I'm ALAT certified and going for my LAT in May after I graduate. I included it in my application under awards and certificates. I'm not really sure if/how much it helped but I think it's definitely something to include. The way I look at it, it shows my professional interest in my expressed career interest (lab animal medicine) and also shows that I have some sort of backup plan if I don't get in the first time around. Taking the LAT would be another step in that general direction.