Live Tackling in Practice

As a team we are having trouble tackling this year a lot more then most years. The question that I have for you guys is how often do you live tackle (ie to the ground) during practice? Other then the first few days of practice during camp or 2 a days we don't ever tackle to the ground. We do what we call "thud" practice and I am worried that this is our problem why our guys don't "finish" the tackles.

We do tackle the sled, work on form and other drills all year long but it just doesn't seem to help, especially this year.

So I was wondering how many of you guys actually did live "team" periods, or at least live defensive team periods.

Thanks for any responses.