Granulated Animal Feed and Fuel Based on Sea Buckthorn Agro-Waste Biomass for Sustainable Berry Production

Abstract

The industrial harvesting of sea buckthorn (SBT) berries with twigs and subsequent pruning creates a large volume of lignocellulosic agro-waste. This study aimed to valorize this agro-waste as a raw material for animal feed and fuel granules, for developing a sustainable cascading SBT production scheme. Five SBT cultivars’ biomasses were characterized by analytical pyrolysis, mass spectrometry, and GC analysis. Condensed tannins, which are undesirable components for animal feed, were separated by extraction. The residue was analyzed for total protein, vitamins (A, C, and E), ash, crude fat, wood fiber, and macroelements (P, K, Ca, and Na), and showed great potential. The heavy metal (Cd, Hg, and Pb) content did not exceed the permitted EU maximum. Granulation regimes were elaborated using a flat-die pelletizer, KAHL 14-175. The digestibility and the amount of produced gas emissions were determined using in vitro systems that recreate the digestion of small ruminants. The investigation proved that SBT leaves and stems are a unique underutilized source of animal feed, used alone or in combination with others. Twigs, due to their thorns, were granulated and valorized according to standards for application as fuel. The scheme offered in this study enables SBT agro-waste utilization and sustainable SBT berry production.