An economic analysis of a methionine source comparison response model.

Methionine is the first-limiting amino acid in corn and soybean meal-based poultry diets. Therefore, its supplementation level is of primary economic importance to poultry production. The responses to the methionine sources dl-methionine (DLM) and methionine-hydroxy analog-free acid (HMTBA) have been compared using various methodologies. The so-called common plateau nonlinear model has been used to estimate relative bioavailabilities of the sources. This model has a coefficient that is used as a single value to compare the relative bioavailabilities of the sources for independent technical parameters like gain and feed efficiency. This model was used previously in a meta-analysis of published experiments and found 79 and 81% relative biological efficiencies of HMTBA for DLM for ADG and feed utilization efficiency, respectively. Because different sources would have different optimal feeding levels to maximize profits, we demonstrate the challenge of calculating a single optimal level for the different methionine sources. Further, we apply an economic analysis to results of the previous meta-analysis to demonstrate that the relative values of HMTBA and DLM for BW and ADG are between 81 and 86%, depending on the value of a broiler and the costs of feed and DLM.