Department of Poultry Science, Texas A&M University System, College Station, TX 77843-2472, USA.
Poult Sci. 2019 Feb 1;98(2):811-819. doi: 10.3382/ps/pey389.
The present study was conducted to evaluate four commercially available phytase sources supplemented at regular (R) and super-dose (S) levels on live performance, bone mineralization, and apparent ileal digestible energy. Broiler chickens were allocated in stainless steel battery brooders (six birds per cage and eight pen replicates per treatment). A basal diet formulated to contain 0.2% non-phytate phosphorus (NPP) and 0.7% Ca was subdivided to create 11 dietary treatments: (1) basal diet was kept as the negative control (NC); (2) NC + limestone and monoclacium phosphate to create positive controls 1 and 2 formulated to yield 0.3% and 0.4% NPP; (3) NC + phytase A (250 and 1,500 FTU/kg); (4) NC + phytase B (500 and 1,500 FTU/kg); (5) NC + phytase C (500 and 1,000 FTU/kg); (6) NC + phytase D (1,000 and 2,000 FYT/kg). Performance was evaluated on d 7, 14, and 22. Tibia bone ash, tibia breaking strength, bone mineral content, and bone mineral density were evaluated on d 22. Apparent energy digestibility was evaluated on d 24. At d 7, phytases A and C supplemented at S level improved (P < 0.05) body weight and weight gain when compared to the NC. At d 14 and 22, all phytase sources improved (P < 0.05) body weight, weight gain, and bone mineralization when compared to the chicks under the NC diet. Overall, phytase supplementation at S level improved 17% apparent ileal digestibility at 24 d. Throughout the grow out period, phytase super-dose yield (P < 0.05) better performance, bone characteristics, and energy digestibility than the regular dietary level. In conclusion, all phytase sources were able to compensate the phosphorus deficiency and promote performance and bone mineralization. High levels of phytase showed a higher response when compared to the lower levels of supplementation.
本研究旨在评估四种市售植酸酶源在常规（R）和超剂量（S）水平下对肉鸡生产性能、骨骼矿化和回肠表观可消化能的影响。肉鸡被分配到不锈钢电池育雏器中（每笼 6 只鸡，每个处理 8 个重复）。基础日粮配方含有 0.2%非植酸磷（NPP）和 0.7%钙，然后将其分成 11 种日粮处理：（1）基础日粮为负对照（NC）；（2）NC+石灰石和磷酸一钙，配制正对照 1 和 2，使 NPP 含量分别达到 0.3%和 0.4%；（3）NC+植酸酶 A（250 和 1500 FTU/kg）；（4）NC+植酸酶 B（500 和 1500 FTU/kg）；（5）NC+植酸酶 C（500 和 1000 FTU/kg）；（6）NC+植酸酶 D（1000 和 2000 FYT/kg）。在第 7、14 和 22 天评估生产性能。在第 22 天评估胫骨灰分、胫骨断裂强度、骨矿物质含量和骨矿物质密度。在第 24 天评估表观能量消化率。在第 7 天，与 NC 相比，S 水平添加的植酸酶 A 和 C 提高了（P<0.05）体重和体重增重。在第 14 和 22 天，与 NC 日粮下的雏鸡相比，所有植酸酶来源均提高了（P<0.05）体重、体重增重和骨骼矿化。总体而言，在第 24 天，植酸酶 S 水平添加提高了 17%的回肠表观可消化率。在整个生长期间，与常规日粮水平相比，植酸酶超剂量添加（P<0.05）提高了生产性能、骨骼特性和能量消化率。与低水平添加相比，高水平的植酸酶表现出更高的响应。综上所述，所有植酸酶源都能够补偿磷的缺乏，提高生产性能和骨骼矿化。高水平的植酸酶比低水平的添加具有更高的响应。
