Nutrient Requirements of Poultry
A NEW STUDY TO UPDATE THE NUTRIENT REQUIREMENTS OF POULTRY
Reports on the nutrient requirements of animals are developed by the National Academy of Sciences, Engineering, and Medicine (formerly, the National Research Council-NRC) and published by the National Academies Press. Since the mid-1900s the Academies have released reports on the nutrient requirements of various species, including poultry, swine, dairy cattle, beef cattle, horses, dogs, cats, and fish. A committee of experts is appointed to develop each of the publications. This process ensures that information published in NRC reports is unbiased and of the highest technical quality.
The ninth edition of the Nutrient Requirements of Poultry (NRC Poultry) was published in 1994 and is widely used in the USA and throughout the world. However, strains of birds and feeding practices have changed dramatically during the last 17 years and a great deal of new research has been published. Consequently, some of the material in the 1994 edition has become outdated, and there is an urgent need to develop a new Poultry report.
Improved Strains and Other Genetic Changes
Rapid changes in the genetic lines of broilers, layers, and turkeys have led to large improvements in performance. Growth, breast meat deposition, and laying rates have increased significantly during the last 20 years, changing nutrient needs. The requirements defined in the current Poultry NRC are for birds from almost 20 years ago and need to be revised. Major segments of the industry are not currently following the NRC Poultry requirements because many of the requirements underestimate the needs of the current strains.
New Feed Ingredients
Many new feed ingredients are now available to the poultry industry. Considerable quantities of coproducts from the biofuels industry, such as dried distillers’ grains with solubles, are produced and may be incorporated into poultry diets. Other ingredients such as specialized soy products and corn varieties selected for high lysine and high oil contents need to be reflected in the feed database. Some of these ingredients have large variations in their nutrient profiles.
Digestibility and Bioavailability and True Metabolizable Energy Values
Many ingredients, especially coproduct ingredients, vary considerably in nutrient bioavailability. Current tables of amino acid digestibility and true metabolizable energy need to be updated. Text that describes the importance of bioavailability needs to be updated. Requirements for key nutrients such as amino acids and phosphorus need to move toward listing on a digestible and/or bioavailable basis.
Nutrition and Immunity
Current knowledge of the role of nutrition on immunity, health, and the gut environment has increased significantly and the body of information in the literature needs to be captured and summarized. This includes the roles of trace minerals and vitamins nutrition on health and immunity.
Effect of Nutrition on Product Quality
New research has indicated that nutrition can have significant effects on the quality of the product. For example, the content of nutrients such omega-3 fatty acids, lutein, and vitamin E in eggs can be altered by changes in diet composition of the hens. The shelf life of products can be altered by changes in nutrition of the birds. A review of these types of effects is needed and should include discussion of some nutrients, such as lutein, where a specific requirement has not been established.
Different Management Systems
Poultry are housed and managed in a variety of ways (e.g., caged vs. free-range layer). The management system can have effects on requirements for some nutrients.
Feeding to Reduce the Environmental Impact
There is now a much greater concern about the effect of various industrial activities, including those of agriculture, on the environment. The role of nutrition and management of poultry to reduce air and water pollution needs to be included in the new Poultry update. An authoritative, unbiased review of all these issues is needed. For example, methods to reduce phosphorus and nitrogen excretion by the use of phytase and supplementation with crystalline amino acids should be discussed.
Statement of Task
The National Academies of Science, Engineering, and Medicine proposes to undertake a study to develop a new report on the nutrient requirements of poultry. The draft statement of task (SOT) for the proposed study (which will become the guiding document for the committee experts appointed to undertake the study) is as follows:
An expert committee will prepare a report that reviews the scientific literature on the nutrition of poultry and makes recommendations on nutrient requirements. All life phases and types of production will be addressed. New recommendations will be made with consideration for the increased performance of different types of poultry, including broilers, turkeys, laying hens, and ducks with updates to additional species, as appropriate. The report will include a comprehensive analysis of recent research on feeding and nutrition of poultry including new research on the amounts of energy, amino acids, lipids, minerals, vitamins, lipids, and water needed by poultry; a summary of the composition of feed ingredients, mineral supplements, and feed additives routinely fed to poultry; information about variability in feed ingredients sourced from different regions; and, information about feed ingredients from the biofuels industry and other new ingredients (e.g., novel soybean products). The report will examine requirements for digestible phosphorus and amino acids and update concentrations of digestible phosphorus and amino acids in feed ingredients, examine new information about nutrient metabolism and utilization and provide a review of nutritional and feeding strategies to minimize nutrient excretion. A discussion of the effect of feeding on the nutritional quality of poultry meat and eggs will be included. Effects of the environment, feed management, and other production aspects on nutrient requirements, including antibiotics and their alternatives, will be addressed. In addition, quantitative information on requirements will be incorporated, as well as new information on bioavailability of various nutrients. This revision also will include mathematical equations that reflect the biologic basis for predicting requirements and performance based on nutrient input-production response relationships. Depending on the extent of new information available, a computer model may be developed that incorporates these mathematical equations. Future areas of needed research also will be identified.