植酸酶和木聚糖酶对仔猪钙、磷代谢及骨骼发育的影响

试验采用完全随机设计，将90头35日龄断奶仔猪分为5组，每组设3个重复，每个重复6头，研究在饲粮中添加植酸酶和木聚糖酶对断奶仔猪钙、磷代谢及骨骼发育的影响。5组分别饲喂：①玉米-豆粕基础饲粮（正对照组，PC）；②基础饲粮降低75％磷酸氢钙（负对照组，NC）；③负对照组饲粮＋植酸酶（植酸酶组，phy）；④负对照组饲粮＋木聚糖酶（木聚糖酶组，xy）；⑤负对照组饲粮＋植酸酶＋木聚糖酶（植酸酶-木聚糖酶组，pay—xy），植酸酶的添加量为750U·kg^-1，木聚糖酶的添加量为4000U·kg^-1。结果表明：单独添加植酸酶和木聚糖酶或两者同时添加均使磷消化率极显著提高（P〈0.01）、排出量显著降低（P〈0．05），血液磷浓度达到正常磷水平；添加酶的各组钙的消化率显著高于负对照组（植酸酶组、植酸酶一木聚糖酶组P〈0．01；木聚糖酶组P〈0．05）；添加酶的各组猪掌骨灰分均显著高于负对照组（P〈0．05），但与正对照组无显著差异；添加植酸酶或木聚糖酶仔猪的酿骨强度均显著高于负对照组（P〈0．05），但木聚糖酶组猪的跟骨强度仍显著低于采食正常磷饲粮的正对照组（P〈0．05）。因此，在断奶仔猪低磷饲粮中添加植酸酶或木聚糖酶都不同程度地促进了钙、磷的消化利用和骨骼生长，但两种酶同时添加没有显著的协同效应。

Effects of Phytase and Xylanase Supplementation to Diets on Metabolism of Ca,P and Bone Development in Piglets

The experiment was conducted to evaluate the effects of phytase and xylanase supplementation to diet of weaned pigs on metabolism of Ca, P and bone development. This experiment was in a complete randomized design. Ninety healthy piglets were divided into five groups with three replicates, each of which in cluding 6 piglets. The treatments were respectively： （1）Corn-soybean meal basal diet（CSBM）. （2） CSBM basal diet deficient in CaHPO4 （Negative control group）. （3）Negative control diet with phytase added （Phytase group）, （4） Negative control diet with xylanase added （Xylanase group）. （5）Negative control diet with a combination of phytase and xylanase added （Phytase-Xylanase group）. The addition of phytase and xylanase were 750 U·kg^-1 and 4 000 U·kg^-1 respectively. Addition of phytase and xylanase alone or the combination of the two enzymes imprived P digestibili ty significantly （P〈0.01）, reduced fecal P excretion （P〈0.05）, maintained normal serum P level. Ca digestibility and metacarpal bone ash in groups of adding enzyme were higher than that of negative control group（P〈0.05）, and there was no significant difference in groups of adding enzyme and positive control group. The metatarsal bone strength in phytase group and xylanase group were significantly higher than that of negative control group（P〈0.05）, while the metatarsal bone strength in xylanase group was significantly lower than that of positive control group （P〈 0.05）. In conclusion, Phytase or xylanase supplementation in diets deficient in available P of weaned pigs improved Ca, P digestion and utilization, improved bone development, but no synergistic effect between the two enzymes was noted.