<![CDATA[ABSTRAK Penelitian bertujuan mengkaji pengaruh penambahan pakan aditif dalam pakan ruminansia sebagai upaya meningkatkan aktivitas protease dan mengkaji pengaruhnya terhadap total protein cairan rumen pada lama inkubasi yang berbeda. Penambahan bahan aditif diharapkan dapat menjaga kondisi lingkungan mikro rumen tetap stabil dan dapat memberikan suasana yang optimal untuk kinerja bakteri rumen. Apabila kondisi lingkungan mikro rumen sesuai dan suasana rumen menjadi anaerob maka populasi bakteri rumen akan meningkat. Peningkatan populasi bakteri rumen akan berdampak pada meningkatnya aktivitas enzim yang dihasilkan. Penelitian bersifat eksperimental menggunakan metode in vitro. Perlakuan yang diuji yaitu P0 = Pakan basal (60% konsentrat : 40% hijauan); P1 = P0 + 0,5% isobutirat; P2 = P1 + 0,5% S. cerevisiae; P3 = P2 + 1% minyak kedelai. Penelitian menggunakan rancangan acak lengkap (one way classification), setiap perlakuan diulang sebanyak 5 kali sehingga terdapat 20 unit percobaan. Peubah yang diukur yaitu aktivitas protease menggunakan metode Walter dan kadar protein cairan rumen dalam pengamatan dinamika protein diukur menggunakan metode Bradford. Hasil analisis variansi menunjukan bahwa penambahan pakan aditif berpengaruh sangat nyata (p<0,01) terhadap aktivitas protease dalam cairan rumen dan hasil analisis variansi dinamika protein menunjukkan bahwa inkubasi 4 jam pada perlakuan P2 dan P3 menunjukkan perlakuan berpengaruh sangat nyata (p<0,01) terhadap kadar protein. Hasil akhir dari penelitian ini dapat disimpulkan bahwa penambahan kombinasi isobutirat, S. Cerevisiae, dan minyak kedelai pada substrat pakan merupakan perlakuan yang paling efektif dalam meningkatkan aktivitas protease dan mampu meningkatkan kadar protein cairan rumen pada jam ke 4 inkubasi secara in vitro.Kata Kunci: pakan aditif, protease, in vitro, proteinProtease Activities and Dynamics of Rument Liquid Proteins on In Vitro Feed Additives ABSTRACTThe aim of this study was to examine the effect of adding feed additives to ruminant feed as an effort to increase protease activity and to examine its effect on the total protein in rumen fluid at different incubation times. The addition of additives is expected to maintain a stable rumen microenvironment and can provide an optimal atmosphere for the performance of rumen bacteria. If the conditions of the rumen microenvironment are suitable and the rumen atmosphere becomes anaerobic, the population of rumen bacteria will increase. An increase in the population of rumen bacteria will have an impact on increasing the activity of the enzymes produced. This research is experimental using the in vitro method. The treatments tested were P0 = basal feed (60% concentrate: 40% forage); P1 = P0 + 0.5% isobutyrate; P2 = P1 + 0.5% S. cerevisiae; P3 = P2 + 1% soybean oil. This study used a completely randomized design (one way classification), each treatment was repeated 5 times so that there were 20 experimental units. The variables measured were protease activity using the Walter method and rumen fluid protein levels in the protein dynamics observations measured using the Bradford method. The results of the analysis of variance showed that the addition of feed additives had a very significant effect (p<0.01) on the protease activity in the rumen fluid and the results of the analysis of variance of protein dynamics showed that the 4-hour incubation in P2 and P3 treatments showed a very significant effect (p <0, 01) on protein content. The conclusion of this study is the addition of a combination of isobutyrate, S. cerevisiae, and soybean oil to the feed substrate is the most effective treatment in increasing protease activity and is able to increase rumen protein levels at the 4th hour of incubation in vitro.Keywords: feed additives, protease, in vitro, protein]]>
