Complex sentence: It is not uncommon for Zuds to kill over one million head of livestock in a single incident, with one record set in 1944 of almost 7 million head of livestock lost in a single winter.
Split into simpler sentences: It is not uncommon for "zuds" to kill over one million head of livestock in a single incident. A record was set in 1944 of almost 7 million head of livestock lost in a single winter.