Effects of dietary guar meal with or without beta-mannanase on the egg yolk fatty acids, cholesterol, and some blood parameters of laying hens

In this study, the effects of adding enzyme to the diets containing guar meal (GM) on the egg yolk fatty acids, cholesterol, and some blood plasma parameters of hens were examined. This study was carried out in the chicken coop of the Experimental Animals Ethics Committee, Faculty of Agriculture. This study constitutes the second phase of the study titled "Effects of dietary guar meal with or without beta-mannanase on performance and egg quality traits in laying hens", previously published. The experimental period lasted 126 days. Ninety-six Lohman Brown hens at the age of 56 weeks were and kept in individual cages. They were divided into 8 treatment groups as of: 0% guar meal (GM0) (control); 0% GM + 0.05% beta-mannanase (GM0E), 8% GM (GM8), %8 GM + 0.05% beta-mannanase (GM8E), 16% GM (GM16), 16% GM + 0.05% beta-mannanase (GM16E), 24% GM (GM24) and 24% GM + 0.05% beta-mannanase (GM24E). A lighting period of 16.5 h light and 7.5 h dark was applied throughout the experiment. As a result of the study, it was found that the effects of the treatments on the egg yolk total cholesterol, egg yolk total saturated fatty acids, total unsaturated fatty acids, blood triglyceride, blood glucose, blood total cholesterol, and blood calcium amounts were significant (p < 0.05) and their effects on the blood total protein and blood phosphorus amount were not significant (p > 0.05). According to the results of this study, it was concluded that using up to 8% GM in the diets did not cause a negative effect on the blood parameters of the hens.