if its squirrels try buying a bag of dried blood from home depot or lowes, spread it around your sprouts and it will chase them away. only bad thing about using it, is when you get a big rain youll have to reapply it again ... not sure what to do if it was slugs

If slugs apply coffee grounds- but not used. Just buy the cheapest tin of fully caffeinated coffee you can get and apply liberally around the plant. The caffeine is neuro-toxic to them and other pest bugs. Can be used with the blood meal, which works wonders.

Another item that might help with both probs is soap shavings. Get a bar of ivory or whatever and make shavings around and in between the plants. Don't use anything antibacterial, though.

Squirrels like the sugar in the shoots, and once they discover your free salad bar, you need strong measures. I've tried a number of things over the years and the only thing that works consistently is a physical barrier. Go to Home Depot or equivalent and buy a roll of wire mesh with about a 1/2" square opening (it's near the chicken wire); they even make this product with a green vinyl coating. Cut pieces big enough to curl into cylinders about a foot high and fit them around any new shoots coming up; if the shoots are close together you can make a bigger cylinder and fit it around several of them, but don't make it so big a squirrel can jump inside. You can attach the top end to another culm with a twist of wire to stabilize it. Let the shoot grow up inside the cylinder. When the shoot is 1'-2' high it will have hardened off and you can remove the cylinder without fear of losing the shoot anymore.