Department of Animal Science, Federal University of Paraná, Curitiba, Brazil 80035-050.
DSM Nutritional Products, São Paulo, Brazil 03178-200.
Poult Sci. 2021 May;100(5):101050. doi: 10.1016/j.psj.2021.101050. Epub 2021 Feb 16.
An experiment was conducted to evaluate the growth performance, bone mineral composition, diet utilization, and plasmatic concentration of myo-inositol (MYO) in turkeys fed different phytase doses from 1 to 28 d. A total of three hundred and twenty 1-day-old turkeys were distributed in a completely randomized design with 4 treatments and 8 replicates of 10 birds each. Treatments included a basal diet without phytase; reduced diet (reduced -0.15% available P and -0.18% Ca) without phytase; reduced diet + 2,000 units of phytase (FYT)/kg; and reduced diet + 4,000 FYT/kg. From day 26 to 28, partial excreta collection was conducted, and on day 28, 7 birds per replicate were euthanized for collection of ileal content and left tibia bones were removed from 2 of the same euthanized birds. Feed, excreta, and ileal digesta samples were analyzed to determine nutrient digestibility and metabolizability, ileal digestible energy, and AME. Tibia bones were analyzed for ash, Ca, and P content, and calculation of Seedor index. On day 28, blood samples were collected from 2 turkeys per replicate to analyze plasmatic MYO concentration. Feed conversion ratio was not affected, but phytase supplementation resulted in higher feed intake and body weight gain compared to turkeys fed the reduced diet (P < 0.05), and both doses were similar to the basal diet. Increasing the phytase dose had a linear effect (P < 0.05) on ileal digestibility of P and metabolizability of DM, CP, Ca, and Na, and also on AME. P content in the tibia bone increased linearly (P < 0.05) with phytase supplementation, and the same linear increase (P < 0.05) was observed for plasmatic MYO. In conclusion, the supplementation of turkey poult's diets with high levels of phytase up to 4,000 FYT/kg improves diet utilization by increasing P digestibility and dietary metabolizability, leading to higher P content in the bone and enhancing MYO provision and absorption.
一项实验评估了在 1 至 28 日龄阶段，不同植酸酶添加剂量对肉用仔鸡生长性能、骨骼矿物质组成、饲料利用率和肌醇（MYO）血浆浓度的影响。总共 320 只 1 日龄肉仔鸡被随机分为 4 个处理组，每组 8 个重复，每个重复 10 只鸡。处理组包括：基础日粮，不添加植酸酶；低磷低钙日粮（有效磷降低 0.15%，钙降低 0.18%），不添加植酸酶；低磷低钙日粮+2000 单位植酸酶（FYT）/kg；低磷低钙日粮+4000 FYT/kg。从第 26 天至 28 天，进行部分排泄物收集，第 28 天，每个重复随机选取 7 只鸡安乐死，收集回肠内容物，从同批安乐死的 2 只鸡中取出左侧胫骨。对饲料、排泄物和回肠食糜进行分析，以确定养分消化率和代谢率、回肠可消化能和代谢能。对胫骨进行灰分、钙和磷含量分析，并计算硒多尔指数。第 28 天，每个重复随机选取 2 只鸡采集血液，分析血浆肌醇浓度。与饲喂低磷低钙日粮的鸡相比，添加植酸酶并未影响饲料转化率，但显著提高了采食量和体重（P<0.05），且两种剂量均与基础日粮相似。增加植酸酶剂量对磷的回肠消化率和 DM、CP、Ca 和 Na 的代谢率有线性影响（P<0.05），对代谢能也有线性影响。胫骨中磷含量随植酸酶添加呈线性增加（P<0.05），血浆肌醇也呈线性增加（P<0.05）。综上所述，在肉仔鸡日粮中添加高水平植酸酶（高达 4000 FYT/kg）可提高磷的消化率和饲料代谢率，从而增加骨骼中的磷含量，提高肌醇的供应和吸收，改善饲料利用率。
