Cows aren't sapient,
Neither are these aliens.
cows aren't murdered for non-essential purposes.
They're killed as a source of food. Technicaly they
are killed for non-essential purposes as we could survive on other food sources instead.
These aliens were killed as a source of power to allow a ship and its crew to get back home alive. Otherwise they would have died. Just as essential (if not more so) than the cows.
And I doubt it's hundreds of cows for one person. Anyone who eats that much meat will probably be dead in less then a year.
Fine, then, hundreds of cows for roughly the same amount of people that was on the
Equinox.
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