Effect of vitamin D3 and/or zeolite supplementation to laying hen rations added microbial phytase on some blood indices 2. total cholesterol,1,25-dihydroxycholecalciferol and oestradiol-17β levels [Mikrobiyal fitaz i̇laveli yumurta tavuǧu rasyonlari{dotless}na D3 vitamini ve/veya zeolit eklenmesinin bazi{dotless} kan parametreleri üzerine etkisi 2. total kolesterol,1,25-dihidroksikolekalsiferol ve östradiol-17β düzeyleri]

The aim of this study was to examine the effect of vitamin d3 and/or zeolite supplementation in the presence of phytase enzyme on serum total cholesterol,1,25-dihydroxycholecalciferol (1,25-(oh)2d3) and oestradiol-17β levels in laying hens. a total of 60 laying hens,28-wkold 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 d3 added group (p<0.05). serum 1,25-(oh)2d3 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-17β 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)2d3 levels,and phytase enzyme and vitamin d3 supplementation increased serum oestradiol-17β levels.