This number is a scam, And just because a nice sounding woman answers in a voice mail does not make it legit, this number has been phoning me and claiming my bank has been compromised, I know my banks number and this is not one of them.
Horse slaughter is illegal in the US, there are no slaughter houses that handle horses in the US. The horses go to Canada or Mexico for slaughter. In Canada they are shot in the head, in Mexico, they are stabbed in the neck until their spinal cord is severed...and then they are slaughtered.
Most people in the US are not aware that horses are slaughtered there for human consumption in other countries. According to some of these polls, in New York, 64% of people polled believed that slaughtering horses for meat was illegal, while in Indiana, 91% believe that horse slaughter should be banned.[14] In Texas 89% of voters are unaware that horse slaughter was then going on in their own state.[15]
http://en.wikipedia.org/wiki/Horse_slaughter