421 Inherent Livestock Feed Production: Abundance of Non-Edible Biomass in the Agricultural and Processing Sector in Germany

Abstract

Abstract Livestock have a central role in food production as extractors and concentrators of nutrients from non-edible biomass [neB] producing high value foodstuff for human nutrition [1]. Agricultural production aims for maximizing edible biomass [eB] production whereby, neB production is inevitably coupled to it. The goal of this study was to determine how much neB and eB is produced annually in agricultural and processing sector in Germany. Literature research has been conducted (26 peer-reviewed publications, 15 books, 26 reports, 15 other grey literature) to identify the amount of eB and neB along the agricultural production chain in Germany. Therefore, conversion efficiencies of biomass from field to fork have been calculated on a dry matter basis by considering main- to by-product ratios on the field as well as processing efficiencies for food and renewable energy industry branches (e.g., milling, ethanol production, brewing, oil extraction, starch extraction, sugar extraction). Based upon these calculations, the human edible fraction (HeF) [2] was used together with mean agricultural production data (2012-17) in Germany to determine the abundance of eB and neB for two scenarios: low vs. high edibility of biomass. Since HeF factors denote theoretical margins of edibility of biomass, additional scenarios were calculated assuming current processing efficiencies as well as silage maize being completely inedible. Furthermore, changes in biomass production in scenarios of complete substitution of land used for silage maize production and cultivation of human edible foods have been analysed.115 to 134 million tons of neB and 38 to 57 million tons of eB were produced annually during the observation period. This equals 2-3.5 kg of neB per kg of eB. When silage maize was considered as neB, numbers increased to 2.5 to -4.8 kg of neB per kg of eB. When current processing efficiencies in Germany and grain usage were used for calculations instead of the two HeF scenarios, and silage maize was considered not edible, then 1kg of eB produced 4kg of neB. When the used area for silage maize cultivation would in future be substituted for food crop cultivation then 1kg of eB yielded 2.8kg of neB. The scenarios suggest that the amount of eB per acre of agricultural land changes dramatically once the whole agricultural system including grassland, green plants for feed production, straw, and by-products is adapted to future scenarios. The future challenge will be to improve current processing efficiencies of the food and renewable energy industry to approach the upper limits of edibility given by the HeF fractions. In any case, feed production is inherent.[1] Bradford et al. (1999) Ames, IA (Task force report / Council for Agricultural Science and Technology, 135) ISBN 1-887383-17-4[2] Ertl et al. (2015) In: Agricultural Systems 137, S. 119–125. DOI: 10.1016/j.agsy.2015.04.004.