Marianne Yen's article on the highly profitable kosher slaughter business {news story, Nov. 2} reminds me of how tradition and dollars and cents can take precedence over compassion and common sense. Jewish and Moslem ritual slaughter has become inhumane because federal law mandates the shackling and hoisting of animals while they are still conscious. A one-ton steer hanging by one leg from a chain can suffer physical injury and psychological terror prior to having its throat severed.

Any animal that has any ''blemish'' prior to slaughter is not considered kosher. This means that most livestock subjected to ritual slaughter aren't actually kosher because shackling and hoisting often damage animals' legs. The hindquarters that are difficult to strip of blood vessels go into the general meat pool for public consumption.

While the Book of Isaiah advises that ''he who kills an ox is like he who kills a person,'' the fact remains that kosher slaughter, on the large scale that it is now practiced, is far from humane. There are humane alternatives that this billion-dollar industry should adopt, be it in the name of religious tradition or in the name of common-sense morality.

MICHAEL W. FOX Washington