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اجازة نتيجة الطالبة رزان كمال الدين نصرالدين عبدالله ماجستير العلوم في بنيئة الشبكات كلية الدراسات العليا
No full textاجازة نتيجة الطالبة رزان كمال الدين نصرالدين عبدالله ماجستير العلوم في بنيئة الشبكات كلية الدراسات العلي
Enzymatic Study on the Microbial Degradation of Homocholine
No full textThis research was conducted to investigate the enzymatic activities in the
degradation pathway of homocholine by bacterial strains isolated from the soil. Screening
of the homocholine oxidation activity in the isolated strains, by replica staining method
and spectrophotometric assay, showed that NAD+ - dependent dehydrogenase enzymes
were predominant in all isolates. Furthermore, dried cell reaction of Pseudomonas sp.
strain A9 cells with homocholine in the presence and absence of NAD+ demonstrated that
the enzymes responsible for the metabolism of homocholine were alcohol and aldehyde
dehydrogenases that require NAD+ as electron acceptor. Moreover, in the cell free extract
of Pseudomonas sp. strain A9 an inducible NAD+ - dependent homocholine
dehydrogenase was detected. The crude preparation of this enzyme has broad substrate
specificity. Although various buffering conditions and stabilizing reagent were applied to
stabilize the enzyme activity, the enzyme was unstable in vitro and lost its activity soon
after and during the purification processes. Furthermore, an inducible NAD+ - dependent
3- hydroxypropionate dehydrogenase activity was also detected in the cell free extract of
Pseudomonas sp. strain A9. This result indicated the presence of 3-hydroxypropionate as
an intermediate metabolite in the degradation pathway of homocholine by this strain.
Thus, in Pseudomonas sp. strain A9, homocholine is oxidized to
trimethylaminopropionaldehyde by a NAD+-dependent homocholine dehydrogenase and
consequently, trimethylaminopropionaldehyde oxidized to β-alanine betaine by a NAD+ -
dependent aldehyde dehydrogenase. Thereafter, cleavage of β-alanine betaine C-N bond
yielded trimethylamine and 3-hydroxypropionate (C-3 moiety). Thereafter, 3-
hydroxypropionate was further oxidized to malonate semi-aldehyde by a NAD+ -
dependent 3-hydroxypropionate dehydrogenase
Testing of a Detection Protocol for Genetically Modified Food Probably Found in Sudanese Markets
No full textIn recent years, genetically modified foods (GMFs) found their way to the
international food markets, particularly those of under-developed countries. The safety of
the GMF is a controversial issue, even in the scientific community, and great concern was
raised by consumers and legislators. The consumers had the right to know whether their
food or some of it is genetically modified. The aim of this study was to develop and test a
protocol to detect GMFs in the Sudanese food markets. The study targeted soybean
(seeds and isolated proteins) and cotton seeds as both could be used directly or indirectly
in human foods. The collected samples were examined for the presence of 35s promoter
and NOS terminator using a DNA/based - polymerase chain reaction (PCR) and real
time PCR. DNA was extracted from the samples and its purity and concentration were
determined. Mineral content was determined with inductively coupled plasma with mass
spectrometry (ICP-MS) and the fatty acid profile with GC. In addition, the peroxide value
(PV) and proximate composition of the samples were also determined. The results
showed that the DNA of all samples under investigation had concentrations in the range
of 500 -1500 ng/ul and a purity of 66%-89%. Real time PCR showed that cotton seed
cake samples were + ve for TNOS and 35s primers, while isolated soy protein sample
was + ve only for 35s primer and -ve for TNOS. Soybean seeds and isolated soybean
protein were all -ve for both primers and as such not genetically modified. The chemical
and biochemical analysis of GMFs and non GMFs showed some differences that cannot
be attributed to the genetic modification alone at this juncture. It is concluded that the
protocol used is an effective one, and the real time PCR is a sensitive technique for the
detection of genetically modified foods, yet further studies by accredited laboratories are
strongly recommended
Effect of Dietary Inclusion of Gum Arabic (Acacia senegal) on Performance and Blood Chemistry of Broiler Chicks
No full textThe aim of this study was to evaluate the effect of feeding graded levels of gum Arabic
on the performance of broiler chicks and on blood chemistry. A total of 192 unsexed
broiler chicks (Cobb strain) were randomly assigned to four dietary treatments (0, 2.5, 5
and 7.5% gum Arabic), each treatment was composed of six replicates (8 birds/
replicate). Feed and water were offered ad libitum throughout the 42-days experimental
period. Growth performance parameters and blood parameters (albumin, glucose,
phosphorus, calcium, total protein, cholesterol, creatinine and triglyceride) were
determined. Feed intake, body weight gain and feed conversion ratio were not influenced
by the dietary inclusion of gum Arabic. The different levels of gum Arabic had no effect
on blood serum constituents, except total protein which increased significantly.
Cholesterol, creatinine and triglyceride levels were decreased significantly in birds fed
5% and 7.5% gum Arabic. It is concluded that the incorporation of gum Arabic in broiler
chickens diets has positive effects on broiler chicks' performance and reduced serum
levels of cholesterol levels, creatinine and triglyceride
Effect of Postmortem Aging Period on Quality Properties of Bovine Muscles, Longissimus dorsi, Semimembranosus and Semitendinosus, Held at 2ºC
No full textA study was conducted to investigate the effect of postmortem aging period (1, 5, 10, and
15 days) on meat quality of bovine muscles, Longissimus dorsi, Semimembranosus and
Semitendinosus, held at 2°C. Fourteen western Baggara bulls were used. The
hindquarters were immediately chilled at 2°C for 24 hours, L. dorsi, Semimembranosus
and Semitendinosus were cold deboned, each one was divided into four parts and aged
immediately after deboning for 1, 5, 10 and 15 days at 2°C. Temperature and pH profile,
chemical composition, bacterial load and muscle eating quality were determined. The
extractable myofibrillar proteins, the non-protein nitrogen and the water holding capacity
were significantly (P≤0.001) increased, while the extractabe sarcoplasmic proteins
significantly (P≤0.001) decreased; cooking loss and colour rating scores decreased and
tenderness increased numerically with increasing aging period to 15 days. Increasing
aging period from 5 to 15 days resulted in low flavour rating and increasd juiciness but
non-significantly for the three muscles studied. SDS polyacrylamide gel electrophoresis
revealed a gradual decrease and disappearance of the troponin-T and a built up of a 30 kd
component seems to be the major changes during postmortem aging. Complete
disappearance of toponin-T and appearance of a 30 kd component at day 10 of aging and
continue to be observed at day 15
Prediction of Digestibility and Intake of Roughage Diets Fed to Ruminants
No full textPredicting intake of roughage diets by ruminants uses simulation modelling. This study
takes advantage of studies (e.g. Illus and Gordon 1991) that generalize across ruminants.
The aim was to test the suitability of Illius and Gordon’s model, and modify it for
predicting digestibility and intake of roughages in tropical ruminants. Data from seven
studies on roughages fed to tropical ruminants were used. These studies had 235 intake
and 70 digestibility measurements on diets of cattle (n=43), goats (n=5), and sheep (n=
22), with at least 5 animals.diet-1. Animals in all degradation studies, but one (study 2),
were provided with protein supplement; roughages were fed non-supplemented except in
one (study 3). The model comprises 13 digesta pools in the rumen and six post-ruminal
pools. Fluxes among pools were modelled by a system of ordinary differential equations.
Ingesta were partitioned into long and short particles, chemically into cell content (CC)
and cell wall (CW), and biologically into digestible CW (DNDF) and indigestible CW
(INDF). Once consumed, the CC in the fine particle pool is instantly digested; other
particles are retained in the rumen for the duration of the lag phase. All solid matter in the
rumen contributed to the level of fill. Maximum rumen load was determined as a
function of body weight. Ingesta disappeared from the rumen at a rate determined by
fractional rates (FR) of degradation (kdig or k2) and passage of particles (kp) for short and
long particles. The model allows a maximum of eight meals/ day. A re-run of the model
was needed after re-calibration: kp (/h) = 0.0907 x NDF-0.373 x kdig
0.40 (n=72; R2=0.37);
and rumen DM load (RL) as a function of live weight (W) in proportion to the mature
live weight (MW): RL (g/kg W) = e3.38*(W/MW)-0.27*CP-0.17 (n=26, R2=0.31), with CP in
g.kg-1. Observed vs predicted digestibility and intake were respectively 0.52±0.080 vs
0.53±0.132 and 60±0.10.5 vs 59±0.12.9 for sheep, 0.69±0.057 vs 0.61±0.101 and 69±8.3
vs 63±20.8 for goats; and 0.59±0.097 vs 0.56±0.080 and 79±0.15.6 vs 66±0.12.0 for
cattle. Relationships between observed and predicted digestibility (R2=0.17) and intake
(R2=0.13) were poor. A re-run of the model increased the variation accounting for
digestibility (R2=0.32) and intake (R2=0.49); showing two studies (R2=0.66-0.83 for
intake; or 0.78-0.85 for digestibility) with good precision. Both rates of passage and
digestion are largely properties of feeds, but rumen load is affected by animal and plant
factors. Modified particulate rate of passage and rumen load increased predictions
substantially. Consequently, more research is required to in this area to refine these
parameters
الواقع والرؤى المستقبلية لصناعة الدواجن فى السودان
No full textتشهد صناعة الدواجن فى السودان نمواً مضطرداً على جميع الأصعده أفقياً وراسياً خاصة فى العشر سنوات الأخيره . وتظهر الإحصائيات هذا التطور السريع المتنامى فى مزارع أمات اللاحم والبياض والدجاج اللاحم والبياض والمفرخات ومصانع الأعلاف والمجازر فى شركات الدواجن القائمة ومشاريع الدواجن الجديدة . حيث تستخدم التقنيات الحديثة ونسبة لإرتفاع أسعار منتجات اللحوم الحمراء فى السنوات القليلة الماضية . تحول المواطن السودانى إلى إستهلاك لحوم الدواجن نسبة لإرتفاع قيمتها الغذائية وإنخفاض أسعارها حيث سعر كيلو اللحوم 2-3 أضعاف سعر كيلو الفراخ وعليه تضاعف إنتاج لحوم الدواجن إلى أكثر من 2–3 أضعاف حيث إرتفع الإنتاج من 25-30 ألف طن إلى أكثر من 100 ألف طن فى العام 2013م علماً بأن الفرد السودانى يستهلك 2–3 كيلو/ العام . مقارنة بـ 9.2 كيلو/ العام لمتسوط الفرد فى العالم . ولحوم الدواجن تشكل أحد مرتكزات الأمن الغذائى فى البروتين الحيوانى . وتم إستيراد 500 ألف كتكوت أمات لاحم و 70 ألف أمات بياض و12 مليون بيضة تفريخ لاحم ومرتكزات ومضافات علفية فى العام 2012 بلغت قيمتها 475 مليون دولار . هذا وأن إنتاج اللحوم البيضاء يقلل من المسحوب السنوى من اللحوم الحمراء للإستهلاك المحلى مما يوفر فائض للتصدير ليعود بالعملات الحرة . وكما هو معلوم فإن صناعة أعلاف الدواجن لها تأثير مباشر على إقتصاديات الإنتاج حيث أنها تمثل 60%-70% من تكلفة الإنتاج علماً بأن السودان يعتمد على الذرة الفتريتة فى تصنيع الأعلاف مختلفاً عن كل الدول التى يعتمد على الذرة الشامية فى تغذية الدواجن والذى بدأت أسعارها فى الإرتفاع فى السنوات الخمس الماضية نسبة للمنافسة فى إستخدامه فى إنتاج الطاقة الحيوية – الأيثانول . وقد أثبتت التجربة العلمية والبحوث الجارية فى مراكز البحوث والجامعات بأنه يمكن الإعتماد على الذرة الفتريتة فى تغذية الدواجن ليس فى السودان فحسب بل للدول العربية المستقب
Desertification in China: Current Status, Cause, and Solutions
No full textChina is one of many countries that suffer from desertification. Given the large
scale of the problem and insufficient national funding, combating desertification remains
an arduous task. Even with a long-standing governmental commitment and numerous
successful model projects, land desertification in China has become worse and turned
into a major impediment to the economic development in desertified regions. In China,
the most serious problem of desertification is to be found in the agro-pastoral transitional
zone in northern China and in the oases along inland rivers or in the lower reaches of
inland rivers in northwestern China’s arid zone. There are three root causes leading to
desertification in China: vulnerable eco-environment, high population pressure, and
backward techniques and extensive management. Based on the analysis of the causes of
desertification, the author suggests that in China the close combination of prevention,
rehabilitation, and exploitation are the basic principle for bringing desertification under
effective control and realizing sustainable development of society, economy, and
environment over all desertified regions
Impact of Land Use System of Some Land Degradation Indicators in Atbara, River Nile State
No full textThis study was conducted in Atbara Food Security Scheme, River Nile State (lat
16°-22° N and long 32°-36°E), to assess the impact of adopted management systems:
crop rotation, irrigation methods, addition of fertilizers, fodder and trees species, on land
degradation using some biophysical, climate, physical, chemical and biological indicators
of soil properties, species of vegetation cover, salinity, sodality and land productivity.
Forty-five soil samples were collected from three farms of different systems and an
uncultivated site (control). Also, water samples were taken from the main irrigation canal
coming from the River Nile and well used for drinking. Statistical analysis revealed
significant (P≤0.05) differences in some of the soil properties. The results showed that
adopted land use systems have a positive impact on land quality by increasing the organic
mater content and reducing sand content in the cultivated area as compared with the
uncultivated site. The study showed the high suitability of the canal water for irrigation
(ECe = 0.157 dS/m, pH, = 8.03). The characteristic of the drinking water in the study area
fell within the recommended level of WHO (RSC=1.20)