I have gone to field days and read articles / books on high stock density grazing. I am in E Texas, run 300 cows, calve end of Feb for 90 days. I run 2-300 yearlings as well. I practice rotational grazing now. Most pastures are 25 acres. I use electric fencing for 3 days grazing. I was to start high stock density grazing last spring when the grass got ahead, but the drought hit and never was able to get out of crisis mode. All I can say is that we survived and are still in business, but have a hole to try and get out of. The one thing that has been the most helpful to me on reducing hay cost is using stockpiled standing hay. I fertilize coastal in August for 2 months growth before frost, then graze dry pregnant cows using electric fence. I can usually make it to about Jan 1 on most years before needing hay. I can feed the cows hay from Jan until they calve. As they calve, they are moved back onto pasture of ryegrass / clover and some annual winter pasture. I really enjoy reading what others are doing and have tried different ideas. The other thing I have done that has really helped is to plant winter annual on leased land and move weaned calves off the main ranch in the fall, so that the cows have more acres (decreasing stock density) during the winter / early spring. This works for me because the lease cost is very low. I hope to start high stock density grazing this spring and that we will not have another severe drought.