A series of studies was conducted on the processing and utilization of oil palm frond (OPF) as a cattle feed. Chemical analysis revealed that OPF was composed of 70% fiber and 22% soluble carbohydrates on a dry matter basis. It was shown that OPF could be conserved as silage by determining the pH value and organic acid content in the silage. Urea addition at 1 to 2% (on a dry matter basis) at ensiling was found to be effective to prevent aerobic deterioration of OPF silage after opening of the silo by monitoring the change of temperature in the silage after exposure to the air. Nutritive value of OPF silage was found to be as high as that of rice straw based on voluntary intake and digestibility determined by the digestion trials using Kedah-Kelantan bulls. Feed intake, growth and carcass characteristics in Australian Commercial Cross fattening bulls, and feed intake and milk production in Sahiwal-Friesian lactating dairy cows were determined in the respective feeding trials and it was found that the optimal inclusion level of OPF in the diet ranged from 30 to 40% and was 30% for beef cattle and dairy cows, respectively. OPF has been found to be a suitable substitute for tropical grasses and has been successfully adopted by the ruminant producers in Malaysia.