日粮磷水平对线性回归法测定磷真消化率的影响

Effect of Dietary Phosphorus Levels on the True Phosphorus Digestibility Estimated by the Linear Regression Method

本试验旨在研究日粮磷水平对线性回归法测定豆粕中磷真消化率的影响。选用48头平均体重为(36.0±0.1)kg生长公猪,采用2×3因子完全随机区组设计,随机分为6个处理,每个处理8个重复,每个重复1头猪。通过在半纯合日粮(低磷日粮,无玉米添加)和常规日粮(高磷日粮,含50.0%玉米)上添加3个水平豆粕(13.0%、26.0%和39.0%),研究日粮类型(低磷日粮和高磷日粮)对线性回归法测定豆粕中磷真消化率的影响。结果表明:随日粮豆粕水平增加,生长公猪的总磷摄入量、粪磷排泄量、可消化磷和存留磷量呈线性增加(P<0.01)。与低磷日粮相比,采食高磷日粮显著增加日粮总磷摄入量、粪磷排泄量、尿磷排泄量、可消化磷和存留磷(P<0.05)。通过使用线性回归法,生长猪采食高磷日粮测得豆粕中磷的真消化率为36.11%,显著低于采食低磷日粮测得结果 43.38%(P<0.05)。由此可见,由半纯合日粮(低磷日粮)测定得出的豆粕中磷的真消化率显著高于常规日粮(高磷日粮)的测定值,因此在使用半纯合日粮测得饲料原料中磷真消化率的数据用于日粮配置时应考虑上述因素。

The current study was conducted to investigate the effect of dietary phosphorus(P) levels on the true P digestibility(TPD)estimated by the regression method in soybean meal(SBM)for growing pigs.Forty-eight barrows with an average initial BW of(36.0±0.1)kg were allocated to 6diets in a 2×3factorial arrangement of 2diet types(low P diet without corn supplementation or high P diet supplemented with 50.0% corn)and 3SBM levels(13.0%,26.0% and 39.0%)by a randomized complete block design to study the effect of diet type(low P diet or high P diet)on the determination of TPD in SBM by the regression method.There were 8replicates in a treatment group with 1pig per replicate.The results showed that dietary P intake,fecal P output,digested P and retained P for growing pigs were increased linearly with increasing levels of SBM(P<0.01).Compared with the low P diet,pigs fed the high P diet increased dietary P intake,fecal P output,urinary P output,digested P and retained P(P<0.05).Using the regression method,the estimates of TPD in SBM for pigs fed the high P diet was 36.11%,which was lower than the determined value of 43.38%for pigs fed the low P diet(P<0.05).In conclusion,the estimated values of TPD in SBM were higher for pigs fed the semi-purified diet(low P diet)than that for pigs fed the practical diet(high P diet).Therefore,diet P levels should be consideredwhen using the determined values of TPD in feed ingredients derived from pigs fed semi-purified diet by the regression method for diet formulation.