ABSTRACT
Seventy-five White Leghorn hens during peak egg laying cycle were randomly divided into 5 groups: 1 group with 0.32% NPP (control), 2 groups with 0.24% NPP and laboratory (T1) or commercial (T2) phytase (250 FTU/kg feed), and 2 groups with 0.16% NPP and laboratory produced (T3) or commercial (T4) phytase (500 FTU/kg feed) from 23 to 40 weeks of age. The results indicated T2 group had the lowest (P > 0.05) bone ash, followed by similar ash content in T1, T3 and control groups. Mineral concentration (Ca, P, zinc and manganese) in the bone was not affected (P > 0.05) by variation in dietary phytase and NPP level. In duodenum, NaPiIIb was up-regulated (P < 0.05) in T2 and T3, whereas Calbindin 1 (CALB1) was up-regulated (P < 0.05) only in T3. In kidney, expression of NaPiIIa and CALB1 were down-regulated (P < 0.05) in all groups. The data demonstrated that 250 FTU/kg laboratory phytase supplementation in feed was enough for replacing 50% of inorganic P and 500 FTU/kg commercial phytase capable of replacing 100% of inorganic P. The up-and down-regulation of NaPiIIb, NaPiIIa and CALB1 genes in treatment groups was independent of phytase source and NPP level in feed.
Acknowledgments
This work was supported by the Department of Biotechnology, Government of India is thankfully acknowledged.
Disclosure statement
There was no conflict of interest among the authors.