Shet Divya, Ghosh Jyotirmoy, Ajith Sreeja, Awachat Vaibhav B, Elangovan Arumbackam V
ICAR - National Institute of Animal Nutrition and Physiology, Bangalore 560030, India.
Department of Biotechnology, Jain University, Bangalore 560030, India.
Anim Nutr. 2018 Mar;4(1):52-58. doi: 10.1016/j.aninu.2017.10.004. Epub 2017 Oct 28.
This study was conducted to evaluate the effects of different levels of dietary phytase supplementation in the layer feed on egg production performance, egg shell quality and expression of osteopontin () and calbindin () genes. Seventy-five White Leghorn layers at 23 weeks of age were randomly divided into 5 groups consisting of a control diet with 0.33% non-phytate phosphorus (NPP) and 4 low phosphorus (P) diets: 2 diets (T1 and T2) with 0.24% NPP + 250 FTU/kg laboratory produced phytase or commercial phytase and another 2 diets (T3 and T4) with 0.16% NPP + 500 FTU/kg laboratory produced phytase or commercial phytase with complete replacement of inorganic P. The results indicated that there were no significant differences ( > 0.05) in egg production performance and quality of egg during the first 2 months of trial. However, in next 2 months, a significant drop in egg production and feed intake was observed in birds fed diets with low P and 500 FTU/kg supplementation of laboratory produced phytase. Osteopontin gene was up-regulated whereas the gene was down regulated in all phytase treatment groups irrespective of the source of phytase. The current data demonstrated that 250 FTU/kg supplementation of laboratory produced phytase with 50% less NPP supplementation and 500 FTU/kg supplementation of commercial phytase even without NPP in diet can maintain the egg production. The up-regulation of and down regulation of in egg shell gland in the entire phytase treated group birds irrespective of the source of enzymes is indicative of the changes in P bio-availability at this site.
本研究旨在评估蛋鸡饲料中添加不同水平的植酸酶对产蛋性能、蛋壳质量以及骨桥蛋白（）和钙结合蛋白（）基因表达的影响。将75只23周龄的白来航母鸡随机分为5组，一组为含0.33%非植酸磷（NPP）的对照日粮，另外4组为低磷（P）日粮：2组日粮（T1和T2）含0.24% NPP + 250 FTU/kg实验室生产的植酸酶或商业植酸酶，另外2组日粮（T3和T4）含0.16% NPP + 500 FTU/kg实验室生产的植酸酶或商业植酸酶，且完全替代无机磷。结果表明，在试验的前2个月，产蛋性能和蛋品质方面无显著差异（>0.05）。然而，在接下来的2个月中，饲喂低磷日粮且添加500 FTU/kg实验室生产植酸酶的鸡群产蛋量和采食量显著下降。无论植酸酶来源如何，在所有植酸酶处理组中骨桥蛋白基因上调而基因下调。当前数据表明，添加250 FTU/kg实验室生产的植酸酶且NPP添加量减少50%，以及添加500 FTU/kg商业植酸酶（即使日粮中无NPP）均可维持产蛋量。在整个植酸酶处理组的母鸡中，无论酶的来源如何，蛋壳腺中基因的上调和基因的下调表明该部位磷的生物利用率发生了变化。
