WLF has been developed to ensure gut health and carcass safety in all species. It is composed of calcium formate, citric acid and Phytomolecules protected in a lipid net-shape system, with “stop & go” release of the active ingredients in gizzard, small intestine, large intestine, colon and caeca, in particular, of formic acid in undissociated form. The usage of WLF is recommended in presence of severe field multifactorial challenge, risk of Salmonella, Clostridium perfringens and other pathogens.