In vitro nutrient digestibility, volatile fatty acids and gas production of fermented palm fronds combined with tithonia (Tithonia diversifolia) and elephant grass (Pennisetum Purpureum)

This study aims to determine the effect of the addition of phosphorus minerals to palm fronds fermented with Phanerochaete chrysosporium mold on the digestibility of nutrient invitro and to evaluate the total gas production and concentration of volatile fatty acids in fermented palm fronds combined with elephant grass ( Pennisetum Purpureum ) and Tithonia ( Tithonia diversifolia ). This research was conducted with an experimental method through 2 experimental stages. Stage 1 consisted of 3 treatment doses of mineral P with 5 replications, namely: A = 1000 ppm, B = 1500 ppm and C = 2000 ppm. Stage 2 consisted of 4 combined treatments of fermented palm fronds (FPF) with elephant grass (EG) and tithonia (T with 4 replications, namely: A = 20% FPF + 80% (EG + T), B = 40% FPF + 60% (EG + T), C = 60% FPF + 40% (EG + T) and D = 80% FPF + 20% (EG + T). The ratio of EG and T is 4: 1. The parameters measured in stage 1 were the digestibility of dry matter, organic matter, crude protein, and crude fiber, while in stage 2 were gas production and total and partial VFA concentrations. The results of the research in stage 1 showed that the treatment had a significant effect (P <0.01) on the digestibility of dry matter, organic matter, crude protein, and crude fiber. Gas production and total and partial VFA concentrations at stage 2 also showed significant differences (P <0.01) between treatments. This study concludes that the addition of a P dose of 2000 ppm (C) in the fermentation process provides the highest nutrient digestibility value and the combination of 20% FPF and 80% (EG + T) (D) results in the highest gas production and VFA concentration.