Extensive Literature Search on the bioavailability of selected trace elements in animal nutrition: Incompatibilities and interactions
The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the Authority is subject. It may not be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.
The main objective of this Extensive Literature Search (ELS) was to identify the bioavailability of trace element (Co, Cu, I, Fe, Mn, Mo, Se, and Zn) additives and their incompatibilities and interactions, in particular when combined with other feed additives or components of the animal diet. Different search chains were performed for each one of the elements in the most important scientific databases (i.e., PubMed, Scopus and ISI Web of Knowledge), and the resulting references were managed by using the open-source reference tool DistillerSR© systematic review software. The ELS process is based on several consecutive screening steps to accurately select articles which comply with the inclusion criteria. Identification and removal of duplicates were executed in 2 steps: one based on the title and abstract, and the following one according to the full text. In order to avoid the loss of key papers, each selection was performed by duplicate. A database in MS Excel format, recording the most important items derived from the selection process, was obtained. In general terms, the ELS protocol allowed retrieving a high number of manuscripts from the most commonly used databases, performing an accurate selection of articles, and therefore accomplishing with the aims of the study. Data quality from all references was assessed by means of responding a brief questionnaire with 10 questions, which assured the appropriateness of the citations. Most papers answered data quality questions well, with the exception of the justification of the sample size, which was only correctly addressed in a reduced number of articles (<10%).