不同植酸酶理化性能及肉鸡应用效果研究

The Physicochemical Properties of Different Phytase and Application in Broilers

本研究选用七种不同植酸酶产品,通过粒度分布、水分、灰分、容重、耐热性、体外对植酸磷的释放效应等方面进行不同植酸酶物理特性的评估,同时在零无机磷的极端饲料配方下,观察不同植酸酶对肉鸡生长性能和胫骨发育的影响,以综合评估不同植酸酶的功效。结果表明:不同植酸酶的几何平均粒径无差异(P>0.05),但算术平均粒径和粒度模数差异显著(P<0.001),植酸酶A、B、F和G颗粒可能更细更集中;水分、灰分含量和容重差异显著(P<0.05),植酸酶A和F更有益于在配合饲料中的混合和均匀分布;不同植酸酶耐热性能不同(P<0.001),A和G表现更好;体外酶解释放磷的效果差异极显著(P<0.01),植酸酶A的体外磷释放率较高;相比于其他植酸酶,肉鸡饲粮中添加植酸酶A,能够极显著提高肉鸡采食量(P<0.01),且有提高期末体重和平均日增重的趋势(P=0.083)。此外,处理A表现出了更大的肉鸡胫骨重(P<0.05)。不同植酸酶产品理化特性比较及在肉鸡上的实际饲喂效果存在差异,可见,对植酸酶的评估不能从单一方面(如耐热性)考虑,应综合植酸酶的粒度分布和均匀度、耐热性能、肉鸡生长性能和养分释放效应以及胫骨发育等指标科学系统评估。

The present study is to investigate the physical and chemical properties of seven different phytase products through the assay of particle size distribution,moisture,crude ash,unit weight,heat resistance,and phytate phosphorus releasing effects in vitro.At the same time,the effects of phytase on growth performance and tibia development of broilers were observed under the extreme feed formula of zero inorganic phosphorus to evaluate the efficacy of phytase comprehensively.The result showed that:There was no difference(P>0.05)in geometric mean particle size,but significant difference in arithmetic mean particle size and modulus grading(P<0.001),and the particle size of phytase A,B,F and G may be more small and intensive.The moisture,crude ash and unit weight were different(P<0.05)among the seven phytase products,and the phytase A and F had better mixing uniformity.The better heat-resisting property was observed(P<0.001)in phytase A and G.The significant difference in phytate phosphorus releasing effects in vitro was indicated in this study(P<0.001),and the phytase A had higher effects.compared to other phytase products,broilers fed diets with phytase A had higher average daily feed intake(P<0.01)and tibia weight(P<0.05),tended(P=0.083)to have higher 28d body weight and average daily gain.In conclusion,there was significant difference in physicochemical properties,and application effects in broilers among the seven phytase products.Therefore,the efficacy of phytase could be indicated by particle size distribution,growth performance,nutrient releasing effects and tibia growth of broilers not merely heat-resistance.