Yes, not a single day off if you have a herd of cows. On the other hand, as I said, I’m a person who had a single cow, and I got two months off a year. When a cow is no longer “fresh,” that cow stops milking for a minimum of two months. I guarantee you that every cow in your uncle’s herd got at least two months a year off from milking during the final months of that cow’s pregnancy.
I was a relief milker at multiple dairies, as well as doing all sorts of general dairy work for years. Personally, I never found the smell of a dairy unpleasant. Nothing like, for example, a chicken or turkey farm. Fowl farms smell foul.