Improvement of Fermentation and the In Vitro Digestibility Characteristics of Agricultural Waste-Based Complete Feed Silage with Cellulase Enzyme Treatment

Abstract

The use of crop residues and agricultural wastes in animal feed is a very common practice to ensure a feed supply in livestock production. However, the agricultural wastes generally have high crude fiber content. The study aimed at establishing the effects of increasing cellulase levels on fermentation quality, chemical composition, and in vitro nutrient digestibility of complete feed silage containing oil palm frond and rice crop residue. The mixture of ingredients (king grass, rice crop residue, oil palm fronds, cassava waste, tofu waste, and lactic acid bacteria) were treated with (A) cellulase 0 mL/kg as control, (B) cellulase 1 mL/kg, (C) cellulase 2 mL/kg, (D) cellulase 3 mL/kg, and (E) cellulase 4 mL/kg. The initial lactic acid bacteria (LAB) concentration in inoculant was 6.6 × 10 5 cfu/g of fresh matter, and the cellulase enzyme used in the study was a commercial product (Novozymes ). Plastic silos containing approximately 500 g of silage material for each were stored at room temperature (28-30°C) for 30 days. The results of the study showed that adding cellulase increased crude protein content (L: P < 0.01), but decreased neutral detergent fiber (NDF) (L, Q: P < 0.01), acid detergent fiber, hemicellulose (L: P < 0.01), and cellulose (L: P < 0.05) contents. The silages with cellulase treatment had high concentrations of lactic acid, but low pHs and total volatile fatty acid VFA contents, which indicated that they had been successfully preserved. Adding cellulase improved (L: P < 0.01) in vitro digestibility of dry matter, organic matter, and NDF. The study showed that adding cellulase improved fermentation quality and in vitro nutrient digestibility of agricultural and food industry-wastes based complete feed silage.

Effect of Some Feed Additives on In Vitro Rumen Digestibility

“…It was observed that cellobiohydrolase enzyme produced from Pichia pastoris yeast originating from Lentinula edodes fungus increased the cellulose digestibility of rice, wheat, and corn straws (Li et al, 2019). Santoso et al (2020) revealed that increasing cellulase doses increased the in vitro dry matter, in vitro organic matter, and NDF digestibility of silage made from agricultural waste (Table 1).…”

“…Recently, it has been reported that exogenous fibrinolytic enzymes increase the digestibility of feeds in in vitro rumen digestion studies (Kondratovich et al, 2019;Li et al, 2019;Santoso et al, 2020). Factors such as the mode of action of exogenous enzymes, the type of animal used, compatibility between exogenous enzymes, and rumen microflora affect the enzyme activity.…”

In vitro rumen fermentation characteristics of fermented complete feed based on rice straw with moringa leaves (Moringa oleifera) addition

“…For normal fiber degradation, rumen pH is around 6,0-7,0. At pH 6.2, the rate of microbes' degrading fiber activity will decrease [4]. The fermentation process on complete feed can reduce lignin content so that microbes can easily degrade feed.…”

“…A previous study showed that complete feed with rice straw levels of 25%, 30%, 35%, and 40% without fermentation produced 60.93-64.53% IVDMD, 62.92-65.56% IVOMD and 110.00-122.50 mM total VFA concentration. Complete feed with a 40% rice straw level resulted in the lowest IVDMD, IVOMD, and VFA total concentration [4]. Furthermore, there have not been many studies related to the effect of Moringa leaves on methane gas production.…”

“…The large quantities of those contents can reduce the feed palatability and interfere with rumen degradation. Fermentation is biotechnology commonly used to upgrade the nutritive values of poorquality feed [4].…”