Effect of vitamin d-3 and/or zeolite supplementation to laying hen rations added microbial phytase on some blood ındices 2. total cholesterol, 1,25-dihydroxycholecalciferol and oestradiol-17 beta levels

Abstract

The aim of this study was to examine the effect of vitamin D-3 and/or zeolite supplementation in the presence of phytase enzyme on serum total cholesterol, 1,25-dihydroxycholecalciferol (1,25-(OH)(2)D-3) and oestradiol-17 beta levels in laying hens. A total of 60 laying hens, 28-wk-old were separated to 4 equal groups. The hens were fed control diet (300 phytase units (FTU) phytase per kilogram), experimental 1 diet (300 FTU phytase + 400 IU vitamin D3), experimental 2 diet (300 FTU phytase + 400 IU vitamin D3 + 2% zeolite) and experimental 3 diet (300 FTU phytase + 2% zeolite). Serum total cholesterol levels were not statistically different between groups except for week 12. On week 12, these levels were significantly higher in the phytase and zeolite added group than in the phytase and vitamin D-3 added group (P<0.05). Serum 1,25-(OH)(2)D-3 levels were higher in the only phytase added group than in the other groups on week 16 and lower in the phytase and zeolite added group than in the other groups on week 8 (P<0.05). Serum oestradiol-17 beta levels were higher in the phytase and zeolite added group than in the other groups on weeks 4 and 12, and lower in the phytase, vitamin D3 and zeolite added group than in the other groups on week 12 (P<0.05). Consequently, serum total cholesterol levels were not affected by different feeding regimes, phytase enzyme added to ration increased serum 1,25-(OH)(2)D-3 levels, and phytase enzyme and vitamin D-3 supplementation increased serum oestradiol-17 beta levels.