JAPANESE cows now have their personal paging systems... call, and they come -- more eagerly if its piano music that has distinct and individual notes. With cowherds becoming unaffordable in Japan, researchers considered the feasibility of an individual musical call that would be transmitted to the cow via tiny pagers fastened to its neck. It takes about two weeks to train the cows to respond to their individual musical notes. Relaying the music over loudspeakers is another technique being tried out on some Japanese farms.