Let down by its lack of pace
All in all, I didnt find it very entertaining, but this isnt to say parts of it were amusing, or could be if it just had more PACE.
The sprites were well handled, although you missed out on things like any sort of expression (when the cow was killed, when he saw the other cow... etc) which could have made it more watchable.
Pace and comical timing let this down heavily. The dialogue was comic and quite humourous, but some sentances took such a long time, with nothing else going on in the screen, that I lost interest half way through. To be sutible for the MTV generation, and to be a good short funny thing, it needs to keep the humour going, or maintain tension.
It does look very promising though, I liked the voice acting for the most part, and with your animation skills are good enough that you could make something really worth watching in future, dont be disheartened! (After all, this got on the front page)