Schmeisser J, Séon A-A, Aureli R, Friedel A, Guggenbuhl P, Duval S, Cowieson A J, Fru-Nji F
DSM Nutritional Products France SA, Saint-Louis, France.
DSM Nutritional Products Ltd, Kaiseraugst, Switzerland.
J Anim Physiol Anim Nutr (Berl). 2017 Jun;101(3):563-575. doi: 10.1111/jpn.12482. Epub 2016 Feb 8.
The effect of phytase on phosphorus retention, broiler (Gallus gallus) performance and bone mineralization in diets with reduced inorganic phosphate concentration is well documented. Furthermore, so-called 'extra-phosphoric' effects of phytase have been described in the literature that may be associated with changes in mineral and amino acid partitioning and requirements per se. In particular, the role of myo-inositol in phytase responses is implied but not well elucidated. It was the purpose of the experiment reported herein to explore the effect of phytase on broiler growth, nutrient digestibility, blood biochemistry and gene expression. A 5-week broiler floor pen trial was conducted to evaluate the effect of supplementation of a moderately phosphorus-deficient diet with 1000 U/kg of a 6-microbial phytase. Parameters measured were growth performance, phosphorus (P), calcium (Ca) and myo-inositol plasma concentrations, apparent ileal P digestibility, bone mineralization, breast meat weight and Pectoralis major muscle transcriptome. Supplementation of the diet with phytase improved weight gain during the starter period (18%) and the whole period (24%) compared with animals that received the control diet (p < 0.05). Improved feed conversion ratio, increased myo-inositol plasma concentration, tibia ash contents and breast meat weight were also observed in animals fed phytase. The transcriptomic analysis revealed that some differentially expressed genes (DEG) in broilers, receiving phytase in comparison with animals fed reduced phosphorus diet without phytase, were part of pathways involved in muscle development, via calmodulin/calcineurin and insulin-like growth factor. Microarray data confirmation was performed on six genes by quantitative PCR (qPCR): PI3K regulatory and catalytic subunit, Phospholipase C beta, Myocyte Enhancer Factors 2A and 2C, and calcineurin A. The results suggested that dietary supplementation with this phytase could generate low molecular weight phytate esters and indirectly myo-inositol, and could help us to understand how muscle metabolism may be affected at a gene level.
植酸酶对低无机磷浓度日粮中磷保留、肉鸡（家鸡）生产性能及骨矿化的影响已有充分记载。此外，文献中还描述了植酸酶所谓的“额外磷效应”，这可能与矿物质和氨基酸分配及需求本身的变化有关。特别是，肌醇在植酸酶反应中的作用虽有暗示但尚未得到充分阐明。本文报道的实验目的是探究植酸酶对肉鸡生长、养分消化率、血液生化指标及基因表达的影响。进行了一项为期5周的肉鸡地面平养试验，以评估在中度缺磷日粮中添加1000 U/kg的6 - 微生物植酸酶的效果。测定的参数包括生长性能、磷（P）、钙（Ca）和肌醇血浆浓度、回肠表观磷消化率、骨矿化、胸肉重量和胸大肌转录组。与接受对照日粮的动物相比，日粮中添加植酸酶可提高雏鸡期（18%）和全期（24%）的体重增加（p < 0.05）。在饲喂植酸酶的动物中还观察到饲料转化率提高、肌醇血浆浓度增加、胫骨骨灰含量和胸肉重量增加。转录组分析表明，与饲喂低磷日粮但未添加植酸酶的动物相比，添加植酸酶的肉鸡中一些差异表达基因（DEG）参与了通过钙调蛋白/钙调磷酸酶和胰岛素样生长因子参与肌肉发育的途径。通过定量PCR（qPCR）对六个基因进行了微阵列数据确认：PI3K调节和催化亚基、磷脂酶Cβ、肌细胞增强因子2A和2C以及钙调磷酸酶A。结果表明，日粮中添加这种植酸酶可产生低分子量植酸酯并间接产生肌醇，并有助于我们了解肌肉代谢在基因水平上可能受到的影响。
