Here are the thoughts of a Chinese Mahayana teacher regarding vegetarianism. According to Venerable Yin Shun, "Although it is not necessary for a Buddhist to be vegetarian, it is a good moral conduct in Chinese Buddhism and is something that should be promoted. The teaching of the Buddha says that becoming a vegetarian will cultivate one's loving kindness and compassion. By not harming the life of other living beings, not eating the meat of the other animals, one will reduce one's karma of killing and strengthen one's sympathy towards the sufferings of mankind. Mahayana Buddhism advocates the practice of vegetarianism, and says that to be a vegetarian has great merits in cultivating one's mind of loving kindness and compassion."
Ven. Yin Shun also said that: "To practise Buddhism and to be a vegetarian are not the same thing. Some people who become Buddhists do not learn much about the teachings but only know how to be vegetarians. This causes unhappiness among the members of the family. They feel that it is too troublesome to be a vegetarian. In fact one who is practising the teaching of the Buddha should, after becoming a Buddhist, first understand the teaching of the Buddha and behave according to the teaching in both the family and the society. Purifying one's conduct and mind, so that the members of the family feel that one has changed for the better should be the goal. If before becoming a Buddhist, one was greedy, had strong hatred and lacked a sense of responsibility and loving kindness; and after practising the Buddha's teaching, one becomes less greedy, less paranoid and shows more care to the others with a stronger sense of responsibility, then the members of the family would see the benefit of practising the Buddha's teaching. At that time, if one wants to be a vegetarian, the family members would not object to it. In fact, they may also be encouraged to have sympathy towards other living beings and follow one to be vegetarians. If one only knows [how] to be a vegetarian after becoming a Buddhist and does not learn about others, one will surely encounter obstacles and cause misunderstanding.