Dr. D. RAMBABUBOREDDY ASHOK REDDY2023-11-042023-11-042021-12-13BOREDDY ASHOK REDDYhttps://krishikosh.egranth.ac.in/handle/1/5810200380A study was conducted in layers to evaluate the effect of supplementing the microencapsulated essential oil MEEO-I (thymol, carvacrol, and menthol) and MEEO-II (cinnamaldehyde, eugenol, and piperine) on iso-caloric and iso-nitrogenous basis. Two hundred and forty White Leghorn layers (Bovans white) at the age of 22 weeks were randomly allotted to 3 treatments with 20 replicates in each treatment and 4 birds in each replicate. The birds were raised in cage system in an open sided poultry house under uniform management from 22nd to 37th weeks of age. Feed and water were provided ad libitum during the entire experimental period (4 periods of each 28 days from 22 to 37 weeks). A control diet (CD) based on maize and SBM was formulated to contain 16.62% CP and 2625 kcal/kg ME. Two test diets were prepared by supplementing MEEO-I @ 100g/ton of feed and MEEO-II @ 100g/ton of feed. Parameters such as percent hen day egg production, feed intake, feed efficiency per dozen eggs, egg weight, egg mass, body weight, egg quality parameters (Haugh unit, albumen index, yolk index, yolk color, eggshell weight, eggshell thickness, eggshell percentage and shell breaking strength), serum biochemical parameters, livability and feed cost per egg mass were measured. During the overall period (from 22 to 37 weeks of age) percent hen day egg production was significantly (P<0.05) influenced by supplementation of MEEO-I and MEEO-II. The highest percent hen day egg production was recorded in MEEO-I compared to MEEO-II and control diets. The mean feed intake and feed efficiency /dozen eggs were significantly (P<0.05) influenced by supplementation of MEEO-I and MEEO-II. The overall feed intake was significantly (P<0.05) lower in MEEO-I (106.54g) and highest in control group (108.27g). The better feed efficiency per dozen eggs was noticed in MEEO-I (1.391) and poor in control group (1.454) during 22-37 weeks of age. Egg weight, egg mass and body weights were not affected by supplementation of MEEO-I and MEEO-II to the diets. Among egg quality parameters Haugh unit, albumen index and shell thickness values were significantly (P<0.05) higher in MEEO-I supplemented group followed by MEEO-II group. Whereas, yolk index, yolk color, eggshell weight, eggshell percentage and shell breaking strength were not influenced by the dietary treatments. The mortality was within the limits during 22-37 weeks of age. Serum total protein concentration was not (P>0.05) affected either by supplementation of MEEO-I and MEEO-II to the diets. Whereas, there was significant (P<0.05) reduction in the serum total cholesterol concentration by supplementing MEEO-I and MEEO-II. The MEEO-I and MEEO-II influenced net profit per dozen eggs which was highest in MEEO-I (Rs.15.66) followed by MEEO-II (Rs.15.11) compared with the control (Rs.14.49) during 22-37 weeks of age. Based on the overall results, it was concluded that supplementation of MEEO-I and MEEO-II both @ 100g/ton of feed has improved the layer production performance, albumen quality, shell thickness, feed cost per egg mass and reduced serum total cholesterol levels.EnglishThesis