About this report:
The amount of corn and distillers grains (DDGS) in poultry diets is primarily determined by assessing the cost of providing essential nutrients and energy relative to other ingredients. With the de-oiling process in the production of distillers grains being common-place, use of DDGS will more likely depend on the provision of protein (amino acids) and less as a source of energy. The amino acid content of corn-derived protein is not well balanced for animal feeding. In a poultry diet, the main amino acid deficiencies in corn are corrected through the use of other protein sources (soybean meal, canola meal, etc.) and supplemental amino acids (lysine, methionine and threonine). Other supplemental amino acids (tryptophan and valine) are available commercially and could be used to balance amino acids in poultry diets containing a high amount of corn coproducts if such a need can be demonstrated. However, arginine is often limiting for growth as well and is not commercially available for use in poultry diets.
The overall objective was to determine if supplemental tryptophan and valine can be utilized in market turkey diets with a significant amount of corn protein present without causing a decline in performance.
The amino acids arginine and tryptophan where found to be co-limiting in poult starter diets with 20% DDGS. In grower type diets with 20% DDGS, valine appears to be limiting along with arginine and tryptophan. Utilization of commercially available supplemental valine and tryptophan in diets high in corn protein is limited by a lack of a commercially available arginine and potentially isoleucine. Dried distillers grains with solubles was found to decrease diet cost per ton of feed and to decrease cost per unit of gain in grower hen turkeys under the different cost scenarios explored in this report.
More research needs to be conducted to learn more of the inter-relationships of amino acids for turkey. While this study emphasized valine and tryptophan supplementation, isoleucine could also be potentially limiting in reduced protein diets.
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