Evaluation of agro-industrial by products as potential local feed for ruminant animals: volatile fatty acid and NH3 concentration, gas production and methane emission

Abstract

Abstract Due to high cost of conventional feed, the use of agro-industrial by products has been widely known as alternative for animal feed. The aims of this experiment is to get information about the potency of agro-industrial by product in Aceh that can be utilized as feed for ruminant animals based on volatile fatty acid concentration, gas production and methane emission. Eight kinds of agro-industrial by product in Aceh from three different location products (sago residues, coconut meal, soybean-ketchup by product, coffee pulp, cacao pod, sago tree, corncob, and rice brand) were used in this study. Prior to analyses, all samples were dehydrated at the temperature of 60°C for 24 h, then crushed to pass a 1 mm sieve. Crushed samples were analysed to determine volatile fatty acid concentration, gas production and methane emission. Incubation was carried out in water bath with three replicates for 48 h with the temperature of 39°C. The production of gas was collected and periodically documented at 2, 4, 6, 8, 12, 24, 36 and 48 h after incubation by using a syiringe. The VFA production from agro-industrial by products in this study was not significantly different (P>0.05) from one by-products and others from 83±2.26 mmol/l for cacao pod to 123 ±16.1 mmol/l for coffee pulp. The production of NH3 was with the range of 5.72 mmol/l to 15.71 mmol/l for for sago trees and coconut meal respectively. Total gas production from agro-industrial by products was 69.90 ml g/DM to 210.40 ml g/DM with methane gas production in the range of 33,88 – 35.18 ml/g DM after agro-industrial by products were incubated for 48 h. In conclusion, based on the fermentation parameters in this study, local agro-industrial by products in Aceh Province can be utilized as sources of alternative animal feed as replacement of conventional. Based on fermentation parameters measured in this study (VFA, NH3, gas production total) were still in optimal range for fermentation process in animal production