Ans:

"Beef tenderloin" refers to the tenderloin of a cow.

"China's cattle carcass is roughly divided into twelve pieces, and modern slaughtering and processing enterprises divide beef into tenderloin (beef tenderloin), outer spine, eye meat, upper brain, breast meat, shoulder meat, milon, tendon meat, belly meat, etc."

dolarshop/shss1

china-ah/news/2005/06/02/59840.php

Upstairs there is a statement that "Beef tenderloin 'uses' the through loin of the cow "