Prof. Berhan Tamir, Dr. Etalem TesfayeYonatan, Kassu2018-11-292023-11-082018-11-292023-11-082018-04http://etd.aau.edu.et/handle/123456789/14690PhD ThesisTwo experiments were conducted to examine the growth and health promoting efficiency of black cumin and fenugreek seeds and turmeric rhizome. The aim of phase I experiment was to determing the optimum dosage levels of seeds of black cumin and fenugreek and rhizome of turmeric as phytobiotic feed additives. The phase II experiment was aimed at the synergistic effects of the different blends of phytobiotic feed additives against commercial antibiotics (Oxcytetracyclin). For the first experiment (phase I), six treatments containing black cumin, fenugreek and turmeric at the levels of 1 and 2% each of the total diets and a control diet were used. In phase II, six experimental diets containing negative control basal diet (T0), positive control basal diet + oxytetracycline at 0.035% (T1), basal diet + a blend of black cumin seed and fenugreek (T2), basal diet + a blend of black cumin seed and turmeric powder (T3), basal diet + a blend of fenugreek seed and turmeric powder (T4) and basal diet + a blend of black cumin seed + fenugreek seed + turmeric powder (T5) at equal proportion were used. A total of 315 and 270 (Cobb 500) a day-old broiler chicks were randomly allocated to 7 and 6 treatment combinations for experiment I and II, respectively with 3 replications per treatment. Chemical analysis of the feeds used, feed consumption, weight gain, carcass characteristics, hematological parameters, serum biochemistry profile, immune response, ceacum microbial load and economic viability were measured. The results of Phase I indicated that; turmeric and black cumin at both levels ensured high feed conversion ratio (FCR) (P≤0.05) than the control birds. However, there were no significant differences (P≥0.05) in BW, BW gain and ADG among treatments. There were significant differences (P≤0.05) in commercial carcass and edible carcass yield among the treatments. Furthermore, turmeric at 2%, black cumin and fenugreek seeds at 1% had significant (P≤0.05) positive effects on Hb and RBC of broilers. Birds fed turmeric and fenugreek at both levels in the diets had reduced serum glucose level (P≤0.05). While, birds fed turmeric at 2%, black cumin at 1% and fenugreek at both levels showed lower serum cholesterol levels (P≤0.05) in broilers. The immunomodulatory response against Newcastle disease (NCD) antibody titer was improved and more pronounced (P≤0.05) in birds fed turmeric powder and fenugreek seed at 2%. Antibody response increased against infectious bursa disease (IBD) in birds fed turmeric powder at 2% and black cumin at 1% than the control birds during the 21st day of age. Higher net return was obtained from birds fed turmeric at both levels and black cumin at 1%. The result of Phase II revealed that there were no significant differences (P≥0.05) in BW gain and ADG between T5 and antibiotics fed birds without negative impact on carcass components and do not have toxin to impair the development of the internal organs (P≥0.05). Lowest feed consumption (T2, T3, T4 and T5) and improved FCR obtained from birds fed different blends of phytobiotic additives treatments (T3 and T5) than the controls T0 and T1 (P≤0.05). The PCV, RBC, MCV and MCHC values were significantly different (P≤0.05) between treatments. Birds fed in T5, T4 and T3 test diets had showed enhanced (P≤0.05) hypoglycemic and hypocholesterolemic effects than the birds in T1 and T0 diets. The mixture of phytobiotic additives (T2, T4 and T5) were superior than the antibiotics in lowering total coliform and E. coli bacteria of the cecum (P≤0.05). Generally, turmeric at 1-2% and black cumin at 1% can be used for profitable broiler production without negative effects on biological performances of birds. Blends of the three medicinal plants can substitute commercial antibiotics and impart positive effects on growth and health performances of broilers.enBlack cuminBiochemicalCarcass characteristicsThesis