A female pig that hasn't yet farrowed (had a litter of piglets) is called a gilt, once she has had a litter she is then called a sow, I was assistant breeding herd manager of a pig farm a while back.
The answer for the DTGK Xword is Gilt.
Incinently, about 30 years ago I made my 1st trip to Malta and asked what sort of sheep the farmers they were running. [Being a farmer , I like to know these things.] They were smallish with multi coloured, shaggy coats. I was informed that they were "Shoats" --- A cross of a goat and a sheep! mmmmm...think my leg was being slightly tugged!
Jim