What breed was the white husky bred for looking after sheep in the snow?

The breed you are referring to is likely the Alaskan Malamute. While not a husky in the strictest sense, Alaskan Malamutes were developed for their strength and endurance to haul heavy sleds and assist in hunting, particularly in snowy environments. They are known for their thick, white and gray fur, which helps them cope with cold conditions, and they have a strong herding instinct, making them suitable for looking after sheep in snowy terrains.