Depending on how many shrimp you have, you may not need to feed nearly as much as you do.
See with ramshorns, you can use them as great markers of how much you feed.
Feed too much, you'll see explosions of them.
Feed too little, a die off.
Feed just right? They'll get a few to survive to adulthood.
In my fish tanks, I tend to overfeed as they are heavily planted so the fish have a harder time finding the food and the extra food basically becomes my macro dosing. lol. They have lots of snails. My shrimp tanks, I don't feed nearly as generously and they have far fewer snails.
Ramshorn especially seem to breed when they eat lots, they don't eat, they don't breed and it seems to be a pretty consistent rate at which they do vs food, so it's a great gauge on your feeding.