Allot of times breastfed babies don't burp. It's much easier on their tummies and they aren't getting air that is remaining in the bottle. My son rarely did. If he's fussing it may be gass in the lower tract. Try bicycling his legs to break up and gas below.
You could try burping him during feedings. Like after every ounce or so that he drinks instead of just at the end. Sometimes that helps. If that doesn't work then theres gripe water you can get from the store that's completely safe for babies. It Also helps with any tummy aches.