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.
Effects of glycine and glutamine supplementation to reduced crude protein diets on growth performance and carcass characteristics of male broilers during a 41-day production period
