An excellent study and article from the Department of Poultry Science, North Carolina State University on the health benefits of free range eggs.
“Eggs from the range production environment had more total fat (P < 0.05), monounsaturated fat (P < 0.05), and polyunsaturated fat (P < 0.001) than eggs produced by caged hens. Levels of n-3 fatty acids were also higher (P < 0.05), at 0.17% in range eggs vs. 0.14% in cage eggs. The range environment had no effect on cholesterol (163.42 and 165.38 mg/50 g in eggs from caged and range hens, respectively).”