Performance of four strains of commercial layers with major changes in dietary energy

An experiment was conducted to determine how four strains of commercial lay ing hens would respond to an increase or decrease in dietary energy. Forty of each of Hy-Line Brown, Hy-Line W98, Hy-Line W36, and DeKalb White hens w ere fed each of three diets from 36 to 44 weeks of age. The energy contents of these diets were 2,519 (low), 2,798 (control) and 3,078 (high) kcal ME/ kg, The energy of low and high diets was 10% less and 10% more than the co ntrol diets, respectively, Hens fed the low energy diet consumed 8.5% more feed than did hens fed the control diet, and hens fed the high energy diet consumed 1.5% less feed than did hens fed the control diet, which indicated that the hens were more sensitive to lowering the energy than increasing e nergy in the diet. The Hy-Line W98 and the Hy-Line Brown were more sensitiv e to the change in energy than the Hy-Line W36 and DeKalb White. Egg produc tion (EP) was not affected by dietary energy level. The high energy diet (c ontaining 5.963% corn oil) significantly increased egg weight (EW). This di et may be beneficial for improving early EW.