Influence of Dietary Supplementation of Ensiled Devil Fish and Staphylococcus saprophyticus on Equine Fecal Greenhouse Gases Production

The present context was designed to investigate the efficacy of devil fish (DF; Plecostomus sp.) silage and Staphylococcus saprophyticus on fermentation characteristics as well as greenhouse gases production mitigation attributes in horses. Four levels of ensiled DF at 0 (control DF0), 6 (DF6), 12 (DF12), and 18 (DF18) % were added into the diet. Moreover, three doses of S. saprophyticus (0, 1, and 3 mL/g dry matter [DM]) were used for in vitro fecal fermentation. The use of ensiled DF resulted in increased (P < .0001) pH during fermentation. The asymptotic gas production was the highest (P < .0001) in DF6, whereas other supplementation caused lower production than that of control. Lag time for the asymptotic gas production decreased (P < .05) with increasing dietary DF doses. Inclusion of S. saprophyticus resulted in the lowest (P < .05) gas production and mL/0.5 g DM incubated and thus, the reduced gas production up to 23.17% than that of control. The interaction of DF × S. saprophyticus showed the lowest gas production at DF18, whereas the highest production was estimated at DF6 without S. saprophyticus after 48 hours. The lowest emission of CO₂ (P < .0001) was observed in DF18 inclusion, which was 15.25% lower than that of control at 48 hours of fermentation. In contrast, the lowest hydrogen (H₂) production was estimated in DF0, whereas DF18 exhibited the highest. Inclusion of DF12 and DF18 reduced (P < .05) methane (CH₄) emission by 58.24% and 59.33%, respectively. However, DF, S. saprophyticus, and DF × S. saprophyticus interaction had no significant effect (P > .05) on CH₄ production. In conclusion, ensiled DF and S. saprophyticus could be supplemented in equine diet as promising alternatives to corn for mitigating the emission of greenhouse gases effectively.