Is it okay if my baby doesn't burp all the time after feedings?

I don't feed anymore and when i get up to feed him or my husband, we stop in the middle of the bottle and burp him and he does. But when he's done eating about another once (total of 4-5 oz) hes totally crashed wont wake up and just wont burp. He's not crabby or anything he just conks out. Just want to make sure it's okay just to put him back to bed. thank you!