Abstract
The influence of sex of broilers and dietary phosphorus (P) level on energy utilization and apparent ileal digestibility of N, P and phytate-P were investigated. The AMEN was determined using 3- and 6-week old broilers, while the apparent ileal digestibility were determined only with 6-week old birds. Sex of broilers had no effect on the AMEN values determined during week 3. During week 6, the AMEN values for male broilers were higher (P < 0.01) than those for the females. An interaction (P < 0.05) between sex and dietary P level was also observed. AMEN values determined with male broilers were lower in the adequate-P diet compared to those in the low-P diet, whereas no effect of P level was observed in females. Female broilers tended (P < 0.10) to have a higher ileal N digestibility than the males, but a significant (P < 0.01) sex × P level interaction was observed. Males receiving the adequate-P diet had a lower N digestibility than those receiving the low-P diet, whereas the opposite was true in the females. Ileal phytate P degradation in males was higher than in females (0.282 vs. 0.234), but the differences were not significant. Increasing dietary P level increased ileal P digestibility in both the males and females, but the improvements were greater in the females, as indicated by a significant sex × P level interaction.