What do you feel weighs heavier: animal rights or religious rituals/customs?

In the Netherlands there is a discussion about (and an attempt at passing a law to) no longer slaughter animals (for consumption by Jews and/or Muslims) without anaesthetic. See here for kosjer slaughter.
The Party for the Animals is opposed to this method of ending the animal’s life, yet other political parties aren’t (as are the majority of members of both the Jewish and Islamic groups).
My gut feeling tells me that to anaesthetize the animal is the good thing to do (why inflict the animal with unneccesary pain).
One argument that the opposing parties voice, is that when it will be forbidden people who want to eat kashrut and/or halal meat will still do so (meaning that it will happen ‘underground’ or they will get it from abroad (meaning more German or Belgian animals will suffer hurtful deaths)).
What say you?