The Effects of Different Levels of Costmary (Tanacetum balsamita) Medicinal Plant on Performance, Egg Traits and Blood Biochemical Parameters of Laying Hens

This experiment was conducted to evaluate the effects of different levels of costmary (Tanacetum balsamita) medicinal plant on performance, egg traits, and blood biochemical parameters of laying hens. Hundred-eighty of Hi-line laying hens (W 36) from 46 until 58 weeks of age were used in a completely randomized design in five treatments and three replicates (12 birds per replicate). The treatment groups consisted of a control group (1) with no costmary supplementation, and 2, 3, 4 and 5 experimental groups with 0.5%, %1, 1.5% and 2% of cost-mary, respectively. Using different levels of costmary significantly affected the performance, egg traits and blood biochemical parameters of laying hens (P < 0.05). The highest and lowest change amounts of daily feed intake (113.47 g) and (99.10 g) were obtained in groups 3 and 1, respectively. The best yolk color index (5.5) was observed in group 3 by using 1% of costmary and the highest Haugh unit (98.75), yolk weight (19.35 g) and albumin weight (36.91 g) were observed in group 5 by using 2% of costmary, whereas the highest percent of egg yolk index (44.66%) was observed in control group. The lowest amounts of blood triglyceride (82.05 mg/dL) and cholesterol (617.2 mg/dL) were observed in groups 5 by using 2% of costmary. The overall results showed that the use of 1.5% and 2% of costmary medicinal plant in the diets of laying hens had positive effects on their performance, egg traits, and blood biochemical parameters.