线性回归法测定生长猪内源磷排泄量及鱼粉磷真消化率

Determination of Endogenous Phosphorus Outputs and True Digestibility of Phosphorus in Fish Meal of Growing Pigs by Linear Regression Analysis Technique

本研究采用线性回归法测定生长猪内源磷排泄量及鱼粉磷的真消化率。选用5头健康大白×长白阉公猪为试验动物,平均体重为(27.17±0.28)kg。采用5×5拉丁方设计,设5个磷水平(0.08%、0.12%、0.17%、0.21%和0.25%),日粮以葡萄糖和玉米淀粉等为基础原料,鱼粉为磷唯一来源。日粮中添加0.1%TiO_2作为外源指示剂。试验分5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=0.292 7x-0.052 8,R^2=0.99,P<0.01),回归法测得生长猪内源磷的排泄量为0.798 5 g/kg,鱼粉磷的真消化率为71.12%。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鱼粉磷真消化率。

Regression analysis technique was used to measure endogenous outputs of the fecal phosphorus （P） and true digestibility of P in fish meal of growing pigs. Five Yorkshire × Landrace barrows with average initial body weight of （27.17±0.28） kg, were fed in the metabolic cage. According to a 5 × 5 Latin square design, the five diets with fish meal-corn starchglucose based experimental diet with five P levels （0.08%, 0.12%, 0.17%, 0.21% and 0.25%） were formulated, in which the fish meal was the only P source. 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. 292 7x - 0. 052 8, R^2 = 0.99, P〈0.01）, and the endogenous P outputs was 0. 798 5 g/kg and true digestibility of P in fish meal was 71.12% with regression analysis technique. There was no significant 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 analysis technique was valid for estimating diets endogenous P outputs and true digestibility of P in fish meal of pigs.