Fachbereich Veterinärmedizin



    Detection of genetically modified soybeans and maize in Egypt as well as comparative nutritional safety investigations of isogenic and transgenic (Bt) maize in broiler nutrition, broiler performance, degradation and metabolic fate of maize DNA in some tis (2004)

    Tony, Ahmed Marzok Mohamed Ahmed
    Berlin: Mensch und Buch Verl, 2004 — 137 Seiten
    ISBN: 3-89820-668-8
    URL (Volltext): http://www.diss.fu-berlin.de/diss/receive/FUDISS_thesis_000000001225
    Institut für Geflügelkrankheiten

    Königsweg 63
    14163 Berlin
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    Abstract / Zusammenfassung

    Detection and monitoring of GM soybeans and maize in Egypt As a consequence of rapid progress in agricultural biotechnology, increasing amounts of genetically modified (GM) crops have entered the food and feed chain in recent years. The first aim of the present study, which was conducted during 2000 � 2001, was to monitor the incidence of Roundup Ready soybean (RRS) and the GM maize lines Bt176, Bt11, T25, MON810 and StarLinkTM in Egypt. With the exception of StarLink, which was approved only for feed use, the other constructs were approved for use as food and/or feed in the US and other countries. Fifty-one soybean samples and 61 maize samples were randomly collected from different localities in Egypt. The detection techniques applied were based on Polymerase Chain Reaction (PCR). The results of this survey showed that all soybean samples imported from Argentina, and 50% of American soybean samples contained RRS. Of the 20 maize samples imported from USA, 16 contained Bt176, 17 Bt11, 12 MON810, 19 T25 and 9 StarLink. In addition, of the 7 maize samples imported from Argentina, 4 each contained Bt176 and MON810, 5 T25, 6 Bt11 and 2 StarLink. In contrast, all Egyptian local varieties of soybean and maize were non transgenic. Nutritional and safety assessment of Bt-maize in broiler nutrition The further goal of the present work was to investigate the nutritional and safety aspects of a new Bt176 hybrid (NX 6262-Bt176) in broiler nutrition, degradability of maize- DNA in GIT and the metabolic fate of recombinant DNA in broiler�s body as well. The experiment was conducted to determine the impact of feeding of Bt176 maize on general health condition and performance of broiler chickens in comparison with the non-transgenic conventional maize. Maize grains and diets were subjected to proximate analyses. Amino and fatty acids analyses were applied for both maize grains before used in broiler feed to monitor the substantial equivalence of the transgenic maize used. To evaluate the degradation of maize DNA and its metabolic fate in broiler blood, muscles and organs, a feeding experiment with 35 chicks was carried out. One-day-old male broilers were fed ad libitum on either an experimental diet containing 73.6% isogenic or transgenic Bt176 maize grains for 35 days. Maize samples as well as diets were investigated for the proximate chemical composition, amino and fatty acids. All chickens were subjected to nutritional evaluation period at 20th day of age for five successive days, to calculate apparent digestibility organic matter in both diets. At thirty-five days samples were collected at several intervals after feed withdrawal. Prior to slaughter blood samples were collected from all birds by heart puncture to prevent DNA cross contamination. Samples from pectoral and thigh muscles, liver, spleen, kidney, heart muscle, bursa Fabricius and thymus glands were collected. Digesta from different sections of the gastrointestinal tract (GIT) were collected as well. Packed cell volume (PCV) and some serum parameters were investigated. There were no significant differences between control and experimental group concerning chemical composition of feeds, apparent digestibility of organic matter, and all performance parameters measured (P>0.05). Furthermore, there were no differences in the PCV and the analyzed serum parameters between the control and experimental group. Results of the metabolic fate of maize DNA in broiler blood, muscles and organs indicated that only short DNA fragments (199 bp) derived from the plant chloroplast gene could be detected in the blood, skeletal muscles, liver, spleen and kidney, which disappeared after prolongation the fasting time. In heart muscle, bursa of Fabricius and thymus, no plant chloroplast DNA was found. Bt gene specific constructs from Bt176 maize were not detected in any investigated blood or tissue samples.