Pengujian Ransum Kerbau Berbahan Baku Sorgum Sebagai Sumber Serat Secara In Vitro dan In Sacco

Sorgum merupakan salah satu tanaman sumber serat untuk kebutuhan ransum kerbau yang potensial dikembangkan di Indonesia. Sorgum varietas Samurai 1 dan samurai 2 masing-masing merupakan hasil pemuliaan melalui mutasi radiasi yang berasal dari indukan sorgum varietas Pahat. Penelitian ini dilakukan untuk mengetahui potensi ransum yang mengandung sorgum samurai 2 sebagai sumber serat dibandingkan dengan ransum yang mengandung sorgum pahat dan bagas sorgum samurai 1. Potensi yang diamati adalah pengaruhnya terhadap laju pertumbuhan mikroba rumen kerbau ( in vitro ) dan degradasi bahan pakan ( in sacco ). Rancangan acak lengkap dengan 6 perlakuan dan 3 ulangan diterapkan dalam percobaan ini. Enam ransum yang diuji adalah: P1 (50% jerami sorgum pahat + 50% konsentrat), P2 (50% silase jerami sorgum pahat + 50% konsentrat), P3 (50% jerami sorgum samurai 2 + 50% konsentrat), P4 (50% silase jerami sorgum samurai 2 + 50% konsentrat), P5 (50% bagas sorgum samurai 1 + 50% konsentrat) dan P6 (50% silase bagas sorgum samurai 1 + 50% konsentrat). Peubah yang diamati adalah pH, konsentrasi amonia (NH 3 ), Total Volatile Fatty Acid (TVFA), sintesis protein mikroba (teknik radioisotop 32 P), degradasi Bahan Kering (BK), karakteristik degradasi BK, degradasi Neutral Detergent Fiber (NDF) dan karakteristik degradasi NDF. Hasil yang diperoleh menunjukkan bahwa konsentrasi NH 3 , laju pertumbuhan bakteri rumen dan degradasi NDF tertinggi dihasilkan ransum P4 dengan nilai masing-masing 24,87 mg/100 ml; 8,11 mg/2 jam/100 ml dan 31,96%. Konsentrasi TVFA dan pH antar perlakuan tidak berbeda nyata. Keenam perlakuan ransum mampu mendukung fermentasi dan kecernaan pakan didalam rumen namun perlakuan yang terbaik adalah ransum yang mengandung silase sorgum samurai 2. Kata kunci : sorgum, kerbau, in vitro, in situ , radioisotop 32 P ABSTRACT In Vitro and In Sacco Examination of Buffalo Feed Rations Containing Sorghum Roughage. Sorghum is one of a potential fodder crops for buffalo feed in Indonesia. Samurai 1 and samurai 2 sorghum varieties are the result of mutation breeding by radiation from pahat sorghum varieties. This study was conducted to determine the potential of feed rations containing 50% samurai 2 and samurai 1 bagasse compared to feed rations containing 50% pahat sorghum roughage. Microbial growth rate of buffalo rumen ( in vitro ) and feed material degradation ( in sacco ) were determined. Completely randomized design with 6 treatments and 3 replications were applied in this experiment. The six treatment diets were: P1 (50% pahat sorghum straw + 50% concentrate), P2 (50% pahat sorghum straw silage + 50% concentrate), P3 (50% samurai 2 sorghum straw + 50% concentrate), P4 (50% samurai 2 sorghum straw silage + 50% concentrate), P5 (50% samurai 1 sorghum bagasse + 50% concentrate) and P6 (50% samurai 1 sorghum bagasse silage + 50% concentrate). Variables measured were pH, ammonia (NH 3 ), Total of Volatile Fatty Acid (TVFA), protein microbial synthesis (by 32 P radioisotope techniques), dry matter (DM) degradation, characteristics of DM degradation, Neutral Detergent Fiber (NDF) degradation and characteristics of NDF degradation. The results showed that P4 treatment produce the highest NH 3 concentrations, rumen bacteria growth rate and NDF degradation with 24,87 mg/100 ml; 8,11 mg/2 h/100 ml dan 31,96% respectively. TVFA concentration and pH were not significantly different between treatments. The conclusion of this study was the sixth treatment could support fermentation and digestibility in the rumen. The best treatment was buffalo feed based on samurai 2 sorghum silage. Key words : sorghum, buffalo, in vitro, in sacco, 32 P radioisotope