Veum T L, Bollinger D W, Buff C E, Bedford M R
Department of Animal Sciences, University of Missouri, Columbia, 65211, USA.
J Anim Sci. 2006 May;84(5):1147-58. doi: 10.2527/2006.8451147x.
A 28-d experiment was conducted using 126 crossbred barrows to evaluate the addition of a genetically engineered Escherichia coli phytase to diets that were 0.15% deficient in available P. Growth performance, bone strength, ash weight, and the apparent absorption of P, Ca, Mg, N, energy, DM, Zn, Fe, and Cu were the response criteria. The pigs (2 pigs/pen) averaged 7.61 kg of BW and 30 d of age initially. The low-P basal diet was supplemented with 0, 100, 500, 2,500, or 12,500 units (U) of E. coli phytase/kg of diet, or 500 U of Peniophora lycii phytase/kg of diet. The positive control (PC) diet was adequate in available P. Pigs were fed the diets in meal form. Fecal samples were collected from each pig from d 22 to 27 of the experiment. There were linear and quadratic increases (P < 0.001) in 28-d growth performance (ADFI, ADG, and G:F), bone breaking strength and ash weight, and the apparent absorption (g/d and %) of P, Ca, and Mg (P < or = 0.01 for quadratic) with increasing concentrations of E. coli phytase. Pigs fed the low-P diets containing 2,500 or 12,500 U/kg of E. coli phytase had greater (P < or = 0.01 or P < 0.001, respectively) values for growth performance, bone breaking strength and ash weight, and the apparent absorption (g/d and %) of P, Ca, and Mg than pigs fed the PC diet. The addition of E. coli phytase did not increase the apparent percentage absorption of N, GE, DM, Zn, Fe, or Cu. There were no differences in the efficacy of the E. coli or P. lycii phytase enzymes at 500 U/kg of low-P diet for any criterion measured. In conclusion, there were linear increases in growth performance, bone breaking strength and ash weight, and the apparent absorption of P, Ca, and Mg with increasing addition of E. coli phytase up to 12,500 U/kg of diet. Also, all of these criteria were greater for pigs fed the low-P diets containing 2,500 or 12,500 U of E. coli phytase/kg than for pigs fed the PC diet. The addition of 500, 2,500, or 12,500 U of E. coli phytase/kg of low-P diet reduced P excretion (g/d) in manure by 35, 42, and 61%, respectively, compared with pigs fed the PC diet.
进行了一项为期28天的试验，使用126头杂交公猪来评估在有效磷含量低0.15%的日粮中添加基因工程大肠杆菌植酸酶的效果。生长性能、骨强度、灰分重量以及磷、钙、镁、氮、能量、干物质、锌、铁和铜的表观吸收率作为反应指标。试验开始时，猪（每栏2头）平均体重7.61千克，年龄30天。低磷基础日粮分别添加0、100、500、2500或12500单位（U）/千克日粮的大肠杆菌植酸酶，或500 U/千克日粮的茯苓属植酸酶。阳性对照（PC）日粮的有效磷含量充足。猪以粉料形式饲喂日粮。在试验的第22至27天，从每头猪采集粪便样本。随着大肠杆菌植酸酶浓度的增加，28天的生长性能（平均日采食量、平均日增重和料重比）、骨断裂强度和灰分重量以及磷、钙和镁的表观吸收率（克/天和%）呈线性和二次增加（P<0.001）（二次项P≤0.01）。饲喂含2500或12500 U/千克大肠杆菌植酸酶的低磷日粮的猪，其生长性能、骨断裂强度和灰分重量以及磷、钙和镁的表观吸收率（克/天和%）的值比饲喂PC日粮的猪更高（分别为P≤0.01或P<0.001）。添加大肠杆菌植酸酶并未增加氮、总能、干物质、锌、铁或铜的表观吸收率。对于所测定的任何指标，在低磷日粮中添加500 U/千克的大肠杆菌或茯苓属植酸酶，其效果没有差异。总之，随着日粮中大肠杆菌植酸酶添加量增加至12500 U/千克，生长性能、骨断裂强度和灰分重量以及磷、钙和镁的表观吸收率呈线性增加。此外，饲喂含2500或12500 U/千克大肠杆菌植酸酶的低磷日粮的猪，所有这些指标均高于饲喂PC日粮的猪。与饲喂PC日粮的猪相比，在低磷日粮中添加500、2500或12500 U/千克的大肠杆菌植酸酶，分别使粪便中磷排泄量（克/天）降低了35%、42%和61%。
