Particles help

Hello,im new to blender,im making a project for the university and i a have a big problem with particles,I want to make the particles stop in a specific point,i have used a curve guide forcefield to control the particles direction,but they are constanty go beyond the point i want them to go,and secondly while in the renderview all seem normal,the cow is beeing disolved by faces,when render(with cycles) it goes a massive volume with particles,so big that makes the render extremly long,i have made to do a render with the particles being dissolved the way i want,but without the direction of curve guide force field,after i put the direction it stop working,i dont remember if i ve done anything other.
I m attaching the file so you can tell me your opinion.