Utilization of Fruits by Product as Ruminant Feed: In Vitro Digestibility and Methane Production

Abstract

Food processing industries have been produced large amounts of waste consisting of peels, seeds, and some other fruit residues. Fruit peels contain phenolic compounds so it has the potential to be used as raw materials in the phytopharmaceutical extraction industry. This study aimed to evaluate the potential use of fruits by-products after the phenolic compound was extracted as ruminant feed by in vitro rumen fermentation analysis. The experiment was arranged in a randomized complete block design with 4 different fruits by-products (pomegranate peel (APGP), mangosteen peel (AMGP), kaffir lime peel (AKLP), and Melastoma candidum fruits (AMCF)) as treatments, and 4 different rumen mixture as a block. The results showed that AKLP had the lowest (P<0.05) crude fiber by 19.31%. Our results of TCI analysis showed that APGP (1.67) and AMGP (1.29) had higher TCI values than AKLP (1.18) and AMCF (1.02). Even though AMCF had the highest (P<0.05) protein content (9.33%) and crude fat (5.04%) but the potential gas production, SCFA, and gas production rate were lower compared with AKLP and APGP. AKLP had the highest (P<0.05) potential gas production (165.88ml), short-chain fatty acid (SCFA) (69.15mmol/dL), and gas production rate (0.07 ml/h). Methane was not detected in AMCF and AMGP. Only C2 and C3 were detected in the rumen fluid of MGP supplementation. In conclusion, AKLP and APGP were potentially used as ruminant feed.