An experiment was conducted to evaluate correlations between in vitro phytase activity after pelleting and broiler performance, tibia mineralization, and plasma myo-inositol of broilers fed diets containing different phytase enzymes conditioned at 3 different temperatures (70°C, 80°C, and 90°C). Dietary treatments included a positive control (0.9% calcium [Ca] and 0.4% nonphytate phosphorus [nPP]) and negative control (NC; 0.7% Ca and 0.2% nPP) and 4 additional diets containing commercially available phytase products (A, B, C, and D) added to the NC based on analyzed activity and manufacturer's recommendations. Treatments were arranged in a 6 (diet formulation) × 3 (conditioning temperature) factorial in a randomized complete block design, with 10 replications of 10 male broilers fed each of 18 dietary treatments for 21 D. Correlations were determined with categorical and replicated data. A conditioning temperature × diet formulation interaction occurred for day 14 and 21 feed conversion ratio (FCR) and day 21 tibia ash (P < 0.05). Day 14 and 21 FCR increased, and day 21 tibia ash decreased as conditioning temperature was increased from 70°C to 90°C for all phytase treatments except phytase B that did not demonstrate performance or tibia ash detriment. Correlations were most apparent with replicated data. In vitro phytase A activity correlated with day 21 FCR (P = 0.04, r = −0.38), phytase B did not demonstrate correlation (P > 0.05), phytase C correlated with tibia ash mg/chick (P = 0.01, r = 0.46), and phytase D showed a moderate correlation with tibia ash mg/chick (P = 0.16, r = 0.26) and plasma myo-inositol concentration (P = 0.15, r = 0.27). This study did not demonstrate a common in vivo performance metric that was correlated with in vitro phytase activity after manufacture among commercial phytase products that decreased in activity because of increased conditioning temperature. Both in vivo and in vitro measurements should be assessed to properly evaluate the efficacy of an enzyme.

进行了一项实验，以评估在3种不同温度（70°C，80°C和90°C的条件下）饲喂含有不同肌醇六磷酸酶的肉鸡日粮后体外植酸酶活性与肉鸡生产性能，胫骨矿化和血浆肌醇之间的相关性。°C）。饮食治疗包括阳性对照（0.9％钙[ Ca ]和0.4％非植酸磷[ nPP]）和阴性对照（NC； 0.7％Ca和0.2％nPP），以及根据分析的活性和制造商的建议，在NC中添加了另外4种日粮，这些日粮中含有市售的植酸酶产品（A，B，C和D）。在随机完整区组设计中按6（饮食配方）×3（调节温度）因子进行处理，对10只雄性肉鸡进行10次重复试验，分别饲喂18种日粮处理21D。通过分类和重复数据确定相关性。第14天和第21天饲料转化率（FCR）和第21天胫骨灰分（P <0.05）。第14天和第21天的FCR增加，而第21天胫骨灰分减少，这是因为除了未表现出性能或胫骨灰分有害的植酸酶B外，所有植酸酶处理的调节温度从70°C升高至90°C。相关性在复制数据中最为明显。体外植酸酶A活性与第21天FCR相关（P  = 0.04，r  = -0.38），植酸酶B未显示出相关性（P  > 0.05），植酸酶C与胫骨灰分毫克/小鸡相关（P  = 0.01，r  = 0.46 ），植酸酶D与胫骨灰分毫克/小鸡（P  = 0.16，r  = 0.26）和血浆肌醇浓度（P = 0.15，r  = 0.27）。这项研究没有证明在商业植酸酶产品中，由于调节温度升高而活性降低，因此与生产后的体外植酸酶活性相关的共同的体内性能指标。两者在体内和体外测量应该进行评估，以正确地评估的酶的功效。