Geographical Variations in Egg Nutrient Density: A Comparative Study of Sustainable Layer Hen Systems in Ohio and Indiana in Late Fall and Early Winter Months

Regenerative, pasture-raised layer hen systems create synergistic relationships between the hens, forage, soil, and weather, fostering a sustainable system. However, the influence of these factors on egg nutrient profile and quality may vary by region. This study took place over two years; samples were collected from a farm in Ohio during the first year and a farm in Indiana during the second year. Egg (n = 12) and forage (n = 3) samples were collected monthly from September to December. Fatty acids were quantified using gas chromatography-mass spectrometry, micronutrients were assessed in a commercial laboratory, and carotenoids and polyphenols were analyzed colorimetrically. Ohio eggs had significantly darker yolks (average yolk fan score: 8.5 ± 1.8 vs. 3.9 ± 2.0; p < 0.0001), a higher beta carotene and carotenoid content, and a lower n-6:n-3 fatty acid ratio across the season. Indiana eggs had a lower average total phenolic content (0.07 ± 0.00 mg GAE/g vs. 0.14 ± 0.10 mg GAE/g) and lower average total cholesterol (5.35 ± 2.9 mg/g vs. 10.99 ± 1.54 mg/g). Forage composition and soil parameters varied between farms. Regional variations in forage composition, soil nutrients, and regional weather can significantly influence the nutrient density of eggs produced in sustainable, pasture-raising systems. This research highlights how local environmental factors can shape the nutritional profiles of eggs in different regions. Future studies should explore this relationship in more regions.