One hundred 30-wk-old medium weight white Orlopp turkey breeder hens were equally divided into four treatment groups according to the level of available P in the diet (.15, .30, .50, and .70%, respectively). The P provided in the basal diet (.15% available, .35% total) was from cereal grains and soybean meal. No supplemental phosphate was added. During the 20-wk experiment, there were no differences in number of days required to come into lay and in subsequent egg production. Specific gravity, egg weight, number of shell pores, and body weight were similar under all treatments. The P levels of birds fed the four diets were 4.82, 4.93, 4.93, and 4.94 mg/100 mL, respectively, in serum and in femur were 15.8, 16.1, 16.8, and 16.4%, respectively. The P levels were slightly lower in birds fed the diet without added P. Excreta P levels (1.93, 2.49, 2.81, and 3.10%, respectively, in birds fed the four diets) were significantly (P less than .05) higher with each successive increase in dietary P. Hens fed diets containing .50 or .70% available P retained (46.9 and 54.8%, respectively) significantly more P than those fed diets containing .15 or .30% available P (28.1 and 33.8%, respectively). Fertility (76, 93, 90, and 89%, respectively) was significantly lower (P less than .05) from feeding the diet without added P. Hatchability rates of fertile eggs were similar for all treatments.
