Hen Well-Being &
Food Safety Timeline

See how the egg industry’s animal welfare, food safety and sustainability practices have grown over the years.


1910s & 1920s

Eggs were produced in backyards.

  • Hens ate whatever they found outside, which could cause harmful disease.
  • Weather, predators and parasites were challenges with hens outdoors.
  • Normal mortality rate was very high.
  • Eggs were gathered by hand.

Of the 76 million people in the U.S., 44% were farmers.


1930s & 1940s

Most eggs produced in small flocks of chickens in farmyards.

  • Approximately 150 eggs were produced per hen per year.
  • Hens sometimes laid eggs in their litter.
  • Disease was more prevalent with a greater likelihood for eggs to be contaminated by pathogens causing disease.

Cage systems were introduced, because research showed many benefits to moving hens indoors.


1950s & 1960s

While some farmers continued to use cage-free housing, use of cages became more popular.

  • Feeding practices improved hen health.
  • Indoor housing reduced parasite infections and disease spread from rodents.
  • Manure was separated from hens as it fell into storage under cages.
  • Separate conveyor belts carried away manure and eggs for processing.
  • Breeding programs improved disease resistance and egg-laying productivity. Overall, the hen mortality rate improved.
  • Innovation and improved equipment allowed egg farmers to better care for more hens, and flocks became larger.

1970s & 1980s

Standards for cleaning and inspecting eggs became more rigorous.

  • United States Department of Agriculture (USDA) Safety Inspection Service implemented a continuous audit program for all egg products made in the U.S.
  • Practices evolved to protect consumers from food-borne illnesses, based on science that showed eggs could be contaminated with Salmonella Enteritidis.
  • United Egg Producers (UEP) developed the first written expectations for hen care.


Various programs were implemented to improve egg safety.

  • FDA Egg Safety Action Plan reduced Salmonella Enteritidis infections associated with eggs through a series of recommendations by industry, consumer groups, and regulatory partners. Safe handling labels, requiring refrigeration of shell eggs, and the final adoption of the FDA Egg Safety Rule in 2009 -2010 were all elements of the Egg Safety Action Plan.
  • UEP initiated 5-Star Total Quality Assurance.
  • In 1999, UEP commissioned an independent Scientific Advisory Committee for Animal Welfare to review research on hen well-being, identify further research needs and recommend on-farm care standards.


  • Following the Scientific Advisory Committee recommendations, UEP launched the UEP Certified guidelines for hen care in conventional cage housing in 2002.
  • UEP Certified Cage-Free guidelines were developed in 2006.
  • The vast majority of eggs were produced in conventional cage housing.
  • As consumer interest in cage-free and organic eggs began to increase, some egg farms transitioned to meet demand.


  • A study completed by the Egg Industry Center demonstrates how the egg community reduced its environmental footprint over the last 50 years through improved hen feed, better disease control, and advancements in hen housing.
  • Egg farmers implemented more practices to prevent Salmonella Enteritidis with the FDA Egg Safety Final Rule effective in 2010.
  • To help answer hen housing questions and concerns of customers and egg producers, the Coalition for Sustainable Egg Supply conducted the most comprehensive research on hen housing to date.
  • The nation’s most devastating animal health crisis, high pathogen avian influenza, affected several Midwestern farms in 2015. Responding to the crisis, U.S. egg farmers have improved biosecurity and disease prevention measures.


  • Consumption of eggs in the U.S. is at an all-time high and egg farmers continue to implement both mandatory and voluntary on-farm safety programs.
  • Egg farmers are working diligently to balance high standards for egg safety, food affordability, environmental responsibility and hen well-being as they consider transitions in hen housing.
  • Many large food retailers have pledged to use only cage-free eggs by 2025.  Currently only 29% of egg production comes from cage-free hens.  Egg farmers are beginning to plan for this transition and will need to make a significant investment to construct cage-free barns.
  • Egg farmers continue to focus on continuous improvement in biosecurity to protect U.S. flocks.

For more statistics on current U.S. egg production, click here.