Abstract
A 4×3 factorial experiment with four added dietary energy (fat) levels (0 (0.0), 24 (0.5), 48 (1.0), and 72 (1.5)kcal ME/kg (%fat)) and three protein levels (14.9, 15.5, and 16.1%) was conducted to determine the influence of dietary energy on performance, egg composition, egg solids, egg quality, and profits of Hy-line W-36 hens at different protein levels. The basal diets of the 16.1, 15.5, and 14.9% protein contained 2,784, 2,800, and 2,815kcal ME/kg, respectively. This experiment lasted 12 weeks. Hy-line W-36 hens (n=1440) in phase 3 (55 weeks of age) were randomly divided into 12 treatments (8 replicates of 15 birds per treatment). There was no interaction on performance, egg components, egg solids, and egg quality between protein and dietary energy. As protein level increased from 14.9 to 16.1%, percent yolk and yolk/albumen ratio linearly decreased and percent albumen linearly increased. Yolk color linearly increased as protein level decreased. Increasing dietary energy by the addition of poultry oil had no significant effect on performance, egg composition, egg solids, and egg quality. An ideal dietary energy level for optimal performance could not be determined for Hy-line W-36 hens during phase 3. Because feed ingredient prices and egg price vary, there can be no fixed ideal dietary energy level for optimal profits during phase 3.
