Heliyon (Jun 2024)
Interaction of a source rich in phytonutrients (fruits peel pellets) and polyunsaturated oil (Tung oil) on in vitro ruminal fermentation, methane production, and nutrient digestibility
Abstract
Tropical fruit peels from mangosteen, rambutan, and banana are rich in phytonutrients. Several studies reported that the phytonutrients improved rumen fermentation. Nevertheless, the combination of phytonutrients and essential fatty acids on rumen fermentation have not yet been investigated. Hence, the aim of this research was to investigate the influence of fruit peel pellets (mangosteen, rambutan, and banana peel; MARABAC) containing phytonutrients and tung oil supplementation on rumen fermentation and the degradability of nutrients. Four levels of MARABAC (0, 2, 4, and 6 %) and four levels of tung oil (0, 2, 4, and 6 %) were supplemented with concentrate according to a 4 × 4 factorial arrangement in a completely randomized design (CRD). Rumen fermentation parameters, including gas production, ammonia nitrogen (NH3–N), volatile fatty acids (VFA), nutrient degradability (IVDMD and IVOMD), and in vitro methane (CH4) production were determined. The results showed that there were no interactions between MARABAC and Tung oil treatments for all terms of kinetic gas and cumulative gas, IVDMD and IVOMD, and in vitro ammonia-nitrogen (NH3–N). However, when combining MARABAC and tung oil beyond the 4 % level, VFA and in vitro CH4 production was severely affected. The supplementation of MARABAC and tung oil decreased gas production and rumen nutrient degradability (p < 0.05). Acetate (C2) and propionate (C3) production were significantly affected by the level of MARABAC supplementation. NH3–N was dropped when levels of MARABAC and tung oil supplementation were increased. There were interactions between MARABAC and tung oil on total VFA and in vitro CH4 production at 8 h (h). In addition, in vitro CH4 production decreased (p < 0.05) with higher levels of MARABAC supplementation. It could be concluded that MARABAC and tung oil supplementation significantly contributed to improving the production of gas and could be applied to decrease rumen CH4 production, thereby reducing the emission of greenhouse gases.
