Here's an awesome thing about oxen:
They make MOAR of themselves.
They are also made of meat.
When they're too old to pull the plow, they've likely gotten stringy and nasty.
29th Street isn't a bad neighborhood, it's an adventure!
Although it is outside the purview of this organization to offer personal advice, we can say -- without assuming any liability -- that previous experience indicates (and recent market studies corroborate) that given the present condition of the marketplace, continuing with your present course of action is likely to result in substantial increases in corpse production.