肉鸡饲粮钙磷比对豆粕中磷真消化率的影响

摘要

本试验旨在使用线性回归法和差量法研究肉鸡饲粮钙磷比对豆粕中磷真消化率的影响。选用576只15日龄罗氏肉鸡，根据3×3因子完全随机区组设计分为9个处理，每个处理8个重复，每个重复8只鸡。通过添加3个水平的豆粕(30.00%、43.00%和56.00%)，研究饲粮钙磷比(1.0、1.5和2.0)对豆粕中磷真消化率测定值的影响。试验期7 d。结果表明：肉鸡体增重、饲料转化效率、回肠食糜磷排泄量和可消化磷均随豆粕水平提高呈线性增加(P<0.01)，而干物质消化率和磷的表观消化率呈线性降低( P<0.01)。提高饲粮钙磷比可显著增加回肠食糜磷排泄量，从而降低可消化磷和磷的表观消化率( P<0.01)。使用线性回归法和差量法在钙磷比为2.0时测得豆粕中磷的真消化率分别为40.79%和39.84%，显著低于钙磷比在1.0(53.36%和55.59%)和1.5(56.81%和56.36%)时测得磷的真消化率(P<0.05)。由此可见，肉鸡饲粮钙磷比显著影响豆粕中磷真消化率的测定，但真消化率计算方法(线性回归法和差量法)对测定结果无显著影响。%This study was conducted to investigate the effect of dietary calcium-to-phosphorus ratio ( Ca∶P) on true phosphorus digestibility ( TPD) in soybean meal ( SBM) for broiler chickens by the regression method and the difference method. A total of 576 male Ross broilers at 15 days of age were used in a randomized complete block design with a 3 × 3 factorial arrangement of 9 diets. There were 8 replicates per treatment with 8 birds per replicate. To study the effect of dietary Ca∶P (1.0, 1.5 and 2.0) on the determination of TPD in SBM, our experiment supplemented 3 levels of SBM (30.00%, 43.00% and 56.00%). The experiment lasted for 7 days. The results showed that body weight gain, feed conversion efficiency, P output in ileal digesta, and di-gestible P for broilers increased linearly with dietary SBM level increasing ( P<0.01) . However, dry matter di-gestibility and apparent P digestibility decreased linearly with dietary SBM levels increased ( P<0.01) . Increas-ing dietary Ca∶P enhanced P output in ileal digesta, thus reduced digestible P and apparent P digestibility ( P<0.01) . The estimated values of TPD in SBM for broilers fed diets with a Ca∶P at 2.0 was 40.79% and 39.84%by the regression method and the difference method, respectively. These values were lower than the values of 53.36% and 55.59% for birds fed diets with a Ca∶P at 1.0 and the values of 56.81% and 56.36% for chickens fed diets with a Ca∶P at 1.5 derived from the regression method and the difference method, respectively ( P<0.05) . In summary, dietary Ca∶P influenced the estimation of TPD in SBM for broiler chickens. However, the determination of TPD was not affected by the calculated methods ( the regression method and the difference method).