No. It is done by some but your child needs to vitamins and nutrients in the formula so much especially right now when they are growing and developing so rapidly.
In a month or month and a half he will be plenty ready to go to straight table food and milk in a bottle. I stared out the transition with 2 oz of regular whole milk, Vitamin D, and 6 oz. of formula. This lasts a week or so. If he has any problems with this stop the milk and go total formula until you figure out what is going on.
Then after the week you can go half formula and half whole Vitamin D milk. This is a tough stage since it really does taste different.
After they are used to the flavor and are drinking this very well, maybe another week to a week and a half you can go 6 oz. of regular milk mixed with 2 oz. Formula. This is the big one, they either take to it or they don't. If they don't like it this step may last weeks. They need to work through this stage though, you may have to go back to half and half though. Then start the next stage again.
It gets their tummy adjusted to milk by doing it this slow.
I cannot tel you how rancid and disgusting the pooh coming out of babies that go to too much milk in the mix right off. The ones that go cold turkey to milk have pooh and will gag even the most staunch diaper changer. I never changed one where the parent insisted we do the formula by just doing whole milk all of a sudden without having a trash can beside me to puke in. And diapers don't bother me as a general rule.
Their tummies will eventually adjust but why put them through the discomfort and nasty pooh.