Whatever is available easily we can use. There is no objection to using electricity. But we should not be dependent upon it. Produce oil from castor seeds and stock the oil sufficiently. It can be used in so many ways—for burning, grease, cooking, and as a purgative to cure all diseases. And oxen can be used for driving carts and go preaching village to village. What is the question of killing them? Here in India our Lokanatha Maharaja has successfully organized such a program and it is a great success. He has traveled all over India and everywhere they distribute books, prasadam and perform kirtana, village to village. Each night they stop at a different village. We can introduce many millions of such carts all over the world.
If you are getting enough milk from the cows simply by pasturing them, then that is all right. But if you require more then you may have to feed them special grains. We want to do whatever is easy and save time for Krishna consciousness.
As far as you are able to adjust to a natural way of life, do it immediately. Our principle is that we are against nothing and for nothing. Only for Krishna. We want whatever is favorable for Krishna.