<![CDATA[The objective of this experiment was to investigate the effect of substitution of U. lactuca to field grass on the in vitro digestibility of complete feed. Parameters measured were dry matter and organic matter digestibility, as well as total VFA and NH3 concentrations. This study was following a Completely Randomized Design (CRD) with 6 treatments and 4 replications, i.e: R0 = 60% field grass + 40% concentrate, R1 = 48% field grass + 40% concentrate + 12 % U. lactuca, R2 = 36% field grass + 40% concentrate + 24% U. lactuca, R3 = 24 % field grass + 40% concentrate + 36% U. lactuca, R4 = 12% field grass + 40% concentrate + 48 % U. lactuca, R5 = 60% U. lactuca + 40% concentrate. The results showed that treatments had significant effect (P<0.01) on DMD and OMD as well as the total VFA and NH3 concentrations. The result of statistical analysis showed that U. lactuca was able to completely replace grass in the complete feed because DMD and OMD were higher (67,99% and 70,04%) from control treatment (65,38% and 66,73%). While total VFA and NH3 concentration were significantly (P<0.01) higher in R3 (147.66 mM and 9.80 mM) compared to other treatments. It was concluded that the optimum level of the inclusion of U. lactuca in replacing field grass was 36%. ABSTRAK Penelitian dilakukan dengan tujuan untuk menguji pengaruh level U. lactuca sebagai pengganti rumput alam terhadap kecernaan in vitro pakan komplit. Parameter yang diukur adalah kecernaan bahan kering dan bahan organik serta konsentrasi VFA total dan ammonia (NH3). Penelitian ini disusun berdasarkan Rancangan Acak Lengkap (RAL) dengan 6 perlakuan dan 4 ulangan, yaitu: R0 = 60% rumput alam + 40% konsentrat, R1 = 48% rumput alam + 40% konsentrat + 12 % U. lactuca, R2 = 36% rumput alam + 40% konsentrat + 24% U. lactuca, R3 = 24 % rumput alam + 40% konsentrat + 36% U. lactuca, R4 = 12% rumput alam + 40% konsentrat + 48% U. lactuca, R5 = 60% U. lactuca + 40% konsentrat. Hasil penelitian menunjukkan bahwa perlakuan berpengaruh sangat nyata (P<0,01) terhadap KcBK dan KcBO serta konsentrasi VFA total dan NH3. Hasil analisis statistik menunjukkan bahwa U. lactuca dapat sepenuhnya menggantikan rumput alam dalam pakan komplit karena KcBK dan KcBO lebih tinggi (67,99% dan 70,04%) dari perlakuan kontrol (65,38% dan 66,73). Sedangkan konsentrasi VFA total dan NH3 meningkat mencapai puncaknya pada perlakuan R3 (147.66 mM dan 9.80 mM). Berdasarkan hasil penelitian ini, disimpulkan bahwa level kecernaan optimum U. lactuca menggantikan rumput alam adalah sebesar 36%.]]>
