I learn this actually from Master Chin Kung VCD talks. All beings have the seeds of Buddha nature. It means that all can become Buddhas. Thus, we should treat them all equally. That's so simple to talk, but really hard to put into action. The way Mahayana achieve this is to enlarge their heart tolerance. Once, your heart can tolerate every being in every situation, you are using the heart of a Buddha. I remembered that Master Chin Kung had ever said that the Buddhas use "equal heart" and Bodhisattvas use "Six Paramitas heart" in their practice in saving all beings.
The closest beings to us (except human) that we see every day is "the animals". Based on the teachings of the Buddha, we should try to save all beings with true sincerity. There are many reasons why this should be done, concerning "liberating animals". I suggest that you go through search for videos in Youtube or Buddhist site about this. But truly, we should understand that all animals are afraid of death, not only human.
According to Buddhism, "Liberating animals" can increase life span, improving health, freeing stress, increasing fortune and wisdom, creating good affinity with them, etc. I used to go "liberating animals" with my friends. Actually, whether you are a vegetarian Buddhist or not a vegetarian Buddhist, you should still do this. This is very important, especially in Mahayana Buddhism where "saving beings" is always stressed.
There are few steps to follow when you want to do "animal liberation".
- Put priority for those which are going to be killed/bought food first, like "crabs", "prawns", etc. Cause if you don't buy them and free them, they will be bought and killed. Life is precious and all beings are afraid of death.
- Some animals are kept as pets. They also don't want to be kept in a small place, even though you give a very large cage. Do you want to live a luxurious prison, even if you are given food every day? Use your wisdom to choose whether to buy these pets like rabbits and other wild animals that kept as pet. If it lives in the wild jungle, you should return it to the jungle. But still the same word, consider your action before you buy and do liberation.
- Be wise in buying animals. Some people sell these animals, and they know that you want to buy at a certain date (if you do this as a routine activity). Don't always buy at the same place. They will think that selling animals is a good business and thus keep on buying and capturing lives for sale. Actually, it's not enough to explicitly express what I mean. I still hope that you are able to watch the videos (you need to do it at search engine).
- Buddhists usually have "pre-liberation chanting". This chanting is for protecting the animals which we are going to liberate. Giving them "the three refuges". Another reason is to create good affinities with them. There's a saying: "Bodhisattvas, before becoming Buddha, should first create good affinities with all beings. And from this saying, we know that we should even create good affinities with people around us. And be tolerate.
- Then, since we have done a good deed for liberating animals, we should "transfer the merit" towards all beings. This is like sharing joy and happiness with all sentient beings. The first transference is towards all beings and next to our karmic creditors, then we can also tranfer the merit to our family member. We can actually just use the "Merit Transfering Verse" that has been passed down since long ago.
- create good karmic affinity with them,
- develop the compassion in our hearts and
- let the animal have affinity with Buddha, Dharma, Sangha before their death, and thus letting them to be born in a better realm.