A lot of that has to do with how long it was exposed to ambient tempreature after being killed. If it was exposed to warm temps for several hours before freezing, it won't last as long as if it were not exposed very long. Decomp starts right away. If you give it a head start, it just takes off again as soon as it thaws out. If processed quickly, it should last a couple of days. Sniff it, you'll know bad meat when you get a whiff of it.