Becker Larissa L, Wensley Madie R, DeRouchey Joel M, Woodworth Jason C, Tokach Mike D, Goodband Robert D, Gebhardt Jordan T, Raab R Michael, Lessard Philip A
Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS 66506-0201, USA.
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-0201, USA.
Transl Anim Sci. 2021 Jun 10;5(3):txab105. doi: 10.1093/tas/txab105. eCollection 2021 Jul.
The objective of this study was to determine the available P () release curve for a new phytase source, GraINzyme Phytase (Agrivida Inc., Woburn, MA), which is expressed in corn containing an engineered phytase called Phy02. Plant-expressed phytases are created by inserting phytase-encoding genes into plants resulting in their ability to produce seeds with increased concentrations of phytase. A total of 360 pigs (Line 200 × 400, DNA, Columbus, NE, initially 9.9 ± 0.19 kg) were used in a 21-d growth study. Pigs were weaned at approximately 21 d of age, randomly allotted to pens based on initial body weight () and fed common starter diets. From days 18 to 21 postweaning, all pigs were fed a diet containing 0.11% aP. On day 21 postweaning, considered day 0 of the study, pens were blocked by BW and randomly allotted to one of eight dietary treatments with five pigs per pen and nine pens per treatment. Dietary treatments were formulated to include increasing aP derived from either an inorganic P source (0.11%, 0.19%, or 0.27% from monocalcium P) or increasing phytase (150, 250, 500, 1,000, or 1,500 FTU/kg). Diets were corn-soybean meal-based and contained 1.24% standardized ileal digestible Lys. On day 21 of the trial, one pig per pen (weighing closest to the mean pen BW) was euthanized and the right fibula was collected to determine bone ash using the nondefatted processing method. Overall (days 0 to 21), pigs fed increasing aP from inorganic P or phytase had increased (linear, 0.002) average daily gain (), average daily feed intake (), and gain-to-feed (; quadratic, 0.05). Bone ash weight (g) and percentage bone ash increased (linear, < 0.001), with increasing inorganic P or added phytase. Based on the composition of the diets used in this study, the release equations developed for GraINzyme for ADG, G:F, bone ash weight, and percentage bone ash are as follows: aP = (0.255 × FTU)/(1299.969 + FTU), aP = (0.233 × FTU)/(1236.428 + FTU), aP = (45999.949 × FTU)/(462529200 + FTU), and aP = (0.272 × FTU)/(2576.581 + FTU), respectively.
本研究的目的是确定一种新型植酸酶来源——谷物酶植酸酶（Agrivida公司，马萨诸塞州沃本）的有效磷（aP）释放曲线，该植酸酶在含有一种名为Phy02的工程植酸酶的玉米中表达。植物表达的植酸酶是通过将植酸酶编码基因插入植物中产生的，从而使其能够生产出植酸酶浓度增加的种子。在一项为期21天的生长研究中，共使用了360头猪（200×400品系，DNA，内布拉斯加州哥伦布市，初始体重9.9±0.19千克）。猪在约21日龄时断奶，根据初始体重随机分配到栏中，并饲喂普通的起始日粮。在断奶后第18至21天，所有猪都饲喂含0.11%有效磷的日粮。在断奶后第21天，即研究的第0天，根据体重对栏进行分组，并随机分配到八种日粮处理之一，每栏五头猪，每种处理九个栏。日粮处理的配方包括增加来自无机磷源（来自磷酸二氢钙的0.11%、0.19%或0.27%）的有效磷或增加植酸酶（150、250、500、1000或1500 FTU/kg）。日粮以玉米-豆粕为基础，含有1.24%的标准回肠可消化赖氨酸。在试验的第21天，每栏一头猪（体重最接近栏平均体重）实施安乐死，并采集右侧腓骨，使用非脱脂处理方法测定骨灰。总体而言（第0至21天），饲喂来自无机磷或植酸酶的有效磷增加的猪，平均日增重（ADG）、平均日采食量（ADFI）和料重比（G:F）均增加（线性，P<0.002）；骨灰重量（克）和骨灰百分比增加（线性，P<0.001），无机磷或添加植酸酶增加。根据本研究中使用的日粮组成，为谷物酶植酸酶开发的关于ADG、G:F、骨灰重量和骨灰百分比的释放方程如下：aP = (0.255 × FTU)/(1299.969 + FTU)、aP = (0.233 × FTU)/(1236.428 + FTU)、aP = (45999.949 × FTU)/(462529200 + FTU)和aP = (0.272 × FTU)/(2576.581 + FTU)。
