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Bayesian Statistics: Concepts and Applications in Animal Breeding – A Review
2011
Lsxmikant-Sambhaji Kokate | G.R. Gowane | Dige M.S. | Sonawane G.S. | C Mishra | R.K. Singh
Statistics uses two major approaches- conventional (or frequentist) and Bayesian approach. Bayesian approach provides a complete paradigm for both statistical inference and decision making under uncertainty. Bayesian methods solve many of the difficulties faced by conventional statistical methods, and extend the applicability of statistical methods. It exploits the use of probabilistic models to formulate scientific problems. To use Bayesian statistics, there is computational difficulty and secondly, Bayesian methods require specifying prior probability distributions. Markov Chain Monte-Carlo (MCMC) methods were applied to overcome the computational difficulty, and interest in Bayesian methods was renewed. In Bayesian statistics, Bayesian structural equation model (SEM) is used. It provides a powerful and flexible approach for studying quantitative traits for wide spectrum problems and thus it has no operational difficulties, with the exception of some complex cases. In this method, the problems are solved at ease, and the statisticians feel it comfortable with the particular way of expressing the results and employing the software available to analyze a large variety of problems.
显示更多 [+] 显示较少 [-]Studies on pathogenicity of Aeromonas species to native breed (Fayoumi) chickens
2011
Zeinab M. S. Amin Girh | K. M. El-Bayoumi | Eman. R. Hassan | K. M. Mahgoob
The pathogenic effect of representative local isolates of Aeromonas organisms was studied on 1٠0 native breed chickens. At 2 weeks of age, one hundred chicks were grouped into four equal groups (1-4); 25 birds each; after collection of fecal from all groups, examined and proved to be free from Aeromonas species. All groups were subcutaneously (s.c) inoculated with 0.5 ml containing 9×105 cfu /bird. Group 1 of chickens was infected by A. hydrophila; while group 2 was infected with A. caviae. The third group was infected with A. sobria; while, chicks of Group 4 were kept as non infected control. Results were showed mild clinical signs in some birds in theform of alternative diarrhea. Post mortem lesions showed general congestion of all carcasses. In severely emaciated cases the lesions were confined to the intestine, which filled with watery fluid and distended with gas. Results of Aeromonas reisolation revealed that all collected weekly fecal swabs were positive. While, percentage of A. hydrophila and A. caviae was 100% out of all testedorgans, while isolation of A. sobria was 100%, 100% and 80% from liver, intestine and heart; respectively. Histopathological examination of infected chicken organs showing focal coaggulative necrosis in liver with mononuclear cells infiltration that varied in severity between groups as less severe in A. hydrophila (Gr.1) than A. caviae (Gr. 2), while A. sobria (Gr. 3) was markedly affected showing severe degenerated and dissociated hepatocytes. Intestinal changes were severe in group 3 than 2 while group 1 showing the mildest comparatively the changes was consist of necrosed mucosa, gland with leucocytic infiltration in lamina propria. Under thecondition of our study we can conclude that the used Aeromonas isolates from field diseased chickens were of mild pathogenicity to s.c. inoculated 12 days old Fayoumi chicks with long course affection.
显示更多 [+] 显示较少 [-]Trials for isolation of reticuloendotheliosis virus from commercial chicken flocks for using the isolates in the detection of extraneous virus contamination in live vaccines
2011
Badawi A. A. | Salama S. S. | Elham A. Elibiary
In an attempt to isolate reticuloendotheliosis virus (REV) from field cases, plasma ofcommercial broiler chickens-suspect to have virus infection-were examined. Samples were inoculated in chicken embryo fibroblasts and after proper incubation infected cultures were assayed for REV-antigen by ELISA, immuno-peroxidase (IP) plaque assay, and PCR.Specificity of ELISA and IP was evaluated by comparing their results with that obtained by PCR. REV could be isolated and virus antigen was detected in cell cultures by all three techniques. Results showed that PCR and ELISA are more specific than IP in detection of REV-antigen. However, the sensitivity of ELISA was affected by the criterion used for determination of the cut-off point. Further studies are needed for full characterization of the isolated virus by using reference antiserum or strain specific primers for PCR.
显示更多 [+] 显示较少 [-]Evaluation of the antioxidant protective effect of oxytocin and silymarin against gentamicin-induced nephrotoxicity in rat
2011
Ghada, M. Safwat | Abeer, M. Radi
Gentamicin is an effective aminoglycoside antibiotic against severe infections. In spite of inducing nephrotoxicity and oxidative damage, gentamicin is used clinically due to its wide spectrum of activities against Gram negative bacterial infections. Its nephrotoxicity occurs by selective accumulation in renal proximal convoluting tubules. Its nephrotoxicity involves renal free radical generation and reduction in antioxidant defense mechanisms. A potential therapeutic approach to protect or reverse gentamicin-induced oxidative stressand nephrotoxicity would have more importance for clinical consequences. Therefore, thepresent study was designed to investigate the possible antioxidant protective effects of oxytocin and silymarin against gentamicin-induced renal damage in rats. A total of 40 adult male albino rats were divided into four groups. The first group is the control group that received normal saline (1ml/kg/i.p/day for 8 consecutive days), the second group was treated withgentamicin(80mg/kg/i.p/day for 8 days), the third group was treated with gentamicin (80mg/kg/i.p/day for 8 days) and oxytocin (5 I.U/kg/i.p/day for 8 days) and the fourth group was treated with gentamicin (80mg/kg/i.p/day for 8 days) and salymarin in a dose of (50 mg/kg orally/day for 8 days). Some biochemical and histopathological examinations of kidneys were performed after treatment for evaluation of the oxidative stress and renal nephrotoxicity. Gentamicin treatment significantly increased serum urea and creatinine levels and AST activities. Also gentamicin significantly decreased the total antioxidant capacity and catalase activity in renal tissues. Renal tissue malondialdehyde (MDA) has a non significant increase, while renal reduced glutathione (GSH) wasn't changed. Study of renal morphology showed degenerative changes in the form of cloudy swelling, hydropic degeneration and glomerular necrosis in gentamicin group. Administration of oxytocin and silymarin with gentamicin ameliorated to some degree the biochemical changes and oxidative stress parameters against gentamicin-induced nephrotoxicity. It was concluded that treatments with these antioxidants could have beneficial effects in treatment of gentamicin induced nephrotoxicity.
显示更多 [+] 显示较少 [-]The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part III. The less commonly collected species
2011
Gordon J. Gallivan | Andrea Spickett | Heloise Heyne | Arthur M. Spickett | Ivan G. Horak
Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP). From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4). Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.
显示更多 [+] 显示较少 [-]Paraphimosis in a Great Dane Dog - A Case Report
2011
Asif Iqbal | A.K. Tripathi
A one year old male Great Dane dog weighing around 30 kgs, was presented to the Veterinary Clinics and Teaching Hospital (Faculty of Veterinary Sciences and Animal Husbandry, SKUAST, R.S. Pura –Jammu, India), with paraphimosis of eight-hour duration The penis was engorged and congested and there were several dark haemorrhagic areas. An edematous preputial band was constricting the penis, preventing its retraction in to sheath. After treatment, the inflammatory swelling subsided and animal was recovered uneventfully with no recurrence up to two months of follow-up.
显示更多 [+] 显示较少 [-]On the origin and diversity of Newcastle disease virus in Tanzania
2011
Mmeta G. Yongolo | Henrik Christensen | Kurt Handberg | Uswege Minga | John E. Olsen
Free-range rural chickens (FRCs) dominate the poultry industry in developing countries and chickens are exposed to multi-host infections, including Newcastle disease virus (NDV). The knowledge about the characteristics of NDV from FRCs is limited. This study investigated the persistence, spread and risks of NDV from FRCs. NDV isolates (n = 21) from unvaccinated FRCs in Tanzania were characterised by conventional intracerebral pathogenicity index (ICPI) and sequence analysis of a partial region of the deduced fusion protein encompassing the cleavage site. Results showed that five isolates were screened as lentogenic, nine as mesogenic and six as velogenic. Phylogenetic analysis of the 21 isolates compared to reference sequences revealed three, four, nine and five isolates in genotypes 1, 2, 3c and 4a, respectively. Genotype 3c also included published sequences of Tanzanian isolates obtained from exotic birds and chicken isolates from Uganda. The analysis showed that NDV were persistently present among chicken populations and possibly spread through live chicken markets or migration of wild birds. Differences in amino acid sequences detected around the cleavage site separated the isolates in six types. However, cleavage site pattern could not fully differentiate mesogenic isolates from velogenic isolates.
显示更多 [+] 显示较少 [-]Effect of Tris and Biociphos-Plus Extenders on the Extracellular Enzyme Release of Phosphatases and Transferases in Punganur Bull Semen
2011
K . Veerabramhaiah | A. Seshagiri Rao | V.H. Rao | K. Venugopal Naidu | S.T. Viroji Rao
The present investigation was carried out to study phosphatase and transferase enzymes leakage in the neat and extended Punganur bull semen before and after freezing with Tris and Biociphos-plus extenders. Among the bulls studied, the Alkaline Phosphatase (AKP) concentration in fresh semen was significantly different but Acid Phosphatase (ACP) was not significantly different and a positive correlation between the concentration of AKP and semen volume, individual motility, sperm concentration and total abnormalities were observed. Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) concentrations were not significantly different and positively correlated with individual motility, sperm concentration, percentage of live sperms and acrosomal damage. Leakage of AKP, ACP, AST and ALT enzymes before freezing the semen of Punganur bulls was observed to be significantly higher in the semen extended with Biociphos-plus extender.
显示更多 [+] 显示较少 [-]Ticks of four-toed elephant shrews and Southern African hedgehogs
2011
Ivan G. Horak | Shaun Welman | Stacey L. Hallam | Heike Lutermann | Nomakwezi Mzilikazi
Several studies on ticks infesting small mammals, including elephant shrews, have been conducted in South Africa; however, these studies have included only a single four-toed elephant shrew and no hedgehogs. This study thus aimed to identify and quantify the ixodid ticks infesting four-toed elephant shrews and Southern African hedgehogs. Four-toed elephant shrews (Petrodromus tetradactylus) were trapped in dense shrub undergrowth in a nature reserve in north-eastern KwaZulu-Natal. They were separately housed, first in cages and later in glass terraria fitted with wire-mesh bases to allow detached ticks to fall through for collection. Southern African hedgehogs (Atelerix frontalis) were hand caught on a farm in the eastern region of the Northern Cape Province and all visible ticks were collected by means of tweezers while the animals were anaesthetised. The ticks from each animal were preserved separately in 70% ethanol for later identification and counting. The immature stages of five ixodid tick species were collected from the elephant shrews, of which Rhipicephalus muehlensi was the most common. It has not been recorded previously on any species of elephant shrew. Three ixodid tick species were collected from the hedgehogs. Large numbers of adult Haemaphysalis colesbergensis, which has not been encountered previously on hedgehogs, were collected from these animals. Four-toed elephant shrews are good hosts of the larvae and nymphs of R. muehlensi, and Southern African hedgehogs are good hosts of adult H. colesbergensis.
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