Recently a new meta-analysis, result of the collaboration between UC Davis university (USA) and Adisseo, has been published in Poultry Science in April 2022: Evaluating growth response of broiler chickens fed diets supplemented with synthetic DL-methionine or DL-hydroxy methionine: a meta-analysis, M.E. Uddin, Henk J. van Lingen, Paula G. da Silva-Pires, Dolores I. Batonon-Alavo, Friedrich Rouffineau, Ermias Kebreab. The study was presented also at Poultry Science Association Annual Meeting in San Antonio (USA).
Compared to the existing meta-analysis, this new meta-analysis benefits from 4 main improvements:
The application of more complex and powerful mathematical models allows to cope with data variability and to better predict animal’s response to Methionine sources.
The use of sulfur amino acids intake as explanatory variable, instead of Methionine dose (%) to cope with the discrepancy in feed consumption
A focus on data below the breakpoint of dMet and dSAA, where there is most likely a chance to find difference if any
Data sources from 1985 to 2019
Flowchart of the modeling steps followed in the meta-analysis:
Results obtained with the linear-plateau and the quadratic-plateau are considered.
The conclusion is:
–>Using powerful meta-analysis approach including the most recent studies, no significant difference was detected in the weight gain in response to DL-Met and OH-Met at or below the requirement.