Maggot Oil as a Feed Supplement for Reducing Methanogenesis of Rumen Microbial Culture In Vitro Anuraga Jayanegara, Dwitami Anzhany, Despal
Department of Nutrition and Feed Technology, Faculty of Animal Science, IPB University, Bogor 16680, Indonesia
Abstract
Hermetia illucens larvae or known as maggot contains considerable amount of oil in its body. The oil is rich in energy and C12:0 fatty acid (lauric acid), making it promising to be used as a multi-functional feed supplement. This experiment aimed to evaluate the use of maggot oil as a feed supplement for reducing methanogenesis of rumen microbial culture in vitro. Maggot was extracted for its oil by using hexane in a Soxhlet apparatus. The oil was supplemented into a feed substrate that consisted of forage:concentrate mixture (3:2 w/w). Supplementation was performed at different levels, i.e., 0, 1, 2, 3, 4 and 5% from substrate dry matter. An amount of 0.75 g substrate was mixed with 50 ml McDougall buffer solution and 25 ml rumen fluid (containing various rumen microbes such as bacteria, protozoa, anaerobic fungi and archaea methanogen) in a 125 ml serum bottle. All incubation bottles were tightly closed and incubated for 24 h in a water bath that maintained at 39oC. Each treatment was incubated in three replicates (duplo per replicate). Parameters measured were gas production kinetics, methane emission, volatile fatty acid (VFA), ammonia, protozoa population, and organic matter digestibility (OMD). Results revealed that maggot oil at 4 and 5% supplementation level was able to reduce methane emission by 20.7 and 26.9% (P<0.05) in comparison to control, respectively. However, its supplementation at 3% or lower did not alter the methane emission. The OMD parameter was linearly reduced with increasing level of maggot oil supplementation (P<0.05), but VFA was not affected. In contrast to our expectation, maggot oil at 3 to 5% increased log protozoa population and ammonia concentration than those of control (P<0.05). In conclusion, maggot oil may serve as a promising supplement for mitigating ruminal methanogenesis and the effect is dose-dependent.
