Dietary inorganic phosphorus levels for weanling swine
1990
Mori, T. (National Inst. of Animal Industry, Kukizaki, Ibaraki (Japan)) | Takada, R.
Two experiments were conducted, involving 49 weanling pigs to determine the dietary inorganic (available) phosphorus requirement from 8 to 25 kg body weight. All diets were formulated with corn starch and corn gluten meal (60%cp); dicalcium phosphate and limestone were used as inorganic mineral sources to adjust the total dietary phosphorus(p) concentration. In the first experiment pigs were allocated to five dietary P levels ranging from 0.10 to 0.30% in 0.05% increments, while dietary Ca were maintained at 1.2-1.3 times of P levels. In the second experiment, pigs were allocated to four dietary P levels ranging from 0.25 to 0.40% in 0.05% increments, while dietary Ca were maintained at 1.2-1.3 times of P levels. Blood and bone samples were collected at the end of each experiment and the bone weights and the ash contents were determined. Two metabolism trials were also conducted to determine the effects of dietary phosphorus level upon phosphorus balance in weanling pig. In the first experiment, increasing the dietary P levels from 0.10 to 0.30% resulted in increased daily gain, feed intake and feed efficiency. In the second experiment, dietary P levels influence pig daily gain, feed intake and feed efficiency showing the highest values at the 0.30% dietary P level. Serum P reached maximum at dietary P levels of 0.30%. The weight and mineralization of the femur bone showed maximum at 0.40% dietary P and bone ash percentage 0.35% dietary P. In metabolism trials, P retention increased until dietary P levels of 0.25% in the first trial and 0.30% in the second trial. Urinary P excretion was not increased until dietary P level of 0.25%, but above 0.30% it increased dramatically as dietary P increased
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