[tonmoy]

Chicken production is already super energy efficient (and probably also the cruelest). Beef typically needs more land, at least if that land can be repurposed for growing crops (to turn into biofuel)

[Out_of_Characte]

You cannot repurpose almost all land that farm animals use to grow crop. This is marginal land where only grass grows, or hilly, rocky terrain where equipment is not effective.

[phire]

Yes, chicken does make me feel a little uneasy.

Beef and lamb are probably the least cruel, at least when they are fed grass outside (and where I live, they always are)

I understand that grain fed beef can be more cruel, depending on how long they are kept inside.