KAJIAN PENGGUNAAN MINYAK IKAN LELE (Clarias sp) SEBAGAI SUPLEMEN UNTUK MENURUNKAN PRODUKSI GAS METAN RUMEN SECARA IN VITRO

DANANG NUR CAHYO, Prof. Dr. Ir. Lies Mira Yusiati, SU., IPU., ASEAN Eng.; Dr. Ir. Asih Kurniawati, S.Pt., M.Si., IPM.

2021 | Tesis | MAGISTER ILMU PETERNAKAN

Minyak ikan lele merupakan byproduct industri pembuatan tepung ikan lele yang potensial sebagai suplemen untuk menurunkan produksi gas metan rumen karena tinggi asam lemak tidak jenuh. Penelitian ini bertujuan untuk mengetahui pengaruh suplementasi minyak ikan lele terhadap populasi protozoa, produksi gas metan, produksi gas karbondioksida, aktivitas enzim karboksimetil selulase (CMCase), aktivitas enzim protease, parameter fermentasi rumen, kinetika produksi gas, profil asam lemak cairan rumen, keragaman metanogen rumen, dan kecernaan nutrien. Penelitian ini menggunakan rancangan acak lengkap (RAL) pola searah dengan 5 perlakuan dan 3 kali ulangan. Perlakuan terdiri atas T0 (Ransum kontrol), T1 (T0+2% BK (v/w) minyak ikan lele), T2 (T0+4% BK minyak ikan lele), T3 (T0+ 6% BK minyak ikan lele) dan T4 (T0+8% BK minyak ikan lele). Penelitian dibagi menjadi 2 bagian. Bagian pertama adalah analisis menggunakan in vitro gas production test berdasarkan metode dari Menke dan Steingass untuk mengamati populasi protozoa, produksi gas metan, produksi gas karbondioksida, aktivitas enzim CMCase, aktivitas enzim protease, pH, VFA total, VFA parsial, NH3, protein mikroba, produksi gas total, kinetika produksi gas, profil asam lemak cairan rumen, dan keragaman metanogen rumen. Analisis keragaman metanogen rumen menggunakan metode terminal restriction fragment length polymorphism (T-RFLP). Bagian kedua mengamati kecernaan in vitro protein kasar (PK), serat kasar (SK), bahan kering (BK), dan bahan organik (BO) pada inkubasi 48 dan 96 jam menurut metode dari Tilley dan Terry. Data penelitian bagian pertama dan kedua dianalisis menggunakan analisis variansi pola searah dan dilanjutkan dengan uji DMRT jika perlakuan berpengaruh signifikan. Data dari keragaman metanogen dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa suplementasi minyak ikan lele mulai level 2% sudah menurunkan populasi protozoa, dan produksi gas metan, tanpa menurunkan produksi gas karbondioksida. Suplementasi minyak ikan lele tidak berpengaruh signifikan (P>0,05) terhadap nilai aktivitas enzim protease, pH cairan rumen, VFA total, VFA parsial, protein mikroba, fraksi a, fraksi c, kecernaan PK 48 dan 96 jam. Suplementasi minyak ikan lele sampai dengan level 6% tidak menurunkan aktivitas CMCase, konsentrasi NH3, produksi gas, fraksi b, kecernaan BK, kecernaan BO, dan kecernaan SK, BK, BO 48 dan 96 jam, tetapi peningkatan suplementasi pada level 8% akan menurunkan nilai dari variabel tersebut. Suplementasi minyak ikan lele pada level 2% sudah menurunkan rasio asetat:propionat. Suplementasi minyak ikan lele tidak berpengaruh terhadap profil asam lemak cairan rumen, kecuali pada profil asam linoleat yang meningkat pada level suplementasi 4%. Suplementasi minyak ikan lele memberikan perbedaan terhadap keragaman metanogen rumen. Kesimpulan dari penelitian ini adalah suplementasi minyak ikan lele pada level 6% BK dalam ransum dapat menurunkan produksi gas metan rumen tanpa mengganggu proses pencernaan dalam rumen.

Catfish oil is a byproduct of the catfish meal production industry which is potential as a supplement to reduce rumen methane production because it is high in unsaturated fatty acids. This study aims to determine the effect of catfish oil supplementation on protozoa populations, methane production, carbon dioxide production, carboxymethyl cellulase (CMCase) enzyme activity, protease enzyme activity, rumen fermentation parameters, gas production kinetics, rumen fluid fatty acid profile, methanogens diversity. rumen, and nutrient digestibility. This study used a completely randomized design (CRD) with a unidirectional pattern with 5 treatments and 3 replications. The treatments consisted of T0 (control ration), T1 (T0 + 2% DM (v / w) catfish oil), T2 (T0 + 4% DM oil catfish), T3 (T0 + 6% DM catfish oil) and T4 (T0 + 8% DM catfish oil). The research was consists of 2 parts. The first part was an analysis using an in vitro gas production test based on the method from the Menke and Steingass to observe the protozoa population, methane production, carbon dioxide production, CMCase enzyme activity, protease enzyme activity, pH, total VFA, partial VFA, NH3, microbial protein, total gas production, gas production kinetics, rumen fluid fatty acid profile, and rumen methanogens diversity. Analysis of the diversity of rumen methanogens used the terminal restriction fragment length polymorphism (T-RFLP) method. The second part observed the in vitro digestibility of crude protein (CP), crude fiber (CF), dry matter (DM), and organic matter (OM) at 48 and 96 hours incubation according to the methods of Tilley and Terry. The first and second parts of the research data were analyzed using one-way analysis of variance and continued with the DMRT if the treatment had a significant effect. Data from methanogens diversity were analyzed descriptively. The results showed that catfish oil supplementation starting at the 2% level had reduced the protozoa population and methane production, without decreasing the production of carbon dioxide. Catfish oil supplementation had no significant effect (P> 0.05) on the value of protease enzyme activity, rumen fluid pH, total VFA, partial VFA, microbial protein, fraction a, fraction c, CP digestibility 48 and 96 hours. Catfish oil supplementation up to a level of 6% did not decrease CMCase activity, NH3 concentration, gas production, fraction b, DM digestibility, OM digestibility, and CF, DM, OM digestibility 48 and 96 hours, but an increase in supplementation at the 8% level reduced the value of these variables. Catfish oil supplementation at the 2% level has decreased the acetate: propionate ratio. Catfish oil supplementation had no effect on the fatty acid profile of the rumen fluid, except for the linoleic acid profile which increased at the 4% supplementation level. Catfish oil supplementation gave a difference to the diversity of rumen methanogens. The conclusion of this study is that catfish oil supplementation at the level of 6% DM in the ration reduced rumen methane production without having a negative effect to the digestive process in the rumen.

Kata Kunci : Catfish oil, Methane production, Rumen fermentation, Fatty acid profile, Nutrient digestibility, Rumen methanogen diversity