Answer:
Subsistence farmers are forced to migrate when they go in search of fodder for their animals.
Step-by-step explanation:
Subsistence farming is a kind of life where communities focus in survival, the kinds of crops that they plant are determined according to the kind of soil and whether they have besides what they will need during the following year, a big part of their food necessities are covered by the animal product, that's the reason why they have to take care of what their animals eat and have to provide them with the correct food.