UVAS Library

Your cart is empty.

Your search returned 2 results. Subscribe to this search

Not what you expected? Check for suggestions
Unhighlight Highlight
|
1.
No cover image available
Pathogenesis Of Field Isolates Of Mannheimia Hemolytica In Experimentally Infected Rabbits

by Syeda Fakhra Waheed (2014-VA-10) | Prof. Dr. Zafar Iqbal Chaudhry | Prof. Dr. Asim Aslam | Prof. Dr. Aftab Ahmed Anjum.

Material type: book Book; Literary form: not fiction Publisher: 2016Dissertation note: Shipping fever is one of the most economically important infectious diseases of ruminants with a wide prevalence throughout the continents. The disease is characterized by an acute febrile course with severe fibrinous bronchopneumonia. Infected animals may die within a few days of the onset of clinical signs, but those which survive the acute attack may become chronically infected. Both Mannheimia and Pasteurella species are commensally resident in the respiratory tract of healthy ruminants and are capable of causing infection in animals with compromised pulmonary defense system. Bovine respiratory disease (BRD) is the most common and costly problem encountered in stocker or feedlot calves. BRD also called “shipping fever”, accounts for major economic losses to the producer by reducing average daily gain, feed efficiency, and overall performance of beef calves. The aim of present study was isolation of M.haemolytica from cattle. The identification of organism was performed through biochemical tests and confirmation by polymerase chain reaction. The nature of disease was evaluated through gross and microscopic lesions. A total of 50 tissue samples (25 lungs and 25 pharynx) were collected from Punjab Agriculture and Meat company Lahore and brought to the Department of Pathology UVAS, Lahore and were analyzed for biochemical and molecular detection of M .haemolytica. For studying the pathogenesis of the disease, experimental infection was given to rabbits in Department of Pathology, UVAS Lahore. Rabbits were randomly divided into Group A, Group B and Group C with nine rabbits (n=9) in each group. Experimental infection of field isolated M. hemolytica was given intratrachealy to the rabbits. Rabbits of group A and B were infected with 0.5 mL bacterial inoculum having 103 and 106 CFU/mL respectively. The rabbits of Group C served as control group. Rectal temperature of each rabbit was recorded daily. On postmortem, CHAPTER 6 SUMMARY Summary 67 gross and microscopic lesions were recorded. The results showed that rabbits of control group not showed any gross or microscopic change. There was significant increase in rectal temperature of infected rabbits as compared to uninfected rabbits. The gross lesions were specific for the organism which was prominently observed in lungs of rabbits. The microscopic lesions revealed that there was severe consolidation, congestion and fibrin exudation in lungs of rabbits of group A which were given less number of organism and they developed clear signs of disease. The rabbits of Group B showed less prominent signs compared to group A due to early death of rabbits. There were multiple hemorrhages, of varying sizes and hyalinization of myocardial cells in infected rabbits. The severity of changes was significantly more different in Group A, as compared to Group B. It can be deduced by this study that the rabbit can be used as a model for further studies exploring the pathogenesis of the disease as the lesions resemble to shipping fever caused by M. hemolytica in ruminants. The lesions, which developed, could be descending infection resulting in typical lesions of bronchopneumonia or lobular pneumonia. Availability: Items available for loan: UVAS Library [Call number: 2517-T] (1).

Place hold Add to cart
2.
No cover image available
Pathogenesis Of Aflatoxin B1 In Quails Under Experimental Conditions And Detoxification By Biological And Chemical Means

by Sakhra Mahmood (2005-VA-251) | Prof. Dr. Muhammad Younus Rana | Prof. Dr. Asim Aslam | Prof. Dr. Aftab Ahmed Anjum.

Material type: book Book; Literary form: not fiction Publisher: 2016Dissertation note: Secondary metabolites of certain fungi produce toxins under favorable conditions especially while growing on different food grains. Mycotoxins are among major threats to growing poultry industry and human beings. Aflatoxins are closely related, biologically active fungal metabolites and commonly produced by Aspergillus species. A research was carried out to evaluate the ability of Aspergillus flavus for Aflatoxin B1 production using rice, wheat and maize as substrates. Lethal effects on growth performance parameters, hematological and histopathological of graded doses of aflatoxin B1 in quails under experimental conditions were observed. Effect of Aflatoxin B1 on humoral immune response to Newcastle Disease virus vaccine in quails were determined. Biological detoxification of Aflatoxin B1 by Saccharomyces servisiae was evaluated in quails. Comparative evaluations of different commercially available toxin binders were checked. All these experiments were carried out till the six weeks (42 days). Aspergillus flavus was identified on the basis of macroscopic and microscopic characteristics. Rice, wheat and maize grains was used as substrate to check the level of Aflatoxin B1 produced by inoculating an aqueous suspension of 106 spores/ml. Aflatoxin B1 checked by Thin Layer Chromatography (TLC) and quantified by High Performance Liquid Chromatography (HPLC). Quails were reared under standard management conditions in five groups (A, B, C, D and E) having sixty each. Each group was further divided in two independent units. Diets offered to groups were control (without toxins), 0.25, 0.50, 1 and 2 mg Aflatoxin B1/kg feed. One unit of SUMMARY 187 each group was vaccinated with Newcastle Disease Virus (NDV) vaccine while other was not and studied the lethal effects on growth performance, blood parameters, immune response and histopathology of vital organs. At the end of the experiment, it was found that the deleterious effects of Aflatoxin B1 were dose and duration dependent. As the level of the toxin was increased, the lethal effects were prominent. The growth performance parameters including gain in body weight, feed intake and feed conversion ratio was adversely affected at high doses. The body weight gain was significantly reduced in Aflatoxin B1 treated groups as compared to control group. Similarly feed intake and feed conversion ratio were significantly different from the control group. The hematological studies exhibited that aflatoxin B1 significantly reduced the hemoglobin, packed cell volume and total leukocyte count whereas the erythrocyte sedimentation rate was significantly increased as compared to control group. The immune response against NDV vaccine was adversely effected in Aflatoxin B1 treated groups and values of Antibody titer in AFB1 were significantly low as compared to group A( control) In the second experiment, Saccharomyces cervisae (SC) dried powder was mixed in basal quail diet having 0.5mg Aflatoxin B1 for all experimental groups and control was without toxins. SC was added at levels of 0.5 gm, 1.0 gm and 2.0 gm /kg of feed. It was recorded that Saccharomyces cervisae (yeast) have the potential to remove the deleterious effects of Aflatoxin B1. Yeast effectively detoxified the Aflatoxin B1. The results recorded of growth performance and other parameters were non-significantly different from the control group. Chemical detoxification of Aflatoxin B1 was evaluated in quails using commercially available toxin binders. Toxin binders used were activated charcoal, kaoline, Myco AD and selenium plus vitamin E and mixed in basal quail diet having 0.5mg Aflatoxin B1 for all experimental groups and control was without toxins. The Myco AD and selenium plus vitamin E showed the highest detoxification potential as compared SUMMARY 188 to other chemical toxin binders. Groups E and F showed the results of growth performance, hematological, immune response and histopathological were non-significantly different from the control group (A). Kaolin was moderately detoxifying the toxin. Presence of aflatoxin B1 in soft tissues was checked by TLC and quantified using HPLC. The liver exhibited the residues of Aflatoxin B1 at high doses of toxin. Group D and E rearing on feeds having 1mg AFB1 /Kg feed and 2mg AFB1 /Kg feed of toxin showed the residues of AFB1 in liver and kidney. Statistical means for growth performance parameters, hematological, immune response and histopathological scores in each subunit of quails were analyzed by applying one way ANOVA and Duncans‟s Multiple Range (DMR) test at 95% probability. Aflatoxin B1 is lethal and lowers the performance of birds. The lethal effects can be detoxified by biological and chemical means to lower the economic losses to poultry industry. It can be concluded that biological detoxification is preferably better as compared to chemical detoxification. Availability: Items available for loan: UVAS Library [Call number: 2670-T] (1).

Place hold Add to cart

Implemented and Maintained by UVAS Library.
For any Suggestions/Query Contact to library or Email:rehana.kousar@uvas.edu.pk Phone:+91 99239068
Website/OPAC best viewed in Mozilla Browser in 1366X768 Resolution.