EVALUATION OF SWINE DIET FORMULATION BASED ON AMINO-ACID DIGESTIBILITY ESTIMATES

Three experiments were carried out to test the hypothesis that formula tion of diets using true amino acid digestibility (TAAD) values for va rious alternative ingredients (AI) will result in similar performance to that achieved with a corn-soybean meal based diet. The TAAD values were obtained by swine ileal (I) and precision-fed (PF) rooster method s. A control corn-soy (C) diet provided the basal amino acid compositi on for use in the formulation of the AI diets. Additional diets with h igher amino acid levels were prepared using ileal (ID) and precision-f ed (DPF) digestibility data in formulation. Average daily gain (ADG) a nd feed intake (ADFI) were significantly higher (P less than or equal to.01) when pigs were fed the C diet than when fed either the I or PF diets. Feeding diets ID and DPF resulted in higher (P less than or equ al to.01) ADG and ADFI than diet I and PF respectively. Pair feeding t he C and AI diets produced same performance indicating that another fa ctor may be related with intake of diets. It was concluded that formul ation of diets using AI substituting soybean meal to levels of digesti ble amino acids equal to soybean meal-based diets may not give the sam e performance.