In my last field work in Bama in Burkina Faso, we had a very long and interesting discussion with the livestock union, bringing together the association for dairy farmer, for fattening farmer and butchers.
We had a lengthy discussion with them about their cattle keeping systems and their challenges. No word was lost about goats and sheep. So we did as always, we just asked.
However, a cattle keeper will always keep sheep. They have similar grazing pattern than cattle and therefore can be kept together. Often livestock keeper have a breeding strategy, and manage their herd accordingly. So they do not want to sell off cattle when they have a urgent money need. That's why they keep sheep : in order to have something small to sell off to pay for something unexpected, such as a family member who gets sick and one need money for health care. It is a risk management strategy that allows them to not touch their herd. "Sheep is the panty of the herd" they told us. The last thing you can strip before you have to touch you herd.