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The human population is increasing from year to year. Meanwhile, urbanization is increasing and incomes are rising in many parts of the world, particularly in some developing countries, resulting in increased per capita demand for meat, milk and eggs (Delgado et al 1999). The demand for these food products is increasing at a faster rate than the growth in cereal production, and is consequently putting unprecedented pressure on the traditional feed resources used in livestock production (Delgado et al 1999). The combination of high demand, more people and less space is rapidly leading to a global transformation of the livestock sector, from one that mobilizes surplus and waste resources to one that actively seeks new feed resources for the production of animal food products.
Among the potentially valuable unconventional feeds, cassava leaves have attracted the attention of many researchers because they are high in protein (170 to 400g/kg of DM) (Ravindran 1993) and are a good source of minerals, particularly Ca, Mg, Fe, Mn and Zn (Ravindran and Ravindran 1988). Cassava leaves are also rich in ascorbic acid and vitamin A, and contain significant amounts of riboflavin.
One plant that has not been given much consideration yet is oil palm (Elaeis guineensis). It grows widely in the humid tropics, tolerates poor soil and has a high yield potential (Ocampo et al 1990, 1994; Gohl 1992). The potential use of crude palm oil and its by-products as a cereal grain replacement in livestock feed is now becoming of importance for several tropical countries (Hutagalung et al 1981; Devendra et al 1981; Ocampo 1990, 1992; Preston and Murguitio 1992).
The following experiments were carried out in order to increase the knowledge of the nutritional potential of palm oil with emphasis on its role as a high energy supplement in pig diets based on ensiled cassava leaves:
The effect of graded levels of palm oil on digestibility and N balance
The effect of the age of cassava leaves and crude or refned palm oil on digestibility and N balance
The effect of graded levels of palm oil on performance traits in pig diets based on high levels of ensiled cassava leaves