to what does old major point to show that there are opportunities for the animals to run the farm on their own?

Old Major points out that the fields are fertile, the climate is good, and that the land would afford food in abundance. He also points out that there is enough land for thousands of animals to live on.

Old Major, said that the soil is fertile, the climate is good, also the land is capable of affording food in abundance to a great number of animals than now inhabit it.