Which is better substitute of mothermilk ... Is it cow milk or formula milk ...

I gave both my kids fresh cow milk, goat milk and occasionally oat milk after they turn 14 months for supplement at school. At home, they still latch. To me, I prefer plant based milk but my kids prefer the cow milk that why I continue to give them. I am never into the FM as I study the ingredients list before it is not something I will put into my own mouth hence not to mention for my kids. Just my two cents worth. However, fresh cow/goat milk or plant based milk is only recommended to introduce to children after the age of 1 year old.