How much weight can an adult Alaskan Malamute pull?

How much weight can an adult Alaskan Malamute pull and for how long, assuming the dog is in shape and well practiced, also, how much would you have to feed it each day under working conditions.

Check with the Alaskan Malamute Club Of America. They have weight pulls...Here is what i found...http://www.malamute.org.nz/Page.php?page=19

How much can s/he pull? About 8 times his or her own body weight when pulling on grass, snow or other natural surface. On pavement about 15 times his or her own body weight would be about average. Weight pulls are over very short distances, 20 to 40 feet.For longer distance sledding, a single Malamute should be able to easily manage 4 times his or her body weight on a sled for six to 8 hours per day. Amount of feed should be based on the dog's body condition, but Malamutes are generally "easy keepers", requiring considerably less food than one would expect of a dog that size. While working, I'd suggest a starting range of about 4 cups of high quality kibble per day, adjusted up or down as needed to maintain optimal body condition.