You may have some herds that are not yet grazing. These herds will not appear on the map. You can find them in the Herds tab. To move a herd into a pasture, click on the Herds tab and click the "Move into pasture" button:
In the next screen, select the pasture and date the animals started grazing the pasture.
If you have the Grazing Chart in your plan, you can also add historical moves and planned moves for these herds by clicking on "Grazing Chart" at the top and moving your mouse over "Add Herd Move".