EFFECTS OF DIFFERENT LEVELS OF BLACK CUMIN SEEDS (Nigella sativa L.) AS AN ADDITIVE ON LAYERS PERFORMANCE AND BLOOD BIOCHEMICAL CONSTITUENTS

The study was conducted to investigate the effects of different levels of black cumin seed (Nigella sativa L.) on chicken performances, fertility and hatchability of egg, chick quality, embryonic mortality, blood parameters and economic benefit of black cumin seeds on white leghorn layers at Haramaya University Poultry Farm for 70 days. One hundred eighty WL layer at twenty- four weeks of age with an average initial body weight of 1219.52± 5.45g were randomly distributed to four treatments, each replicated three times with fifteen layers and two cockerels per replications in CRD and kept on a deep litter system. The treatment rations were formulated by supplementation of BCS on 100kg layer diet with the proportion of 0kg per 100kg LR (T1), 1 kg per 100 kg of LR (T2), 2 kg per 100 kg of LR (T3) and 3 kg per 100 kg of LR (T4). Chicken were offered a weighed amount of feed and orts were collected and weighed the next morning. Weight of experimental birds was taken at the beginning and at the end of the experiment. The samples of feed additive and layer diet were analyzed for chemical composition before start of experiment. Data were subjected to analysis of variance for all parameters considered. Partial budget analysis was undertaken to evaluate the economic benefits of the different levels of black cumin seeds. Daily feed intake of chickens fed diet consisting of T1 (101.89±0.66g) and T2 (98.36±0.66g) was significantly (P < 0.01) higher than T3 (97.26 ± 0.66g) and T4 (96.07±0.66g). There were no significant differences (P > 0.05) among treatments in daily body weight gain, egg weight, albumen weight, yolk diameter, Haugh unit, fertility, hatchability, embryonic mortality, chick length, chick visual score and total WBC count. Chickens on T3 had higher hen-day egg production (54.85%) compared to chickens on the control ration (45.68%). The egg mass from chicken on T3 (26.32g) was significantly (P < 0.01) higher than that of the chickens on T4 (24.71 g), T2 (23.93g) and the control diet (22.43g). The feed conversion ratio differs significantly (P < 0.01) between treatments from 4.54% to 3.70%. The best feed conversion ratio (3.70%) was obtained when diets were supplemented with 2kg black cumin. The egg yolk color score increased by the addition of BCS in laying hen diets compared with control. Egg from laying hens fed a diet supplemented with BCS had significantly (P