Effect of Increasing Dietary Crude Protein Concentration on Growth Performance and Serum Insulin-Like Growth Factor-I Concentration

ter digestibility, apparent digestible energy and apparent metabo-lizable energy are similar to the published values of Adeola and Bajjalieh (1997) and NRC (1998). Total nitrogen intake was similar (P > 0.10) between the corn varieties (Table 3). The amount of nitrogen digested (0.03 and 0.03 lb/d) and retained (0.01 and 0.01 lb/d) were similar (P > 0.10) between the corn rootworm protected and non-transgenic corns, respectively. Likewise, nitrogen digestibility (77.30 and 78.30%; P > 0.10) was similar between corns. The values for nitrogen digestibil-ity of the corn varieties used in this experiment are similar to the values published by Lawrence et al. (1995) and Adeola and Bajjalieh (1997). In conclusion, results of energy and nitrogen balance with growing pigs demonstrate that the potential Table 3. Energy and nitrogen balance.