Home Page
Newsletter
Topics
Webcasts
More...
All articles about:
Research Summaries
Feed Management
Research Purpose
Several researchers have noted that when essential amino acid (AA) requirements are met, crude protein (CP) recommendations of NRC (1994) are not warranted. Little if any work has been done with turkeys, however, with consideration to loss of nitrogen (N) to the environment. Therefore, the current study determined if AA formulations of turkeys were warranted above NRC (1994) recommendations, and if lowering dietary CP by inclusion of 3 instead of 2 supplemental AA would result in measurable differences in N excretion.
Activities
A 2 by 2 factorial experiment was conducted to determine whether diets formulated with either two (Lys and Met) or three (Lys, Met, and Thr) supplemental AA to 100% or 110% of NRC (1994) AA recommendations would affect performance of turkey toms. Diets were formulated to maximize SBM inclusion when formulated with two supplemental AA thereby resulting in 2.0, 1.5, 1.4, and 1.0 %-units more CP than diets containing three synthetic AA at 4 to 8, 8 to 12, 12 to 16, and 16 to 20 wk of age, respectively.
What We Have Learned
Notably, no differences were noted in tom body weight, feed-to-gain, or breast yields in this study. N intake was affected by diet with birds fed 100% NRC AA consuming 144 g (7.3%) less N per 20 wk tom, than those fed 110% NRC AA. Similarly, birds fed 3 vs 2 supplemental AA consumed 154 g less feed N (8.4%) per 20 wk tom. These differences in N intake resulted in 0.8 kg more N in litter/pen (7%; P = 0.067) in birds fed 100 % NRC AA versus those fed 110% NRC. Similarly, birds fed three versus two supplemental AA had 1.24 less N in litter/pen (10.8%).
Why is This Important?
These data suggest that diets containing AA formulations above NRC (1994) recommendations do not provide any additional performance or P. major yield benefits, yet results in considerable increases in excreted N. In addition, formulation with three supplemental AA results in a sizeable reduction in N consumed and excreted.
For More Information
Contact us at: Todd Applegate, applegt@purdue.edu or (765)496-7769. For more information, read the following article:
Applegate, T.J., W.J. Powers, R. Angel, and D. Hoehler. 2008. Effect of amino acid formulation and acid supplementation on performance and nitrogen excretion in turkey toms. Poult. Sci. 87:514-520.
By Todd J. Applegate (Purdue University), W.J. Powers (Michigan State University), R. Angel (University of Maryland, and D. Hoehler (Evonik Degussa Corp.)
This report was prepared for the 2008 annual meeting of the regional research committee, S-1032 "Animal Manure and Waste Utilization, Treatment and Nuisance Avoidance for a Sustainable Agriculture". This report is not peer-reviewed and the author has sole responsibility for the content.
