Reduced-crude protein diets in chicken-meat production: justification for an imperative

SUMMARY

The justification for the chicken-meat industry to develop reduced-crude protein (CP) diets is compelling. Environment pollution by nitrogen and ammonia emissions can be improved, as a dietary reduction of 25 g/kg CP has been shown to generate a 25.8% reduction in N excretion. Bird welfare can be enhanced, as lower CP excretion improves litter quality and lessens the incidence of foot-pad dermatitis and related conditions. Flock health can be improved by reductions in the flow of undigested protein into the hindgut which, if unchecked, fuels the proliferation of potential pathogens at a time when in-feed inclusions of antibiotics are in decline. Moreover, reduced-CP diets have the potential to lessen feed ingredient costs as prices of ‘synthetic’ amino acids are likely to decrease due to economies of scale in production. The successful development and adoption of reduced-crude protein (CP) diets may reduce the chicken-meat industry’s demand for sources of ‘intact’ protein, e.g. where soybean meal is dominant and in demand from many quarters. Using synthetic methionine, lysine and threonine in maize-soy diets has been shown to lead to a substantial reduction in dietary CP from 356 to 200 g/kg, along with reductions in soybean meal from 709 to 293 g/kg feed. Reductions of 40% of soyabean use in feed have been postulated.

KEYWORDS:

• Amino acids
• ammonia
• chicken-meat
• footpad dermatitis
• reduced crude-protein (CP)
• nitrogen
• soybean meal

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

S. Greenhalgh

S. Greenhalgh has a Master of Animal Science (Animal Nutrition) from the University of Sydney and a Bachelor of Science (Zoology) from Western Sydney University. She is currently a PhD candidate at the University of Sydney looking at amino acid utilisation of reduced crude protein diets in chickens.

P. V. Chrystal

P. V. Chrystal completed his Bachelor of Science in South Africa under Professor Rob Gous in 1982 and is currently completing a PhD in poultry nutrition at the University of Sydney with Dr Sonia Liu and Dr Peter Selle, investigating reduced protein diets in broiler chickens. Peter has extensive commercial experience in both monogastric feeds and vitamin and trace mineral premix manufacture.  He has worked as a nutritionist for the largest poultry integrators in South Africa, New Zealand and Australia, where he currently works for Baiada Poultry, based in Sydney. Peter has presented at a number of conferences around the globe and been both author and co-author of several peer reviewed publications.

P. H. Selle

P. H. Selle is a veterinarian who was awarded a PhD in poultry nutrition in 2001 by The University Of Sydney and joined the Poultry Research Foundation the following year.In 2011 he was appointed as an Adjunct Associate Professor. Peter has been invited to speak at several international conferences and has published over 100 papers in peer-reviews journals since 1999.

S. Y. Liu

S. Y. Liu is a Senior Lecturer at the University of Sydney. Her current research interests include digestive dynamics of nutrients, nutritional geometry, sorghum in poultry diet, reduced protein diets and layer nutrition. Sonia has more than 100 scientific communications including >60 papers published in peer-reviewed scientific journals. She was the recipient of 2019 Australia Research Council Discovery Early Career Researcher Award and 2015 Science and Innovation Award for Young People in Agriculture.