The palm kernel is the edible seed of the oil palm fruit. The fruit yields two distinct oils: palm oil derived from the outer parts of the fruit, and palm kernel oil derived from the kernel.[1]
The pulp left after oil is rendered from the kernel is formed into "palm kernel cake", used either as high-protein feed for dairy cattle or burned in boilers to generate electricity for palm oil mills and surrounding villages.
Palm kernel cake is a high-fibre, medium-grade protein feed best suited to ruminants.[3][4] Among other similar fodders, palm kernel cake is ranked a little higher than copra cake and cocoa pod husk,[5] but lower than fish meal and groundnut cake, especially in its protein value.
Composed of 16% fiber, palm kernel cake also has a high phosphorus-to-calcium ratio and contains such essential elements as magnesium, iron, and zinc.[6] The typical ration formulated for the feeding of dairy cattle consists of palm kernel cake (50%), molasses (5%), grass/hay (42%), limestone (1.5%), mineral premix (1%), and salt (0.5%), with trace element/vitamin premix.[7]
Palm kernel shells (PKS), a byproduct of palm kernel oil production, can be used for biofuel (for example, in the form of pellets).[8]