Is the word 'hog' a jargon in agriculture?

Answers are more or less correct except for referring to "pigs". A pig has not yet been weaned. When weaned, it becomes a shoat. When adult, it becomes a hog, either a sow or a boar. A swine is any member of the family Suidae, not just Sus scrofa. While those last are not "common" words, they are understood internationally and are standard and unambiguous.

In British English, 'swine' is plural. There is no such thing as 'a swine'. You are looking at swine if you are looking at several pigs. 'Swine' is also a rude word for somebody unpleasant.

I grew up in the 1950s with 'hog' as a less common form for 'male pig'. I see from other answers that 'hog' is a technical term for pigs of specific age etc. For me the female equivalent to 'hog' was 'sow'.

A "Hog" is a colloquial term for a Harley Davidson brand motorcycle, which is oddly appropriate since the motorcycle is also a sloppy mess.

It usually means a pig that is over 120 pounds in weight.

In the UK it can mean a sheep before its first shearing.

A swine is a more general term for a pig. 

Common words. VERY common words, too.

Not really, it's quite a common alternate word for "pig".  It's clearly understood by most non agriculturalists so that in my mind disqualifies it as jargon.

Update: What about swine?  It's just another synonym.  That happens in English.