The effects of enzyme and inorganic phosphorus supplements in wheat- and rye-based diets on laying hen performance, energy, and phosphorus availability
1998
Pan, C.F. | Igbasan, F.A. | Guenter, W. | Marquardt, R.R.
A total of 640 22-wk-old pullets (Shaver SX 288) housed four birds per cage in 40 experimental units (four cages per unit), were randomly assigned eight experimental diets in a 2 x 2 x 2 factorial arrangement. The treatments consisting of two grain sources (wheat and rye) two levels each of crude enzyme preparation (0 and 0.1% Roxazyme G), and added inorganic phosphorus (0 and 0.105%) were fed for five 4-wk periods. At 42 wk of age, 40 individually caged layers were fed the experimental diets with 0.3% chromic oxide (5 individual birds per treatment) to determine AME(n) and available P. Plasma P and Ca were also determined. Egg production, feed intake (FI), egg weight, feed efficiency (FE), and specific gravity of eggs were significantly (P less than or equal to 0.05) affected by the experimental periods. Hens fed wheat-based diets had higher (P less than or equal to 0.05) tibia ash (54.3 vs 52.5%), excreta dry matter (22.0 vs 17.7%), and eggshells with greater than or equal to 1.080 specific gravity (93.5 vs 89.9%) than birds fed rye. Enzyme supplementation significantly improved AME(n) (P less than or equal to 0.01) and FE by 6.2 and 3%, respectively. Egg production increased numerically from 87.6 to 90.1%. Inorganic P supplementation significantly increased egg production (P less than or equal to 0.01), FI, FE, and AME(n) (P less than or equal to 0.05) by 4.4, 2, 3, and 2.8%, respectively, but significantly (P less than or equal to 0.05) decreased the proportion of eggs having a specific gravity greater than or equal to 1.080 from 92.8 to 90.6%. The enzyme and inorganic P supplementation had no effect on tibia ash content and total plasma Ca and P. Rye can be used in layer rations yielding satisfactory performance when fed with a fungal crude enzyme preparation high in pentosanase/xylanase activity.
显示更多 [+] 显示较少 [-]