I am a breeder and just a few comments to say on this topic:
If you go through 20-30 horses in one battle your not playing tactfully enough. I realize this and I'm not a pvper
The fowl stage is there to keep from thousands of horses being bred which will slow down any server.And since you have the stage to wait this, SHOULD, cause you to think tactfully when you should or shouldn't use horses in battle.
Wurm is not an instant pvp game. (Sure you could take your sword and go attack people from the start but that's just stupid) You need to get your skills and abilities up to a decent level. This time is also a good time to start creating alliances and making friends. Yes you can make friends in Pvp. Its not just a Pve experience.
If you wanna pvp so fast than I suggest you play games like WoW. Their pretty decent and instant pvp is their main goal.
In summation fowls are there for a reason. Use it to your advantage. If need be make Alliances who have good Breeders and are willing to trade.
-1 Keep the fowl stage as it is