THE EFFECTS OF ENZYME AND INORGANIC PHOSPHORUS SUPPLEMENTS IN WHEAT-BASED AND RYE-BASED DIETS ON LAYING HEN PERFORMANCE, ENERGY, AND PHOSPHORUS AVAILABILITY

A total of 640 22-wk-old pullers (Shaver SX 288) housed four birds per cage in 40 experimental units (four cages per unit), were randomly as signed eight experimental diets in a 2 x 2 x 2 factorial arrangement. The treatments consisting of two grain sources (wheat and rye) two lev els each of crude enzyme preparation (0 and 0.1% Roxazymes(R) G), and added inorganic phosphorus (0 and 0.105%) were fed for five 4-wk perio ds. At 42 wk of age, 40 individually caged layers were fed the experim ental diets with 0.3% chromic oxide (5 individual birds per treatment) to determine AME(n) and available P. Plasma P and Ca were also determ ined. Egg production, feed intake (FI), egg weight, feed efficiency (F E), and specific gravity of eggs were significantly (P less than or eq ual to 0.05) affected by the experimental periods. Hens fed wheat-base d diets had higher (P less than or equal to 0.05) tibia ash (54.3 vs 5 2.5%), 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 tha n 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) d ecreased 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 supp lementation 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/x ylanase activity.