Ph.D. THESIS

I. M. Abaza (2001) Ph.D. Thesis, Faculty of Agriculture, Alexandria University, Egypt.

    The present study was carried out at the poultry research center, Faculty of Agriculture, Alexandria University, throughout the period from 2000 to 2001. Two biological experiments were conducted to determine the effect of adding some dried medicinal plants, either individually or in combination, as a natural growth promoters versus some antibiotics in broiler diets. Six medicinal plants and two antibiotics were used through the experimental period as a growth promoter. These test materials are: Black seed N.S (Nigella Sativa L.), Chamomile flower heads CH.F (Matricaria Chamomila L.), Marjoram leaves M.L (Marjoram Hortemsis L.),  Coriander seeds C.S (coriandrum Sativum), Thyme flowers TH.F (Thymus Vulgaris), Harmala Seeds H.S (Peganum Harmala), Zinc Bacteracian and Virginamycin.

First experiment: One hundred and ninety Hubbard-broiler chicks at three weeks of age were wing - banded, weighed and randomly distributed into nineteen treatments with two replicates (5 chicks of each). Nineteen experimental diets were fed to broiler chicks during the experimental period (3-7 weeks of age). The first experimental diet was as a control diet, while, the eighteen experimental diets were formulated by adding the six medicinal plants at levels 2.5, 5.0 and 10.0 kg / ton of diet individually. The main results and conclusion of the 1^st experiment are shown in the following points:  Insignificant differences among treatments were found for body weight and body weight gain at      the end of the experimental period (7 weeks of age). There were highly significant differences between treatments for feed intake and feed conversion at    the end of the experimental period. The best feed conversion were recorded with the chicks fed diet included 2.5 kg CH.F / ton , 5.0 kg TH.F / ton, 2.5 kg H.S / ton, 10 kg N.S. /ton and 2.5 kg N.S /ton ,respectively. The percentage of viability not affected through the experimental period and there were any mortality recorded during the experimental period. The best four relative economical efficiency (R E E) were recorded by the chicks fed 2.5 kg CH.F, 5 kg TH.F, 2.5 kg H.S and 2.5 kg N.S. / ton of diet, respectively. Generally, it could be recommended that 2.5 kg N.S, 5 kg TH.F, 2.5 kg H.S and 2.5 kg CH.F / ton  of diet could be used individually as economical growth promoters.

Second experiment:This experiment was designed to study the effect of adding the best four medicinal plants at the corresponding best level, which resulted from the first experiment, either individually or in combination versus using Zinc Bactiracin or Virginamycin as growth promoters in broiler diets. The main results and conclusion at the end of experimental period (7 weeks of age) are shown in the following points: The addition of either Zinc Bactiracin or Virginamycin in broiler diets at level (1 kg / ton of diet) had insignificant differences on body weight and body weight gain compared with control group. The addition of the best four medicinal plants individually in broiler diets had insignificant effect on body weight and gain compared with control group. The combination between two medicinal plants in broiler diets indicated highly significant differences among them and compared with control group. The combination between 2.5 kg CH.F + 2.5 kg N.S / ton of broiler diets had the best synergetic effect on body weight and gain. The combination between three of medicinal plants indicated insignificant differences among treatments and also when compared with control group. There were significant differences among treatments of feed consumption. The highest feed intake were noted for the broiler fed 2.5 kg CH.F + 2.5 kg N.S. / ton of diet. There were highly significant differences among treatments of feed conversion. The chicks fed 2.5 kg CH.F + 2.5 kg N.S. / ton of diet had the best feed conversion than all treatments. There were highly significant differences among treatments for digestibility values. The combination between two or three of medicinal plants had the best digestible values of different nutrients. The percentage of viability was not affected. There were insignificant differences among treatments for carcass, abdominal fat, heart, liver, spleen, pancreas, gizzard, bursa of fabricius weight and total intestinal length. There were highly significant differences among treatments for ceccum length. There were significant differences among treatments for total protein, albumin, globulin and total cholesterol in blood serum of broiler chicks. The lowest total cholesterol value was observed for the chicks fed 2.5 kg CH.F + 2.5 kg H.S and 5 kg TH.F  + 2.5 kg CH.F / ton of diet, while, the highest value recorded for the chicks on control group. There were highly significant differences among treatments for broiler color meat. The lowest value recorded for the chicks fed 2.5 kg CH.F / ton of diet. There were insignificant differences among treatments for flavor and consistency of broiler meat. The diets containing 2.5 kg CH.F + 2.5 kg N.S, , 2.5 kg CH.F + 2.5 kg H.S and 5.0 kg TH.F + 2.5 kg H.S / ton of diet had the best relative economical efficiency.

In Conclusion:The results of the present study indicated that: Many of Medicinal plants can used as a natural growth promoters. The using of Medicinal plants (N.S, TH.F, H.S. and CH.F)  either individually or in combination had the best effect than using antibiotics (Zn B or VIR). The using of 2.5 kg CH.F + 2.5 kg N.S. / ton of diet had the best synergetic effect and was more economically than either the other treatments or control.

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