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Effect of a Reduced Crude Protein, Amino Acid-Balanced Diet on Hen Performance and Ammonia Emissions

16 July 2013

Reduced crude protein, amino acid-balanced diets cut the costs of egg production in an experiment with commercial-scale laying hen flocks at Pennsylvania State University without detrimental effects on hen performance.

An investigation by researchers based at Pennsylvania State University sought to determine if reduced crude protein, amino acid-balanced laying hen diets could maintain egg production and quality while reducing feed costs or increasing farm revenue under commercial-scale conditions.

In Journal of Applied Poultry Research, H.K. Burley and co-authors at Penn State and A&E Nutritional Services report that they used a total of 50,760 Lohmann LSL Lite laying hens, divided into three groups that were each fed least-cost formulated corn-soybean meal-based diets from 18 to 51 weeks of age.

Diets contained low, intermediate or high (control) levels of crude protein and were supplemented with limiting amino acids.

Monthly replicated data collection included feed nutrient and particle size analyses, hen bodyweight, egg quality analyses and manure nutrient and ammonia (NH3) flux measurements for each dietary treatment. Weekly non-replicated data collection by the producer included egg production and grade-out data and feed cost and egg income reports.

Hen bodyweight, egg weight and egg quality (replicated data) did not differ significantly by level of dietary crude protein (P>0.05).

Egg production (non-replicated data) was similar across all diets.

Manure nutrients and ammonia flux also did not differ by dietary treatment.

Overall, the low and intermediate crude protein diets were less costly and resulted in greater revenue than the high crude protein (control) diet. Therefore, concluded Burley and co-authors, using reduced crude protein, amino acid-balanced diets for commercial-scale laying hen flocks would be economically beneficial - without sacrificing hen performance.


Burley H.K., P.H. Patterson, and M.A. Elliot. 2013. Effect of a reduced crude protein, amino acid-balanced diet on hen performance, production costs, and ammonia emissions in a commercial laying hen flock. J. Appl. Poult. Res. 22(2):217-228. doi: 10.3382/japr.2012-00609

Further Reading

You can view the full report (fee payable) by clicking here.

July 2013

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