Dr. Jacquie Jacob Ph.D., University of Kentucky
The nutritional requirements of laying hens will vary depending on level of production. Commercially, at least four diets are fed: one at peak production, one while production is still high, one post-peak, and one near the end of the laying period. This is done because the nutrient requirements change as the hen gets older. Using different diets maximizes diet efficiency, but is not essential for feeding a layer flock. Many flocks are raised using a single diet throughout the production period.
Nutritional requirements for commercial poultry production were developed based on the recommendations of the National Research Council (NRC, 1994). These recommendations were based on research completed before that time. Much has since changed in the genetics of the egg-laying hen, and the breeder companies have developed specific requirements for the genotypes they have developed. Many of the breeders have developed strains specifically for alternative production systems. The NRC (1994) recommendations may be applicable to some of the dual-purpose breeds of chickens used for egg production under organic systems.
Diet specifications for laying hens vary depending on their feed intake. Nutritionists typically take the recommended daily intake of a nutrient and divide it by the observed feed consumption to get the dietary concentration for that nutrient. The information in Table 1 is based on an average intake of chickens at different levels of production. It is not essential that several diets be fed, as the use of a single layer diet can be very successful.
Table 1. Nutrient requirements of egg-laying chickens
|NUTRIENT||PEAKING||POST PEAK||DECLINING||NEAR END OF LAYING PERIOD|
|Crude protein, %||16.50||15.23||14.55||14.22|
|Total sulfur amino acids, %||0.78||0.66||0.71||0.67|
|Available phosphorus, %||0.43||0.36||0.33||0.32|
|Linoleic acid, %||0.97||0.91||0.91||0.92|
Source: Hy-Line International (2014)
Note about methionine: The National Organic Program rules (United States Department of Agriculture [USDA], 2000) initially stated that synthetic methionine was a prohibited material for animal diets. An exemption was given to allow the industry to find alternatives. As research continued in this area, the National Organic Standards Board (NOSB) later recommended that, until October 1, 2012, the use of synthetic methionine be restricted—originally to 4 pounds per ton for laying hens, 5 pounds per ton for broiler chickens, and 6 pounds per ton for turkeys and all other poultry. After October 1, 2012, the allowed levels were decreased to 2 pounds per ton for laying and broiler chickens, and 3 pounds per ton for turkeys and all other poultry. For additional information, see the eOrganic article Synthetic Methionine and Organic Poultry Diets
§ 205.603 Synthetic substances allowed for use in organic livestock production.
In accordance with restrictions specified in this section the following synthetic substances may be used in organic livestock production:
(d) As feed additives.
(1) DL-Methionine, DL-Methionine-hydroxy analog, and DL-Methionine-hydroxy analog calcium (CAS #'s 59-51-8, 583-91-5, 4857-44-7, and 922-50-9)—for use only in organic poultry production at the following maximum levels of synthetic methionine per ton of feed: Laying and broiler chickens—2 pounds; turkeys and all other poultry—3 pounds.
Whatever feeding program used, it is important to make sure that all organic regulations are met. Since the use of synthetic methionine is restricted, modification of the diet may be required in order to meet the methionine requirements of the flock. When a poultry flock is raised outdoors, their increased activity may result in a slightly higher dietary energy requirement. This should be kept in mind when preparing the outdoor access area.
References and Citations
- Hy-Line. The Hy-Line redbook, an online management guide. 2014. [Online]. Hy-Line International. Available at: http://www.hyline.com/aspx/redbook/redbook.aspx (verified 25 Jul 2014)
- National Research Council. 1994. Nutrient requirements of poultry: Ninth revised edition. The National Academies Press, Washington, D.C. Available for purchase online at: http://www.nap.edu/catalog.php?record_id=2114 (verified 25 Jul 2014)
- United States Department of Agriculture. 2000. National organic program: Final rule. Codified at 7 C.F.R., part 205. (Available online at: http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=3f34f4c22f9aa8e6d9864cc2683cea02&tpl=/ecfrbrowse/Title07/7cfr205_main_02.tpl) (verified 25 July 2014)