In order to quantify the pressure of livestock feeding practices on biotic resources with Life Cycle Assessment (LCA), Papatryphon et al. (2004) developed a midpoint impact category called Net Primary Production Use (NPPU). It is expressed in kg of carbon by kg of product and is derived from the carbon-content of the feed ingredient, adjusted by its trophic level following the formula developed by Pauly and Christensen (1995). This dataset contains NPPU values for marine-fish-based, freshwater-fish-based, other-animal-based, plant-based and milk-based ingredients. The values aim to be used as standard in future studies. Different levels (Tiers) of specificity are proposed for the datasets, that use more detailed primary data, associated with more uncertainty in return.