Determination Of The Endogenous Calcium And Phosphorus Losses And True Calcium And Phosphorus Digestibility Values Associated With Soybean Meal For Swine By Linear Regression Analysis Technique

Regression analysis technique was used to measure the fecal calcium (Ca) and phosphorus (P) endogenous outputs and true Ca and P digestibility values with soybean meal in studies with dry sows and WuZhiShan gilts.Experiment 1: Six Yorkshire X Landrace dry sows, average initial body weight 200kg and 5-7 parity, were fed in the metabolic cage(piglet bed). According to a 6X6 Latin square design, the six soybean-cornstarch-glucose based experimental diets containing six Ca level (0. 04%. 0. 09%, 0.13%, 0.17%, 0. 22%, 0. 26%) and P level (0. 09%, 0.18%, 0.27%, 0.35%, 0.44%, 0. 53%) were formulated, in which the soybean meal was the only Ca and P source. Chromic oxide (0.35%) was included in the diets as digestibility marker. Each experimental period lasted 8 d with 5-d adaptation and 3-d collection of the feces. The results showed that the Ca and P endogenous outputs were 1.19 g/kg±0.12g/kg DMI, 0.78 g/kg±0.17g/kg DMI in dry sows, and true Ca and P digestibility with soybean meal were 27%±5.0%, 44% ±4.5% determined with regression analysis technique.Experiment 2: Six WuZhiShan gilts, similar in litters, average initial body weight 16.8 kg±0.70kg, were fed in the metabolic cage. According to a 6×6 Latin square design, the six soybean-cornstarch-glucose based experimental diets containing six Ca level (0.04%, 0.09%, 0.13%, 0.17%, 0.22%, 0.26%) and P level (0.09%, 0.18%, 0.27%, 0.35%, 0.44%, 0.53%) were formulated, in which the soybean meal was the only Ca and P source. Chromic oxide (0.35%) was included in the diets as digestibility marker. Each experimental period lasted 8 d with 5-d adaptation and 3-d collection of the feces. The results showed that the true Ca and P digestibility with soybean meal were 29%±6.4 %, 35%±8.1 %, and Ca and P endogenous outputs were 0.50 g/kg±0.16 g/kg DMI 0.53 g/kg±0.18 g/kg DMI in the WuZhiShan gilts determined with regression analysis technique.