【作者】 宋金彩；

【导师】 单安山；

【作者基本信息】 东北农业大学 ， 动物营养与饲料科学， 2000， 博士

【摘要】 本研究通过体外试验和动物试验，全面系统地研究了微生物植酸酶的特性及其对不同阶段蛋鸡生产性能的影响。体外试验主要研究温度、pH、饲料加工工艺和贮存时间对植酸酶活性的影响，以及微生物植酸酶对玉米、豆粕、麦麸中植酸磷的降解率。动物试验主要研究植酸酶对育雏、生长和产蛋期海赛克斯商品代蛋鸡生产性能、营养物质利用、血清学指标、胫骨强度、胫骨矿物质沉积和骨组织结构的影响。 体外试验表明，微生物植酸酶在37℃条件下，只有一个活性高峰（pH5.0）；其活性随温度升高而升高，而且pH与温度对植酸酶的影响存在明显互作，pH6.2时，植酸酶在45℃活性最高，pH5.4和pH4.6时，其最适温度为55℃，不同pH下，植酸酶在最适温度表现出的活性，远大于标准条件下的活性；适当降低溶液pH，植酸酶最适温度提高，可能是较低的pH有利于植酸酶功能性结构的保持。冷制粒和膨化分别使饲料中植酸酶活性下降39.8％和73.2％，粉料、颗粒料和膨化料在贮存2个月后，其中的植酸酶活性分别损失20.4％、12％和18％，粉料和颗粒料贮存8个月后，植酸酶活性仅剩余16.7%和10.2％。饲料原料植酸磷降解试验表明，300U/kg植酸酶64分钟从玉米、豆粕中释放出16.83mmol/kg和14.56mmol/kg无机磷，45分钟从麦麸中释放出89.4mmol/kg无机磷，分别占原料中植酸磷总量的37.4％、20.5％和62.9％。 动物试验分育雏、生长和产蛋三阶段进行。育雏期试验为期9周，设4个处理，各三个重复；对照组日粮含玉米63.1％、豆粕29％、麦麸4％、磷酸氢钙1.9％、石粉1％、添加剂1％；将磷酸氢钙添加量减至1％，代之以350U/kg植酸酶或去掉全部磷酸氢钙加入0.8％植酸（纯度70％）和350U/kg植酸酶，得处理2、3，处理2制粒为处理4；日粮中钙的减少用石粉补充，剩余空间添加沙石。第9周进行代谢试验和屠宰试验。试验结果表明，低磷和高植酸日粮添加350U/kg植酸酶，使蛋雏鸡的增重、采食量、料重比、血清钙、磷、碱性磷酸酶活性、胫骨强度、胫骨灰分以及胫骨灰分中钙、磷和微量元素含量都达到或超过对照组水平，其中处理3、4的日增重和饲料效率个别高于对照组6.6%、98％和37％、43％，差异显著。植酸酶的添加使植酸磷、铜、铁、锌、锰利用率极显著高于对照，仅植酸添加组粗蛋白、干物质利用率低于对照组。胫骨屈服力、强度、抗弯曲弹性模量、灰分含量等、处理间无差异，证明植酸酶的添加克服了缺磷引起的生长抑制 生长试验对照组（处理1）日粮由63.6％玉米，20％豆粕，1.5％麦麸，15％磷酸氢钙，10％石粉和0.9％添加剂组成，磷酸氢钙降至0.6％并添加0和350U/kg植酸酶，组成处理2、4日粮，将磷酸氢钙用350U/kg全部代替为处理3日粮，处理5（颗粒料）日粮组成同处理4。石粉补钙，沙石填充剩余空间。试期为12-18周龄，其间自14周龄开始限饲。试验结果表明，植酸酶添加组的增重、采食量、饲料利用率达到和超过对照组水平，博士学位论文 微生物植酸酶特性的研究及其在蛋鸡饲粮中的应用 东北农业大学高于低磷不添加植酸酶的处理2，说明植酸酶的添加有效防止了由磷供应不足导致的生长缓慢，血清指标与对照组相仿，仅处理4血磷降低。植酸酶添加组的磷和微量元穿：利用率普遍降低。 产蛋期试验期为20～50周龄，计门处理。日粮含619％玉米，27％豆粕，l％麦鼓。处理l～12磷酸氢钙添加量为l．lO、l．lO、0．19o、l．3O、0．0O、0．650、0．65O、0．650、15％、00％、00％，植酸酶添加量为0、50、300、50、175、175、350、0、175、0． 0、引）OU／kg。于28周龄和50周龄分别测定蛋壳强度，48周龄屠宰，42周龄代谢试验。试验结果表明，不添加植酸酶和无机磷的处理门生产性能最低，日粮含总磷超过 0446％ ＼添加 065％磷酸氢钙）的日粮中添加植酸酶不能提高产蛋率、饲料报酬及蛋壳质量，只有在不加或只添加 of 9％磷酸氢钙的日粮中添加植酸酶才能使生产性能和蛋壳质量提高。在仅含植物性磷的日粮添加 175和 300U／kg植酸酶，使植酸磷利用率大幅度升高，干物质、粗蛋白、粗灰分和总磷利用率有不同程度的改善，产蛋率提高107％和18二％料蛋比下降／0％和 69％，在含 019％磷酸氢钙日粮添加 300U／k植酸酶较50U／kg产蛋吕和饲料报酬均高，但差异不显著。含磷高的处理 5和处理 10生j。‘性能低于含 0 65％和11％磷酸氢钙组的水平。产蛋鸡缺磷会导致生产叶能和蛋壳质量下降，但添加过多良磷或在含较高磷日粮添加植酸酶并无任何优势，仅会导致生产性和蛋壳质量下降，日粮总f4含量0446％－0525％为宜。蛋鸡饲粮添加植酸酶，对血清钙、磷含量及碱性磷酸酶活忙、肚骨强度等基本无影响，却有使钙、铜、铁、锰、锌利用率下降趋势。 本研究结果表明，微生物植酸酶在体内、体外均能有效地降解植酸磷，并促进其他营养物质的利用。育雏期蛋鸡饲粮添加微生物植酸酶，能够提高生产性能和营养物质利用至，生长期饲粮添加植酸酶，增重的提高不显著，但使磷及矿物元素利用率普遍下降。对于产更多还原

【Abstract】 The present study concentrated on the properties of phytase and its effect on the performance of chicken in different stage by in vitro and in vtvo experiment respectively. The in vitro experiment studied the influence of temperature pH, feed processing, and storage on the activity of microbial phytase. The ability of phytase to liberate phytate phosphonis from corn, soybean meal and wheat bran was studied also. The animal trials were conducte~ at rearing, growing and laying stage in order to determine the effect of phytase on performance, nutrient utilization, serum merits, tibia measurements and on histological structure. The in ~ itro experiments showed that the activity of microbial phytase is affected by pH, temperature, processing and storage. At 37C the optima] pH is 5.0. Significant interact existed between temperature and pH. The optimal temperature is 45C for pH6.2 and 55扖 for pH5.4 and pH4.6 The activities of phytase at optimal temperature for different pH are much higher than the relative activity at standard condition. Pellet and extrude decreased phytase activity by 39.8% and 73.2%.The phytase activity in powder. pelleted and extruded feed decreased by20 4%, 12% and 18% after a 2-month period of storage. The degradation experiment showed that 300U/kg phytase liberated 16.83mmol/kg and 14.S6mmol/kg inorganic phosphorus in 64 minutes from corn and soybean meal, the amount of inorganic phosphorus liberated fram ~~heat bran in 45minutes is 89.4mmol/kg, accounting 3 7.4%, 20.5% and 62.9%. of phytate phosphorus.Rearing control diet (diet 1) components were as followings: corn 63.1%, soybean meal 29%, wheat bran 4%, dicalcium phosphate 1.9% limstone mill 1% and premix 1%. 35013/kg phvtase were supplemented to a reduced 1% dicalcium phosphate level(diet 2), or replaced all dicalcium phosphate with 0.8% phytic acid and 35OUikg feed phytase(treatment 3). the decreased Ca were supplement with limestone mill and sand to fulfill the decreased component. Last treatment were pelleted based on diet 2. At age week 9 metabolic test and slaughter test were carried out. With 350U/kg feed phytase , the low P or high phytate groupreach or surpass the control group in all the following measurements including: weight gain, feed intal%e, feed/gain ratio, serum Ca level, serum P level, serum AKP activity, tibia breaking strength1 tibia ash and Ca, P, mineral element in tibia ash. The average daily gain and feed efficiency of treatment 2 & treatment 3 significantly higher than that of control. Phytase supplementation increasd utilization of Phytic P, Cu, Fe, Zn and Mn significantly , the only e抴eption is that high phytic acid diet treatment with lower crude protein and dry matter utilization than that of control. For tibia tested factors there were no difference among treatment in yield force, breaking force, elastic parameter and ash content.The growing test dietary (treatmentl) were composed of: corn 63.6%, soybean meal 2(2/o, x抙eat bran 13%, CaHPO4 1.5%, limestone mill 1.0% and additives 0.9%. Reduce the (IaHPO4 level to 0.6%a and adding phytase OUIkg feed(treatment 2) or 350U/kg feed(treatment 4). or with 350U/kg feed replaced all CaHPO4 (treatment 3) and using CaCO3 to supplement Ca level and sand to fulfill the decreased component. Treatment 5 was pellet diet 4. The trial last from 12 to 18 wk. A restricted feeding program were used from week 14. It can be conclude fl-orm the results that the gain and feed efficiency are similar to or higher than the control抯 when treated with phytase. and higher than treatment 2 which without phvtase. It means that the slow growth should be caused by P deficiency is effectively got out by phytase supplementation. Serum measurements phytase supplemented treatmens matched the control. Only treatment 4 had a lower serum P. Phytase decreased the utilization of minera~s and P !ncreased excretion in Feces.Laying test ages were week 20-50 with 12 treatment. The basic ration was as follows: corn 61.9%, soybean meal 27% and wheat bran 1%. The CaHPO4 levels included in更多还原