Although the javelin is out of fashion on the battlefield in the 14:th century, it still is in use in hunting. Livre the chasse shows javelins being carried while hunting several kinds of  game.
It is somewhat unclear if the javelin was used for actually killing the prey, or more of a ‘bleeder’, hurting game while on the chase so they will bleed out and tire faster, letting the hounds get to the prey and pull it down.

As the mort was usually done with a sword or dagger, I lean towards that theory.
The usual javelin in the manuscript dont have barbs. Barbs would be useful as it keeps the point in the game and the game will be considerably slowed from the shaft. Maybe the purpose was to bleed the game, as the heads are rather wide, and drop the javelin, leaving an open wound, and possibly leave the javelin to be picked up and used again. Blood-trails would also help the hounds to keep on the parfait (the right line, close on the game). We must remember that the chase of the hounds, not the actual kill was often the point of hunting, hunt-descriptions often relaying the thrill of the chasing hounds as the core of the hunt.

This is just speculations about the use of the spear… But since its my blog, I can speculate all I want.  You are also welcome to speculate in the comments, or on our facebookpage.

/Johan