Is there a better term for a male pig [literal sense--the animal] than "boar"?

There are three terms used for this purpose. Here's a description of all three from Wikipedia.

1. Boar or hog, male pig of breeding age.
2. Barrow, male pig castrated before puberty.
3. Stag, male pig castrated later in life (an older boar after castration).

If the species is called "hog" (AmE), the name for a full grown male hog is "boar", and "pig" for a young, weaned hog or any immature hog, and a "piglet" for a little pig, especially a suckling one.

http://www.merriam-webster.com/dictionary/pig

If the species is called "pig" (chiefly BE) or "swine", the name for a mature male pig is "hog", "shoat/shote" for a young, weaned pig or any immature pig, and "piglet" for a young, unweaned pig.

http://www.merriam-webster.com/dictionary/shoat

http://dictionary.reference.com/browse/piglet

It seems that the question is much more difficult than it may at first appear, as there are multiple names for male, female and even hermaphrodite pigs. These names take into account, among other things, age, weight, sexual maturity, “sexual degrees” (such as whether the males have been castrated, when there is only one testicle “showing,” or for hermaphroditic ones). For a good account of these multiple swine names and their meanings, see Rare Breed Pig Keeping, p. 54 (available online at http://www.gospbc.co.uk/wp-content/uploads/2013/07/RareBreedPigKeeping.pdf

Therefore there does not seem to be a single name for either a female or male pig, but several to choose from based on a wide variety of differences.