Supplementation Effects of Ground Cassava and Cassava Leaves with Different Ratios on In Vitro Digestibility of Rice Straw Based-Diet

Abstract

The present study investigated the supplementation effects of ground cassava (GC) and cassava leaves (CL) with different ratios on digestibility of rice straw (RS) based-diet using in vitro technique. Two stages of in vitro ruminal digestibility were prepared and applied with different dietary treatments following: CON, consisted of 20% RS and 80% GC; T1, consisted of 20% RS, 70% GC, and 10% CL; T2, consisted of 20% RS, 60% GC, and 20% CL; T3, consisted of 20% RS, 50% GC and 30% CL; and T5, consisted of 20% RS, 40% GC, and 40% CL. Each dietary treatment was prepared in quadruplicate. All dietary treatments were incubated into rumen buffer along with three blanks for analysis of ruminal digestibility (in vitro first stage), and then continued into chloride acid solution with pepsin incubation for analysis of total digestibility (in vitro first and second stages). Previously, the rumen fluid was collected from two Bali steers that fed Pennisetum purpureum and commercial concentrate at 8:2 ratio. Both stages were conducted at 39C for 48 h, respectively. In the ruminal digestibility, an increasing ratio of CL was reported to decrease (P<0.05) dry matter digestibility (DMD) and organic matter digestibility (OMD) of diet. Digestibility of crude protein (CPD) in the rumen was highest (P<0.05) in dietary T3, followed by dietary T2, dietary T1, and then dietary T3 and T4, consecutively. Supported with results of ruminal digestibility, an increasing ratio of CL also decreased (P<0.05) DMD and OMD of diet in the total digestibility. Moreover, it also decreased (P<0.05) CPD of diet in the total digestibility. Therefore, the present study concluded that dietary treatment consisting of 70% GC and 10% CL with 20% RS presented the most optimum ratio resulting the highest digestibility through in vitro technique.