but still providing expensive feed to the chickens,” Shahid, a PhD student in the Department of Human Nutrition, Food and Animal Sciences and the study’s lead author, said in an article published by the University of Hawai’i. “We are trying to minimize those costs to help farmers survive financially.”
Although the number of eggs is lower as hens age, the eggs become larger as hens get older. While this can be seen as a positive for farmers and the industry, the size of an egg isn’t a top priority.
Laying hens start laying eggs between 18 and 20 weeks of age, with their peak occurring around 30 weeks. The timing of when the hens begin laying eggs is important because eggs are more valued once a certain weight threshold is met. Timing and age also matter because as hens get older, certain bodily functions begin to change, which ultimately affects the eggs.
“As hens get older, their energy allocation processes, along with hormonal and enzymatic responses, may become less effective,” Shahid et al. (2025) said in the study. “This can lead to an increase in inhibitory factors and reduced activity in the hypothalamus, which can cause weight loss, decreased oviduct function, increased pause days, and defective eggs.”
Another aspect that is important to egg production is a hen’s gut health. In fact, research shows that a healthy microbiome is linked to overall health and that higher early-life body weight correlates with increased egg production later in life, Shahid et al. (2025) noted.
Unfortunately, there is currently limited corresponding data on the gut microbiome and its functional activity in layer hens across various ages, Shahid et al. (2025) added.
With that in mind, it’s understandable that the researchers would focus on the investigation of the cecal microbiota, predicted metabolic pathways, and ileal gene expression to explain how gut health, nutrient availability, and physiological status can alter egg production in laying hens across different ages.
To complete this study, the researchers collected cecal digesta and ileal tissues from euthanized laying hens at peak production, mid-decline, and decline-phase. The cecal digesta and ileal tissue samples were taken specifically because of their significance for gut health.
Production phases
Peak production is 37 weeks, mid-decline is 67 weeks, and decline-phase is 87 weeks, Shahid et al. (2025) specified. In the past, other studies have only focused on the early and mid-production phases of laying hens, but the industry is gradually extending production cycles to 100 weeks and beyond. This means that there is a critical knowledge gap regarding the dynamics of the microbiome during the late production phase, Shahid et al. (2025) explained.
Hy-Line-W36 hens used for the study came from a local layer farm on Oahu Island, so the results of the study are specific to the island’s environmental conditions, the study’s authors noted. However, the implications of the study could be global.
Once the samples were taken, they were immediately snap-frozen at minus 80 degrees C (minus 144 degrees F), then 8 samples from each production group were selected based on visual confirmation of the uncalcified egg’s position in the uterus to ensure data consistency and reduce bias, Shahid et al. (2025) stated.
“This also minimizes variability due to transcriptional activity and enzyme function, highlighting age- or production-phase-related physiological changes rather than oviductal-stage effects,” Shahid et al. (2025) further explained.
After the samples were tested and sequenced, Shahid et al. (2025) found that:
- The consistent dominance of different microbial groups across multiple taxonomic levels highlights microbiome dynamics associated with aging.
- The enzyme functions in the cecal microbiome shifted significantly with age.
- And, the ileal expression of solute carriers and calcium channels varied with age.
Additionally, the study’s authors found that, as hens age, the support provided by microbes shifts from high-efficiency production to maintenance-oriented functionality, which may contribute to the observed decline in egg numbers in hens aged 87-weeks and older.
“This study reveals a clear age-associated shift in gut microbial diversity, as well as functional enrichment of metabolic pathways and enzymes, and gut health indicators,” Shahid et al. (2025) said. “This study demonstrates that gut microbial composition and predicted microbial functions in laying hens are highly age-responsive and undergo coordinated transitions across the laying cycle.
“Overall, these findings highlight a dynamic interplay between aging, gut microbiota, and host intestinal function that shapes egg performance,” Shahid et al. (2025) added.
The information found in this study could be essential for creating dietary and management strategies to improve flock health and possibly boost production by 1 or 2 percent.
“That 2 percent makes a huge difference because you’re talking about tens of thousands of chickens,” Shahid said. “It’s a tremendous amount of affordable protein that can feed thousands of families.”
In the end, that’s what this study was aiming to do: learn more about how hens age to keep an affordable, high-quality protein available to families in this era of fluctuating prices.
