Effect of Different Combinations of Rice Straw, Cassava Powder, and Palm Kernel Cake on Intake and Digestibility by Ongole Crossbred Bulls

The present study investigated the effects of different combinations of cassava powder and palm kernel cake on intake and digestibility of Ongole Crossbred bulls fed a fixed amount of rice straw. Ongole bulls (n=24) were assigned to five dietary treatments (n=5 bulls/treatment for all treatments, except for T3 that had n=4 bulls) and allocated to individual pens in a completely randomized block design. The ration consisted of 5 g rice straw dry matter (DM)/kg liveweight.day with the different concentrate combinations offered ad libitum. Concentrates were prepared with different ratios of cassava powder and palm kernel cake respectively: 88:12 (T1), 75:25 (T2), 62:38 (T3), 50:50 (T4), and 38:62 (T5). Bulls were fed twice a day with drinking water available at all times. The experiment consisted of a 14-day adaptation period and a 7-day measurement period. Dry matter and organic matter (OM) intake were not different between treatments, although DM digestibility and OM digestibility were higher in T2 compared to T4 and T5 treatment diets (P<0.05). Bulls fed the T2 and T3 nutritional treatments had a higher digestible OM intake than bulls fed the other nutritional treatments (P<0.05). It is concluded that including cassava powder at 63 to 75% and PKC at 25 to 38% in a concentrate is the best ratio in a total mixed ration for fattening bulls when fed a small fixed amount of rice straw.