There is no "humane" way of killing an animal/no "humane" slaughter

My reply to Lauren McGrath-Esler,
Even if you are allergic to many plant foods, there are still many plant foods that you can eat, and you can get all the nutrition that you need from plant foods. I recommend you to study this page: http://www.drmcdougall.com/med_allergic.html

You can also contact a vegan nutritionist.
“It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.” — Academy of Nutrition and Dietetics (formerly the American Dietetic Association)

You think that you can kill an animal “humanely”. You can’t. You can’t kill a healty animal "humanely", since the animal has a desire and interest to live her/his life and an interest of not being killed by humans. This is why painlessly killing a healthy animal is morally wrong: http://bloganders.blogspot.no/2013/07/why-painlessly-killing-animal-for-food.html

The slaughterhouses in Australia don’t kill the animals painlessly. There is no such slaughterhouse. Visit them and you will see. But even if there was, killing an healthy animal for the "pleasure"/convenience of animal foods would not be morally justified.
This is why it is morally wrong to kill animals for food:
1. It is wrong to inflict suffering and death on sentient beings (human or nonhuman) without any necessity.
2. Whatever necessity includes, it must, if it is to be meaningful, exclude the imposition of suffering and death for reasons of pleasure, amusement, or convenience.
3. Apart from life boat/desert island scenarios, there is no need to eat animal foods to be healthy.
4. Therefore, eating animal foods outside of extreme situations serves only pleasure, amusement, or convenience.
5. Therefore, it is morally wrong to inflict suffering and death on animals for food.

What do you say?