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Food, fibre and pharmaceuticals from animals
REVIEW

Nutritional implications of feeding reduced-protein diets to meat chickens

M. Hilliar https://orcid.org/0000-0001-7292-0007 A B and R. A. Swick A
+ Author Affiliations
- Author Affiliations

A School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.

B Corresponding author. Email: matthilliar@gmail.com

Animal Production Science 59(11) 2069-2081 https://doi.org/10.1071/AN19221
Submitted: 18 April 2019  Accepted: 12 June 2019   Published: 13 September 2019

Abstract

Global interest has emerged for the implementation of reduced-protein diets for meat chickens. The necessity of their development stems from environmental impacts and health and welfare concerns surrounding current meat-chicken production. Reduced crude-protein diets are possible with the increasing affordability of supplemental crystalline amino acids. Supplementing broiler feed with methionine, lysine and threonine is common practice in industry and has enabled a reduction of dietary crude protein to the levels currently used. However, further reduction of dietary protein often results in poor performance. Several nutritional options have been investigated with a focus on crystalline essential and non-essential amino acids such as glycine. However, reducing the crude protein of meat-chicken diets does change the ingredient and nutrient profile aside from the amino acid composition. Alterations in non-protein nitrogen concentrations, dietary electrolyte balance, minerals, fibre and carbohydrates, methyl-donors and polyphenols must be considered in formulations to ensure successful implementation of reduced-protein diets. The ability to maintain performance with reduced-protein diets may benefit sustainability and longevity of the meat-chicken industry.

Additional keywords: amino acids, broiler, crude protein, nitrogen, nutrition, sustainability.


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