The Effect of Selected Feed Additives on the Shell Qualitative Parameters of Table Eggs

Abstract

Herbs, spices and their extracts (botanicals) have a wide range of activities. It may have a beneficial effect on the gastrointestinal micro flora of animals, performance and quality of animal products. In this experiment the effects of supplementation of the diet for laying hens with different doses of thyme or oregano essential oil addition on egg shell quality parameters were studied. Hens of laying hybrid Hy-Line Brown (n=50) were randomly divided into 5 groups (n=10) and fed for 20 weeks with diets with thyme or oregano essential oil supplemented. In the control group hens received feed mixture with no additions. The diets in the first and second experimental groups were supplemented with 0.5 ml/kg or 1.0 ml/kg thyme essential oil. The diets in the third and fourth experimental groups were supplemented with 0.5 ml/kg or 1.0 ml/kg oregano essential oil. The egg shell weight (g), specific egg shell weight (g/cm3), percentage of egg shell (%), egg shell strength (N/cm2) and egg shell thickness (mm) were evaluated. The egg shell weight for the whole period was in the order of the groups 5.70±0.52; 5.65±0.44; 5.54±0.42; 5.62±0.38 and 5.49±0.48 g±S.D (P>0.05). Egg shell strength during the reporting period was in order of the groups: 27.81±6.00; 27.63±6.43; 27.17±6.36; 27.76±6.27 and 28.41±6.36 (N/cm2±S.D). Similarly, in the egg shell specific weight (g/cm3), egg shell percentage ratio (%) and egg shell thickness (mm) were observed statistically non-significant differences compared to the control group (P>0.05). The results suggest that the qualitative parameters of egg shell were not significantly influenced with thyme or oregano oil addition (P>0.05).

Keywords

• egg shell
• essential oil
• oregano
• quality
• thyme