horse grazing pasture height
This is a tough question without knowing specific species in those pastures. Typically, as a broad generalization, we recommend going no shorter than 3" for grazing or mowing, and allowing pastures to rest until they are close to 8" in height. Then you can initiate grazing again. It sounds like you are trying to mow after grazing to even out the regrowth, which is perfect. If you can raise your mower bar to 3", that will put the grasses at a more even height and maturity, to promote more even regrowth for the next grazing event.
If you would like to get into any specifics regarding your individual farm, I would be happy to chat via phone or email. You can reach me at the information below.