questions on pressure cooking a cows foot for gelatin!

I was told gelatin from a cows foot is stronger and better then gelatin from pig neck bones, trotters etc. Is this true?

Anyone familiar with doing this? How many pounds of cow foot would i need for 3 cups of gelatin?

I assume i just cover with water as i would a stock? some aromatics as well.

I was planning on pressure cooking it for an hour- will this be enough time?

Once i am done with the bones can i reuse it? How much gelatin can i get from these guys?

any other uses for the bones?

thank you !