It's a fact of life, survival of the fittest. The strong feeds on the weak, the weak dies in agony and experiences excruciating pain in the death process. 

If we had not fed on meat, what will we survive on? Vegetables?

If you were bathing in the toilet and you saw an ant struggling in the water, would you bend down and rescue it, or just let it drown?

If a fly keeps on bugging you during your meals, would you attempt to kill it, or brush it away from your sight?

There's no doubt that we have the power to take control of all kinds of life on this planet. But think again, would you rather save lives or take them away?