While many in the egg industry press forward in support of the enhanced colony cage, the science behind the amount of space offered each chicken is lacking. National Association of Egg Farmers has science-based production guidelines available on a voluntary basis to its members. Below are the science-based research articles behind the production guidelines:
- 1.Adams, A.W. and M.E. Jackson,Effect of cage size and bird density on performance of six commercial strains of layers. Poultry Sci. 49:1712-1719.
- 2.Anderson, K.E. and A.W. Adams,Effects of rearing density and feeder and waterer spaces on the productivity and fearful behavior of layers. Poultry Sci. 71:53-58.
- 3.Anderson, K.E., A.W. Adams, and J.V. Craig, 1989. Behavioral adaptation of floor-reared White Leghorn pullets to different cage densities, cage shapes during the initial settling-inPoultry Sci. 68:70-78.
- 4.Anderson, K.E.,Welfare implications of cage density, population, and feeder space. 2001 Midwest Poultry Federation Convention, Touchstone EnergyâPlace at River Center, St. Paul, Minnesota, March 14-15, 2001, pp. 164-170
- 5.Anderson, K.E.Final Report of the Thirty-Fourth North Carolina Layer Performance and Management Test: Production Report. North Carolina Extension, Raleigh, NC Vol. 34, No. 4. November 2002.
- 6.Anderson, K.E., G.S. Davis, P. Jenkins, and A.S. Carroll. 2004. Effects of bird age, density, and molt on behavioral profiles of two commercial layer strains inPoult. Sci. 83:15-23.
- 7.Anderson, D.P., G.W. Beard, and R.P. Hanson,The adverse effects of ammonia on chickens, including resistance to infection with Newcastle Disease virus. Avian Diseases 8:369-379.
- 8.Anderson, D.P., R.R. Wolfe, F.L. Cherms and W. E. Roper,Influence of dust and ammonia on the development of air sac lesions in turkeys. Am. J. Vet. Res. 29(5):1049-1057.
- 9.Al-Rawi, B. and J.V. Craigt,Agonistic behavior of caged chickens related to group size and area per bird. Applied Anim. Ethol. 2:69-80.
- 10.Appleby, M.C.,Life in a variable world: Behavior, welfare and environmental design. Appl. Anim. Behav. Sci. 54:1-19.
- 11.Agriculture Canada. 1990. Recommended code of practice for the care and handling of poultry from hatchery to processingAgriculture Canada Publication 1757/E. Communications Branch, Agriculture Canada, Ottawa, Canada.
- 12.American Veterinary Medical Association.2000 Report of the AVMA Panel on Euthanasia. J. AVMA 218:669-696.
- 13.Bell, D.D., and D.R. Kuney. 2004. Farm evaluation of alternative molting procedures. J. Appl. Poult. Res. 13:673-679.
- 14.Bell, D.D., and W.D. Weaver, Jr.Commercial Chicken Meat and Egg Production. (5th Ed.) Kluwer Academic Publishers, Norwell, MA.
- 15.Biggs, P.E., M.E. Persia, K.W. Koelkebeck, and C.M. Parsons. 2004. Further evaluation of non-feed removal methods for molting programs. Poul. Sci. 83:745-752.
- 16.Brannigan, P.G. and J.B. McQuitty,The influence of ventilation on distribution and dispersal of atmospheric gaseous contaminants. Canadian Agricultural Engineering 13(2):69-75.
- 17.Burnett, W.E. 1969. Odor transport by particle matter in high density poultry houses. Poul. Sci. 48:182-185.
- 18.Carlile, F.S., 1981. Ammonia in poultry houses: A literature review. World’s Poul. Sci. 1:99-113.
- 19.Carpenter, G.A. 1986. Dust in livestock buildings-review of some aspects. J. Agric. Engng. Res. 33:227-241.
- 20.Craig, J.V. and A.M. Guhl, 1969. Territorial behavior and social interactions of pullets kept in large flocks. Poul. Sci. 48
- 21.Curtis, S.E. and J.G. Drummond, 1982. Air environment and animalIn CRC Handbook of Animal Productivity. Reichicigl, M. Ed. Vol. II, 107-118.
- 22.Consortium. 1999. Guidelines for poultry husbandry. In: Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. Federation of Animal Science Societies, Savoy, IL.
- 23.Denton, J.W., F.N. Reece, B.D. Lott. Effect of atmospheric ammonia on laying hen1982 Poul. Sci. 61:1815-1817.
- 24.Dearstyne, R.S., and P.H. Kime, 1943. Grazing crops for poultry. Extension Circular No. 239. NC Agricultural Extension Service, North Carolina State College of Agriculture and Engineering, Raleigh, NC.
- 25.Feddes, J.J.R., J.J. Leonard, and J.B. McQuitty, 1982. Heat and moisture loads and air quality in commercial broiler barns in Alberta. Research Bulletin 82-2, Dept. of Ag. Eng., Univ. of Alberta, Edmonton, Alberta, T6G 2G6, 82 pp.
- 26.Feddes, J.J.R., and J.B. McQuitty, 1983. Heat and moisture loads and air quality in commercial poultry laying houses in Alberta. Final Report for Engineering and Statistical Research Institute, Contract File No. OSU81-00304. Agriculture Canada, Ottawa, Ontario. 77 pp.
- 27.Jalal, M.A., S.E. Scheideler and D. Marx, 2006. Effect of bird cage space and dietary metabolically energy level on production parameters in layingPoul. Sci. 85:306-311.
- 28.Janni, K.A., P.T. Redig, J. Newman, and J. Mulhausen, 1984. Respirable aerosol concentrations in turkey grower buildings. 1984 Winter Meeting, ASAE, Hyatt Regency, New Orleans, LA, Dec. 11-14, 1984. Paper No. 84-4522.
- 29.Jones, T.A., C.A. Donnelly, and M.S. Dawkins, 2005. Environmental and management factors affecting the welfare of chickens on commercial farms in the United Kingdom and Denmark stocked at five densities. Poul. Sci. 1155-1165.
- 30.Jones, W., K. Morring, S. Olenchock, T. Williams, and J. Hickey. 1984. Environmental study of poultry confinement buildings. Am. Ind. Hyg. Assoc. J. 45(11):760-766.
- 31.Jull, M.A., 1951. Poultry Husbandry, 3rd Ed. McGraw-Hill Book Co., Inc. NY, NY
- 32.Kinder, Q.B., A.B. Stephenson, 1962. Floor space requirements of S.C. White Leghorns. Poul. Sci. 41:1394-1400.
- 33.Kling, H.F., and C.L. Quarles, 1974. Effect of atmospheric ammonia and the stress of Infectious Bronchitis vaccination on Leghorn males. Poul. Sci. 53:1161-1167.
- 34.Koelkebeck, K.W., C.M. Parsons, P. Biggs, and P. Utterback. 2006. Non-withdrawal molting programs. J. Appl. Poul. Res. 15:483-491.
- 35.Kristensen, H.H., and C.M. Wathes. 2000. Ammonia and poultry review: A review. World Poul. Sci. J. 56:235-245.
- 36.Lee, C.L., 1949. Profitable Poultry Management, 1949 ed. The Beacon Milling Co., Inc. Cayuga, NY, pp 106-119.
- 37.Loomis, E.C., J.R. Anderson, and A.S. Deal, 1980. Identification of common flies associated with livestock and poultry. Leaflet 2506. Univ. of California Cooperative Extension.
- 38.NRC. 1994. Nutrient Requirements of Poultry (9th rev. ed.). National Academy Press, Washington, DC. Water consumption of poultry (US gal/day/1000 birds).
- 39.Occupational Safety and Health Administration, US Department of Labor – Permissible Exposure Level for Ammonia, 29 CFR Sec. 1910.1000 Table Z-1 Limits for air contaminants.
- 40.Scheideler, S.E., and M.M. Beck. 2002. Guidelines for a non-fasting feeding program for the molting of laying hens. Univ. of Nebraska Coop. Ext. Bull. G02-1482-A.
- 41.Sohail, S.S., M.M. Bryant, S.K. Rao, and D.A. Roland, 2001. Influence of cage density and prior dietary phosphorus level on phosphorus requirement of commercial Leghorns. Poul. Sci. 80:769-775.
- 42.Stadelman, W.J., V.M. Olsen, G.A. Shemwell, and S. Pasch, 1988. Egg and Poultry-Meat Processing. VCH Publishers. NY, NY.