I give my goats yam and sweet potatoes peel. They eat it very well. I think you are talking about Irish potatoes.
Moreover I live in Lagos state, Nigeria.
I need answers that can be used in Nigeria. Thanks.
I would still recommend a fecal to check lung worm, but dry cough is usually environmental, meaning dusty hay feed or some allergent.
Might start with an antihistamine once daily for a week a d see if there are any change. Make sure sweet potatoes peels are cleaned off before feeding.