Abstract:
This study was conducted on 228 typical South African feedlot steers, of which 114 steers
were fed 60 mg of zilpaterol HCl per steer per day for the final 30 days of the feedlot finishing
period and the other 114 steers were fed 120 mg of R-salbutamol per steer per day for the last
30 days of the feedlot finishing period. The animals were slaughtered at the same abattoir after
waiting the 3-day withdrawal period of zilpaterol HCl and R-salbutamol. The recorded growth
and feedlot parameters included starting weight, slaughter weight, average daily gain, live
weight gain and lean gain. The recorded carcass and meat characteristics parameters included
warm and cold carcass weights, carcass length, carcass fat thickness measured over the 13th
rib, carcass classification score, age code as well as fat code using the current South African
classification system, dressing percentage, and carcass compactness.
