二元线性回归法测定生长猪内源磷排泄量及麦麸和豆粕磷的真消化率

本研究采用二元线性回归法测定生长猪内源磷排泄量及麦麸和豆粕磷的真消化率.选用6头健康大白×长白阉公猪为试验动物,平均体重为(34.42±0.64)kg.采用6×6拉丁方设计,设6个总磷水平(0.12%、0.25%、0.28%、0.35%、0.47%和0.54%),日粮以豆粕、葡萄糖、玉米淀粉等为基础原料,麦麸和豆粕为磷来源.日粮中添加0.1%TiO2作为外源指示剂.试验分6个试验期,每期6 d,4 d适应期,2 d收粪期.结果表明,生长猪粪磷的排出量与日粮磷的摄入量呈线性关系(y=0.515 7x-0.0133,R2=0.97,P<0.01),回归法测得生长猪内源磷的排泄量为0.933 0g/kg,麦麸和豆粕磷的真消化率分别为48.07%和47.50%.分析粪磷来源发现,内源磷排泄量基本不变(P>0.05),而粪磷随日粮磷含量的增加而极显著增加(P<0.01).由结果可知,线性回归法可用于测定猪内源磷排泄量及麦麸和豆粕磷的真消化率.

Determination of Endogenous Phosphorus Outputs and True Digestibility of Phosphorus in Wheat Bran and Soybean Meal of Growing Pigs by Binary Linear Regression Technique

Binary linear regression analysis technique was used to measure the endogenous phosphorus (P) outputs and true di-gestibility of P in wheat bran and soybean meal of growing pigs.Six Yorkshire×Landrace barrows with average initial body weight of (34.42±0.64) kg, were fed in the metabolic cage.According to a 6×6 Latin square design, the six diets with soybean meal-glucose-corn starch based experimental diet with six P levels (0.12%, 0.25%, 0.28%, 0.35%, 0.47% and 0.54%) were formulated, in which the wheat bran and soybean meal were the P sources.TiO2(0.1%) was included in the diets as exogenous indicator.Each experimental period lasted for 6 d with 4 d of adaptation and 2 d of fecal collection.The results showed that, there existed increasing linear relationships between endogenous P outputs and dietary P inputs (y= 0.5157x-0.0133, R2=0.97, P<0.01), and the endogenous P outputs was 0.933 0 g/kg and true digestibility of P in wheat bran and soybean meal were 48.07% and 47.50% with regression analysis technique, respectively.There was no sig-nificant differences (P>0.05) in endogenous P outputs by analysis of fecal P sources; while, there was significant increasing linear relationship (P<0.01) between fecal P and dietary inputs of P.In conclusion, it was implicated that regression analy-sis technique was valid for estimating diets endogenous P outputs and true digestibility of P in wheat bran and soybean meal of growing pigs.