Addition of essential oil source, Amomum compaction Soland ex Maton, and its effect on ruminal feed fermentation in-vitro

Abstract

Essential Oil (EO), as feed additive, is known to increase the feed efficiency and reduce the methane production among ruminants. This research was done to study the effect of Java cardamom (Amomum compactum Soland ex Maton) essential oil as feed additive on ruminal feed fermentation. The in vitro gas production technique was used in this research to determine the effect of cardamom on nutrient digestibility or fermentation in the rumen. Cardamom meal was added into the feed sample to get end concentration of EO in the fermentation medium as much as 0, 25, 50, 75 and 100 mg/L. The substrate consisted of Pennisetum purpureum, rice bran and wheat pollard. The addition of cardamom did not significantly affect the digestibility of dry matter except at 100 mg/L in which it decreased. Protein digestibility decreased when the diet was added with cardamom, whereas organic matter and crude fiber digestibility increased up to 13.5% and 24% level of EO100 mg/L, respectively. The production of volatile fatty acid (acetate, propionate, butyrate), pH and microbial protein synthesis except the ammonia concentration, were not affected by cardamom addition. Similarly, the methane production and protozoa population did not significantly change. The utilization of Java cardamom as feed additive positively affected the ruminal feed fermentation by increasing the organic matter and crude fiber digestibility and reducing the protein digestibility.