Kiarie E, Woyengo T, Nyachoti C M
DuPont Industrial Bioscience-Danisco Animal Nutrition, Marlborough, Wiltshire, SN8 1XN, UK ; Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada .
Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada . ; Department of Animal Science, South Dakota State University, Brooking, SD, 5700, USA .
Asian-Australas J Anim Sci. 2015 Oct;28(10):1479-87. doi: 10.5713/ajas.15.0059.
A total of 420 day-old male Ross chicks were weighed at d 1 of life and assigned to test diets to assess the efficacy of a new Buttiauxella spp. phytase expressed in Trichoderma reesei. Diets were: positive control (PC) adequate in nutrients and negative control (NC) diet (40% and 17% less available phosphorous (P) and calcium (Ca), respectively) supplemented with 6 levels of phytase 0, 250, 500, 750, 1,000, and 2,000 phytase units (FTU)/kg of diet. All diets had titanium dioxide as digestibility marker and each diet was allocated to ten cages (6 birds/cage). Diets were fed for 3 wk to measure growth performance, apparent retention (AR) on d 17 to 21 and bone ash and ileal digestibility (AID) on d 22. Growth performance and nutrient utilization was lower (p<0.05) for NC vs PC birds. Phytase response in NC birds was linear (p<0.05) with 2,000 FTU showing the greatest improvement on body weight gain (20%), feed conversion (7.4%), tibia ash (18%), AR of Ca (38%), AR of P (51%) and apparent metabolizable energy corrected for nitrogen (5.1%) relative to NC. Furthermore, phytase at ≥750 FTU resulted in AID of total AA commensurate to that of PC fed birds and at ≥1,000 FTU improved (p<0.05) AR of P, dry matter, and N beyond that of the lower doses of phytase and PC diet. In conclusion, the result from this study showed that in addition to increased P and Ca utilization, the new Buttiauxella phytase enhanced growth performance and utilization of other nutrients in broiler chickens in a dose-dependent manner.
总共420只1日龄的罗斯雄性雏鸡在出生第1天称重，并分配到不同的试验日粮中，以评估在里氏木霉中表达的一种新型布蒂亚克氏菌属植酸酶的功效。日粮如下：营养充足的阳性对照（PC）日粮和阴性对照（NC）日粮（分别比有效磷（P）和钙（Ca）少40%和17%），补充6个水平的植酸酶，分别为0、250、500、750、1000和2000植酸酶单位（FTU）/千克日粮。所有日粮都添加二氧化钛作为消化率标记物，每种日粮分配到10个笼子（每个笼子6只鸡）。日粮饲喂3周，以测量生长性能，在第17至21天测量表观存留率（AR），在第22天测量骨灰和回肠消化率（AID）。与PC组鸡相比，NC组鸡的生长性能和营养利用率较低（p<0.05）。NC组鸡对植酸酶的反应呈线性（p<0.05），2000 FTU的植酸酶对体重增加（20%）、饲料转化率（7.4%）、胫骨骨灰（18%）、钙的AR（38%）、磷的AR（51%）和氮校正表观代谢能（5.1%）的改善最大，相对于NC组。此外，≥750 FTU的植酸酶使总氨基酸的AID与饲喂PC日粮的鸡相当，≥1000 FTU时，磷、干物质和氮的AR相对于较低剂量的植酸酶和PC日粮有所改善（p<0.05）。总之，本研究结果表明，除了提高磷和钙的利用率外，新型布蒂亚克氏菌属植酸酶还以剂量依赖的方式提高了肉鸡的生长性能和其他营养物质的利用率。
