Abstract: Fourteen male lambs of average weight of 14.46 kg were allotted randomly in two groups. One group (A) was kunnaned- a traditional Sudanese method used to control mating which envolves application of a double loop cord around the scrotum and the pendulous part of the ram's prepucial sheath, affecting mechanically normal penetration of the penis in the female genital tract, thus preventing conception. The other group (B) left entire. The two groups were fed on concentrate diet comprised of 15.24% crude protein and 10.48 Mj/kg metabolizable energy for 100 days. Feedlot performance and carcass characteristics were measured. Kunnand lambs had significantly (p<0.01) increased feed consumption than entire, but kunnan had no significant effect (p>0.05) on growth rate, feed conversion ratio and slaughter weight.