Effects of Rosemary (Rosmarinus officinalis L.), Onion (Allium cepa L.) Extracts and their Mixtures on White Leghorn Layers Performance and Blood Profile

Introduction: The consumer’s requirements for the highest quality animal products should be achieved by the application of appropriate health-safe animal diets. The study was conducted to evaluate the effects of rosemary and onion extracts on performances, and some hematological and serum biochemical parameters of White Leghorn. Materials and methods: One hundred twenty White Leghorn layers at 32 weeks of age were randomly allocated to four treatments each replicated three times with ten layers and one cock per replication and managed on a deep litter system for 70 days. The treatments were control group without any addition of feed additives (T1), basal diet supplemented with 4 milliliters of onion extract in water (T2), basal diet supplemented with 4 milliliters of rosemary extract in water (T3), and basal diet supplemented with 4 milliliters of onion and rosemary extract mixture in water (T4). The data on performance parameters such as feed intake, body weight change body weight gain, feed conversion ratio, egg production, egg mass, and serum biochemistry and hematology were evaluated. Results: The daily feed intake of chickens in T2 was significantly higher than the feed intake of chickens in T1, T3, and T4. There was no significant difference in packed cell volume percentage but there was a significant difference in total serum cholesterol in T1 compared to T4. Layers supplemented with onion extract had lower blood total cholesterol levels compared to other groups. Results revealed that the use of onion extract (T2) in drinking water recorded significantly higher daily feed intake, body weight change, and gain compared to other groups. Layers fed on onion blended with rosemary extract in drinking water recorded the highest feed conversion compared to T1, T2, and T3 treatments. Conclusion: The use of rosemary, onion extracts, and their mixtures in drinking water significantly influenced most of the studied hematological and serum biochemical parameters of White Leghorn layers except packed cell volume and serum albumin.