Farm assurance means that someone is checking to make sure that the farmer is doing a good job taking care of their animals and crops. It's like the farmer is getting a report card for how well they are doing their farming.
The person who checks the farm looks at things like how clean the barns are and how healthy the animals look. They also check to make sure the farmer is using safe and responsible practices to grow their crops.
If the farm passes the assurance check, it means that the farmer is doing everything they should be doing to take care of their animals and crops. This is really important because it helps make sure that the food we eat is safe and healthy.