To what does Old Major point to show that there are opportunities for the animals to run the farm on their own?
He points to how fertile the soil is and how nice the climate is. He says that the farm could support so many more animals than it does now. He says that this proves that they would be able to live better lives if they controlled the farm.
Old Major says this when he gives his speech to the animals in Chapter 1. He argues that the farm could support twenty cows and a dozen horses and a bunch of other animals in comfort. The reason it doesn't is because the humans steal all the food the animals work hard to create.
If the animals ran the farm, they'd have all that food for themselves and they would live better than they do now.
In the book on page 8 Old Major is speaking to the animals about England. He tells them that no animal in England has every felt happy. He equates their lives to misery and slavery. He reminds them that the farm soil is fertile, the climate is good, and could produce food in abundance. He continues with his speech by telling the animals that man has caused all their problems.
During Old Major's speech he tells the animals that all of the bad things in life came from tyrant humans. He explains to them that he knows they could become rich overnight. He wants them to know that they need to get rid of mankind in their lives and work for themselves; in this manner what they work for will be their own. He wants the animals to revolt against the humans and calls for their unity.