回归法测定生长猪内源磷排泄量及磷真消化率研究

为了确定多重线性回归法是否能应用于测定生长猪内源磷排泄量及菜粕和豆粕磷的真消化率,试验选用5头平均质量为(21.6±1.43)kg的健康大白×长白阉公猪为试验动物,采用5×5拉丁方设计,设5个磷水平(1.8,2.7,3.6,4.5和4.7 g/kg);日粮以豆粕、葡萄糖、玉米淀粉等为基础,以菜粕为待测植物性饲料,配制半纯合试验日粮,菜粕和豆粕为磷惟一来源。通过测定日粮和粪中的干物质(DM)、磷和氧化钛含量,计算出日粮、豆粕和菜粕磷的表观消化率。再应用多元线性回归分析,推导出生长猪内源磷的排泄量及豆粕和菜粕磷的真消化率。结果表明,以每kg干物质采食量(DMI)计,生长猪粪磷的排出量与日粮磷的摄入量呈线性关系(P<0.000 1);采食豆粕加菜粕日粮的生长猪内源磷的排泄量为(1.24±0.29)g/kg DMI,菜粕磷的真消化率为(46.46±11.33)%,豆粕磷的真消化率为(61.87±7.79)%;相对于表观消化率(-0.45%～35.15%),日粮磷真消化率(56.60%～59.03%)更稳定。说明多元线性回归法可以应用于同时测定猪内源磷排泄量和饲料磷的真消化率;在配制日粮时,磷表观消化率可加性差,而真消化率具有很好的可加性。

Endogenous outputs and true digestibility if phosphorus associated with rapeseed meal and soybean in growing pigs by multiple linear regression analysis technique

The aim of this study was to examine whether multiple regression analysis technique could be used to measure fecal endogenous outputs and true digestibility of phosphorus (P) in rapeseed meal and soybean meal for growing pigs.5 Yorkshire×Landrace barrows,with average initial body weight of (21.6±1.43) kg,were allocated to the five experimental diets according to a 5×5 Latin square design.The 5 experimental diets were formulated to contain 5 P level (1.8,2.7,3.6,4.5 and 4.7 g/kg),with the rapeseed meal and soybean meal as the mere P source.The apparent digestibilities of P in diets,soybean meal and rapeseed meal were measured.Then endogenous P output and true digestibilities of P in diets,soybean meal and rapeseed meal were determined by using multiple regression analysis technique,simultaneously.The P endogenous outputs were (1.24±0.29) g/kg DMI,true P digestibility of rapeseed meal was (46.46±11.33)%,and true P digestibility of soybean was (61.87±7.79)%.P outputs in feces increased linearly with the P inputs in diets (P<0.000 1).Multiple regression analysis technique was approved a novel method that could determine endogenous output and true digestibility of P for swine,simultaneously.True P digestibility rather than apparent digestibility,showed a perfect additivity associated with rapeseed meal and soybean meal when used in diet formulation.