We use the syringe pumps that are meant for IV medications to give feeds sometimes, just while we're not sure how well the babe is going to tolerate it. We can set them to any rate. General rule of thumb around here is that, if you're giving a new formula or have never fed a baby through an NG before, we usually set the pump to run in the feed over half an hour. So in that photo, he was getting 30ml and the pump was set for 60ml/hr, which gave it to him in 1/2hr.

If you're not sure your babes will tolerate formula or don't want to give it too fast, one way of doing it is to pull out the stopper in the syringe, attach the now-empty syringe to the tube and then pour in the formula. However high you hold the syringe determines how fast the feed will go in, and if you hold it fairly low (close to "nose level") it'll stop running in if their belly is full. You can lower it to slow the feed if they're crying, too. It's also a great way to get out nasty gas bubbles; just attach the empty syringe, hold it up and give a little push on the belly. That way any extra tummy contents flow into the syringe, not all over you!

Too much information? =)