Boar or brawn, the sire; sow, the dam; sucklings, the new-born pigs. A castrated boar-pig is called a hog or shot. Young pigs for the butcher are called porkers.
A sow-pig after her first litter becomes a brood-sow, and her whole stock of pigs cast at a birth is called a litter or farrow of pigs.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894