According to Official Guinness Records,
The largest horn circumference on a steer measured 95.25 cm
(37.5 in) on 6 May 2003 and belong to Lurch, an African watusi
steer owned by Janice Wolf (USA) of Gassville, Arkansas, USA.
Sadly, Lurch died at 3 p.m. on 22 May 2010 of a cancer at the base
of one of the horns. The body has has been released to a local
taxidermist, who will produce a full-sized taxidermy of the
steer.
For a complete list of 2003 records, please visit 2003 Guinness Records in United States.