What do you call a young male hog or swine?

The term used to describe a young male hog or swine is "young boar." A boar refers to an adult male hog, and so the distinction between a boar and a young boar is crucial in accurately identifying the age and gender of the animal.

The term "piglet" refers to a very young pig of either sex, typically under a few weeks old, and does not specify gender. "Sow" is the term used for a female pig that has given birth, which is not relevant when discussing young males. Thus, "young boar" is the most precise term for identifying a young male hog.