Paper ID: 87
THE EFFECTS OF CATFISH OIL SUPPLEMENTATION AS UNSATURATED FATTY ACID SOURCE ON BALI COW GAS PRODUCTION KINETICS, IN VITRO DRY MATTER DIGESTIBILITY, AND IN VITRO ORGANIC MATTER DIGESTIBILITY IN VITRO
Danang Nur Cahyo1, Lies Mira Yusiati1*, Asih Kurniawati1, Chusnul Hanim1, Muhlisin1
1Department of Feed and Animal Nutrition, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta, Indonesia
Catfish oil (CFO) was a byproduct of catfish meal, which has high proportion of unsaturated fatty acids. The purpose of this study was to investigate the effects of catfish oil supplementation on gas production kinetics, dry matter, and organic matter digestibility in vitro with Bali cow rumen fluid. The materials used in this study consisted of Bali cow rumen fluid as inoculum, and treatment diets. The design of this study was a completely randomized design with 5 treatment consist of T0 (control diet: Pennisetum purpupoides (60%): wheat pollard (40%): soybean meal (10%)), T1 (T0 + 2% DM CFO), T2 (T0 + 4% DM CFO), T3 (T0 + 6% DM CFO), T4 (T0 + 8% DM CFO) and 3 replication. Gas production technique described by Menke and Steingass was used in this study with 48 hours of incubation time. Gas produced at 0, 2, 4, 8, 12, 24, 36, 48 hours after fermentation were recorded. Gas production kinetics was analyzed by Fit Curve application. The result showed that CFO supplementation at the level of 8% significantly (P<0,05) decreased total gas production, b fraction value, in vitro dry matter digestibility (IVDMD), and in vitro organic matter digestibility (IVOMD), but there were insignificant (P>0,05) effect on a and c fraction value. It could be concluded that supplementation catfish oil at the level of 6% DM in the Bali cow diet did not give a negative effect on rumen substrates degradation.
It seems that gas production, IVDMD, and IVOMD decreased as the levels of CFO increased. The author explained that oil may decrease the fiber digestibility blocking the fiber-degrading enzyme. Please kindly explain the mechanism in more detail. Thank you
Thank you for the question Mr. Adi
Let me answer the question that you ask.
There were two main mechanisms correlated with “how the oil decreased the fiber digestibility?”
The first had been mention in the previous slide, that the oil could interfere rumen microbes so affecting its activity, especially in fiber degradation.
The second is the mechanism you asked. As we know, rumen selulolytic microbes secreted cellulolytic enzymes to degrade fiber into its simpler component, then its continued until the fiber becomes its monomer, and the microbes used that for further process.
To understand how cellulase enzyme degraded the complex structure of feed fiber components, we have to remembered the enzyme working mechanism. Active side of cellulase enzyme need to bond with the substrates, which is fiber to cleave the fiber, but in this situation, high level of oil supplementation made the oil surrounding the fiber component so its unable for enzyme create a bond with the substrate, and lead to reducing of fiber digestibility.
I hope my answers match your expectations
Thank you for asking
Best regads, Danang