Poultry Science Department, University of Arkansas, Fayetteville 72701, USA.
Poult Sci. 2013 Jan;92(1):192-8. doi: 10.3382/ps.2012-02558.
A total of 540 one-day-old male broiler chicks were used to evaluate the potential enhancing effects of a mixture of 2 commercial carbohydrase preparations on phytase efficacy. A nonphytate phosphorus (nPP) deficient diet (0.15%) was supplemented with different levels of phytase (0X, 1X, 2X, and 3X of recommended level of 500 phytase units per kg of feed), individually or in combination with different levels of a mixture of 2 commercial carbohydrase enzymes [0X, 1X, and 2X of recommended level (X = 0.2 g per kg of feed; a mix with predominantly xylanase and β-glucanase activity)] to determine their effects on performance and bone development. A standard response curve was developed using graded levels of nPP (0.15 to 0.45%) from dicalcium phosphate in a diet with no phytase supplementation to estimate the phosphorus equivalency of the different enzyme combinations. Each diet was fed to 6 replicate pens of 5 male chicks from 1 to 18 d of age. Phytase at normal usage levels of 500 phytase units per kg of feed was effective (P < 0.05) in improving BW, increasing feed intake, reducing mortality rate, and increasing toe and tibia ash without significantly influencing feed conversion. Addition of extra levels of phytase (2X and 3X) significantly (P < 0.05) improved toe and tibia ash without further affecting performance traits. The carbohydrase mixture failed to improve performance or enhance phytase efficacy. The phosphorus equivalency of phytase was dose dependent, with estimates of 0.100, 0.123, and 0.213% for 1X, 2X, and 3X supplementation levels of phytase, respectively, based on tibia ash. In conclusion, results indicate that increasing the level of phytase resulted in significant improvements in utilization of dietary nPP, whereas the carbohydrase preparation had no significant effects on performance or had limited effects in enhancing phytase ability in young broiler chicks.
共有 540 只 1 日龄雄性肉鸡雏鸡用于评估 2 种商业酶制剂混合物对植酸酶功效的潜在增强作用。在缺乏非植酸磷（nPP）的日粮（0.15%）中添加不同水平的植酸酶（0X、1X、2X 和 3X 为推荐水平 500 个植酸酶单位/千克饲料），单独或与不同水平的 2 种商业酶制剂混合物（0X、1X 和 2X 为推荐水平（X = 0.2 克/千克饲料；主要含有木聚糖酶和β-葡聚糖酶活性的混合物））组合添加，以确定它们对性能和骨骼发育的影响。通过在不含植酸酶补充的日粮中使用不同水平的二水磷酸氢钙（nPP 从 0.15%到 0.45%）建立标准响应曲线，以估计不同酶组合的磷当量。从 1 日龄到 18 日龄，每种日粮喂食 6 个重复的 5 只雄性小鸡。在饲料中添加正常使用水平的 500 个植酸酶单位/千克饲料，植酸酶能有效（P<0.05）提高体重、增加采食量、降低死亡率，并增加脚趾和胫骨灰分，而不会显著影响饲料转化率。添加额外水平的植酸酶（2X 和 3X）可显著（P<0.05）提高脚趾和胫骨灰分，而不会进一步影响性能性状。该酶混合物未能改善性能或增强植酸酶功效。植酸酶的磷当量与剂量呈依赖性，基于胫骨灰分，1X、2X 和 3X 补充水平的植酸酶的估计值分别为 0.100、0.123 和 0.213%。总之，结果表明，增加植酸酶的水平可显著提高日粮中 nPP 的利用率，而该酶制剂对性能没有显著影响，或在提高肉鸡雏鸡植酸酶能力方面作用有限。
