Our farm has a bad genetic for not having eye guards. Maybe 1 in 5 won't have them or they are real small. Any ideas on how to prevent this?
All you can do is try to harvest them out and thin does until you get a situation where the best dominant bucks in the area have brow tines and can breed a higher percentage of available does and keep your fingers crossed. It's a very long term game plan.
Not much you can do about it aside from shooting them all for years to come and hope it somehow gets cleared out.
Only way to introduce eye guards is selectively take out the ones without. It's a tough job. How much land are you hunting?