Editing Free-range eggs (section)

==Nutritional content==
Differences in age, strain, and nutrition of the hens make it exceedingly difficult to draw scientific conclusions about the effects of housing systems on the quality of the eggs. Consumer perceptions of these alternative systems delivering a better product are then scientifically unjustified in terms of there being any nutritional difference.<ref>{{cite book|editor-last1=Nys|editor-first1=Yves|editor-last2=Bain|editor-first2=Maureen|editor-last3=Immerseel|editor-first3=Filip Van|title=Impossible the safety and quality of eggs and egg products|date=2011|publisher=Woodhead|location=Cambridge|isbn=978-0857093912|pages=318–319}}</ref> A 2011 research study carried out in North Carolina compared free-range and conventional caged eggs for fatty acids, cholesterol, vitamins A and E, finding higher fat content in free-range eggs, and no significant difference in cholesterol and vitamin levels.<ref>{{cite journal|last1=Anderson|first1=K. E.|title=Comparison of fatty acid, cholesterol, and vitamin A and E composition in eggs from hens housed in conventional cage and range production facilities|journal=Poultry Science|date=14 June 2011|volume=90|issue=7|pages=1600–1608|doi=10.3382/ps.2010-01289|pmid=21673178|doi-access=free}}</ref> Vitamin D in eggs have been observed to increase up to 4 times in hens that have exposure to sunlight, compared to hens that are kept away from sunlight.<ref>{{cite journal|last1=Kühn|first1=Julia|last2=Schutkowski|first2=Alexandra|last3=Kluge|first3=Holger|last4=Hirche|first4=Frank|last5=Stangl|first5=Gabriele I.|title=Free-range farming: A natural alternative to produce vitamin D-enriched eggs|journal=Nutrition|date=1 April 2014|volume=30|issue=4|pages=481–484|doi=10.1016/j.nut.2013.10.002|pmid=24607306|language=en|issn=0899-9007}}</ref> Another research suggests that grass fed hens can produce eggs that are rich in (n−3) fatty acids, without adverse oxidative effects.<ref>{{cite journal|last1=Lopez-Bote|first1=C.J|last2=Sanz Arias|first2=R|last3=Rey|first3=A.I|last4=Castaño|first4=A|last5=Isabel|first5=B|last6=Thos|first6=J|title=Effect of free-range feeding on n−3 fatty acid and α-tocopherol content and oxidative stability of eggs|journal=Animal Feed Science and Technology|date=May 1998|volume=72|issue=1–2|pages=33–40|doi=10.1016/S0377-8401(97)00180-6}}</ref> Some other non peer-reviewed studies have found evidence for nutritional benefit of free-range eggs.<ref>Jull, Morley A. ''Successful Poultry Raising.'' 1943</ref><ref>Karsten, Heather. "Pasture-ized Poultry." ''Penn State Online Research," May 2003. http://www.rps.psu.edu/0305/poultry.html {{Webarchive|url=https://web.archive.org/web/20060901063244/http://www.rps.psu.edu/0305/poultry.html |date=1 September 2006 }}</ref><ref>Long, C. and Newbury, U. "The Good Egg." ''Mother Earth News,'' August/September 2005. http://www.motherearthnews.com/DIY/2005-08-01/The-Good-Egg.aspx</ref><ref>Long, C. and Alterman, T. "Meet Real Free-Range Eggs" ''Mother Earth News,'' October/November 2007. http://www.motherearthnews.com/Whole-Foods-and-Cooking/2007-10-01/Tests-Reveal-Healthier-Eggs.aspx</ref>