The effects of carbadox on the performance and carcass characteristics of early-weaned pigs given high- and low-protein diets

Abstract

ABSTRACTThirty-six male pigs weaned at 28 days of age were used to study the effects of methyl-3-(2- quinoxalinylmethylene) carbazate-N1, N4-dioxide (carbadox) in high- and low-protein diets on the performance of pigs growing between 7 and 32 kg live weight, and on carcass characteristics at the latter weight.The inclusion of carbadox (55 mg/kg) in a high-protein diet containing 195 g crude protein per kg and 10·2 g lysine per kg had no effect on performance or on carcass characteristics. Pigs offered the high-protein diets grew more rapidly, had a lower food conversion ratio and were leaner at 32 kg live weight than those offered a lowprotein diet containing 146g crude protein per kg and 6·0 g lysine per kg. Supplementation of the low-protein diet with lysine (4·2 g/kg) had no effect on performance or carcass characteristics but the inclusion of carbadox in the low-protein diet increased growth performance and reduced carcass backfat measurements at 32 kg. However, the performance was inferior, and the backfat thickness greater, compared with the high-protein diets. On the other hand, supplementation of the low-protein diet with lysine plus carbadox raised growth performance and reduced carcass backfat measurements to the levels exhibited on the high protein diets.