His intentions are two-fold. He wants to embue the animals with a feeling of patriotism to make them want to sacrifice all for the farm; he also channels their collective attention in the direction he wants it to go as to allow no place for individual thinking and reflection.
These tactics are a combination of 'bread and circuses' (for diversion and gratification) and outright brainwashing (for conformity and obedience).
Well Napolean holds these ceramonies to show his power and dominence on the farm. These demonstratins trick the animals into thinking he is a sufficient leader. This is in a sense another form of propoganda in order to sway the views of the animals and prevent a revolution.