Veterinary Medicine

Permanent URI for this collection

http://41.63.25.24:4000/handle/123456789/86

Browse

Now showing 1 - 20 of 142

Detection of Biological Effects of Environmental Pollutants of the Kafue River on the Kafue Lechwe (KOBUS LECHE KAFUENESIS)by Characterization of Selected Biomarkers
(2012-01-24) M’kandawire, Ethel
A lot of research in ecotoxicology is currently focused on identifying and developing suitable biomarkers for use in assessing environmental pollution. Thus this study was aimed at assessing the potential of Cytochrome P450 1A1 (CYP 1A1), Cytochrome P450 3A (CYP 3A) and Metallothionein1 (MT 1) as biomarkers in the Kafue lechwe in response to pollutants in the Kafue river. Kafue lechwe liver samples from Lochnivar GMA (n=23) and Blue Lagoon GMA (n=15) were analyzed for the following biomarkers: CYP 1A1, CYP 3A and MT I. Complementary deoxyribonucleic acid (cDNA) was cloned and CYP lAl, CYP 3A and MT 1 partial nucleotide sequences were isolated from liver of Kafue lechwe. The deduced partial nucleotide sequence of lechwe CYP 1A1 revealed higher identities with that of sheep (98%) and cattle (97%). Lechwe CYP 3A revealed higher identities with that of CYP 3A24 of sheep (97%) and CYP 3A4 of cattle (95%). Lechwe MT 1 was closely related to MT of sheep (97%) and MT 1E of cattle (97%). In the phylogenetic analysis, the lechwe CYP 1A1 isoform was located beside sheep and cattle CYP 1A1. The lechwe CYP 3A isoform was located beside sheep CYP 3A24 and cattle CYP 3A4 and lechwe MT 1 isoform was clustered in the same group as that of sheep MT and cattle MT 1E. We then determined the mRNA expression levels of CYP 1A1, CYP 3A and MT 1 as biomarkers of pollution in liver of Kafue lechwe by relative quantitative real time reverse transcription polymerase chain reaction. The study showed that hepatic CYP 1A1, CYP 3A and MT 1 mRNA levels were expressed in all the lechwe samples from both Lochnivar and Blue Lagoon GMAs. However, there was a wide inter-individual variation in the gene expression of all the 3 genes in Kafue lechwe from both sites. Therefore a comparison of the gene expression levels between the two GMAs was determined by normalizing the relative quantities data for Blue Lagoon to one. Single factor ANOVA was employed for the statistical analysis. There was a 6 fold increase in CYP 1A1 mRNA expression in lechwe from Lochnivar GMA compared to lechwe from Blue Lagoon GMA and the difference was significant (P<0.05). There was no significant difference in CYP 3A and MT 1 mRNA expression levels between lechwe from Lochnivar GMA and lechwe from Blue Lagoon GMA (P>0.05). The study therefore demonstrates that hepatic CYP 1A1, CYP 3A and MT 1 mRNA expression levels in Kafue lechwe has the potential to be used as biomarkers of exposure and effect to pollution in the Kafue river.
A study of important cattle ticks and their control at Kayanje ranch on the Chisamba veterinary district at the central Province of Zambia
(2012-08-22) Mimba, Chungu.
Isolation of Bacterial pathogens from dead- in- shell Chicken embryos from local Hatcheries
(2012-08-31) Swithine, Hameenda Kabilika
Commercial hatcheries in Zambia have been experiencing losses due to dead-in-shell embryos for quite sometime. Numerous Salmonella serotypes have been frequently recorded in poultry population in Zambia, but no information is available on bacterial association with dead-in-shell mortality in hatcheries. Hence investigation into three commercial hatcheries of Zambia was made to find out the role of bacterial pathogens in embryonic mortality and hatchability. These hatcheries had an average dead -in-shell losses between 15.2% and 31.1%. One thousand dead-in-shell chicken embryos from each hatchery formed samples. Ten pooled yolk sac contents or whole egg contents formed one sample. The homogenised samples were cultured on suitable media. Isolation and identification of bacteria was done according to standard bacteriological methods. Three hundred and eighty three (383) cultures were isolated. More than half (208) were isolated firom hatchery A, the other two hatcheries B and C had 118 and 57 cultures isolated respectively. Majority of the isolates were enteric group of bacteria. Out of all the isolates Escherichia coli was predominant with 18.28% (70) followed by Staphylococcus species 14.10% (54) and Pseudomonas species 11.75% (45/ Klebsiella species recorded 9.40% (36). Salmonella species, Enterobacter and Citrobacter species recorded 8.87% (34) each. Acinetobacter recorded 6.79% (26), Proteus species had 6.26% (24), Enterococcus species recorded 2.87% (11) and Streptococcus sp. had 1.04% (4). Alcaligenes faecalis and Aeromonas hydrophila both recorded 0.78% (3). Neisseria dentrificans recorded 0.52% (2) and Edwardsiella species., Micrococcus and Providencia recorded 0.26% (1) each. Out of the fifty four (54) Staphylococcus species, forty three (43)were Staphylococcus aureus. Serotyping of Escherichia coli revealed that six (6) cultures were serotype 08:k47, five (5) were serotype 09:k28, two (2) belonged to serotype 032/33:k- and one (1) each were serotype 088:k-, 016:k- and 0101 :k-. Out of seventy cultures of Escherichia coli isolated, fifty four (54) were rough untypable. All these cultures were found to be less or more pathogenic to thirteen (13) day old chicken embryos and white mice. It was also interesting to note that all of the thirty four (34) Salmonella cultures isolated were Salmonella enteritidis. However on phage typing twenty (20) belonged to phage type 4 (PT4), four (4) were phage type 1 (PTl), two (2) were phage type lb (PTlb) and another two (2) were phage type 7(PT7). One was phage type 7a (PT7a) and five were not typed. The isolation of Salmonella enteritidis, especially most invasive phage type 4, in breeding flocks for the first time in Zambia may open a new page in the epidemiology of Salmonella and a need for effective control measures in this country. A few cultures of Escherichia coli, Salmonella enteritidis and Staphylococcus aureus were subjected to antimicrobial senshivity. The results of the antimicrobial sensitivity test showed high levels of antimicrobial resistance. Antimicrobial agents used in the test were Penicillin G, Tetracycline, Gentamycin, Sulphamethoxazole, Furazolidone and Streptomycin. The results showed that Escherichia coli serotypes were resistant to most Antibiotics (52.7%). Most cultures were resistant to Penicillin G followed by Streptomycin and Furazolidone. Antibiotics in Zambia have been used in feeds (especially nitrofurans) as a prophylactic measure to diseases like Salmonellosis and to boost production. The enforcement of legislature regulating the use of antibiotics hasn't been effectively done. This may partly explain the high levels of antimicrobial resistance observed in this limited study. The presence of these highly pathogenic bacteria in dead-in-shell associates them with production losses and are an indication of hatchery hygiene. The significance of these isolates in causing embryonic mortality and lower hatchability is discussed. There was significant correlation between dead-in-shell and hatchability. However direct relationship between bacterial prevalence or contamination and hatchability could not easily be shown. The probable reasons are discussed in this present dissertation.
Utility of immunohistochemical staining technique as a routine tool in Rabies Diagnosis
(2012-08-31) Kalima-Munalula, Mukatimui N
Rabies is one of few diseases that cause anxiety to both the exposed individual and the health authorities responsible for its prevention and control. Diagnostic procedures in rabies have involved histopathological detection of the Negri body, immunofluorescence and mouse inoculation.Brain specimens from suspected and confirmed rabies cases were obtained from the University of Zambia, School of Veterinary Medicine, Lusaka. These specimens were taken from dogs, cats, cows and horses. The specimens were tested for rabies using the Direct Immunofluorescent Antibody Technique (DFAT) and the results compared to those obtained using the indirect avidin-biotin technique using Streptavidin alkaline phosphatase technique and routine haematoxylin eosin (HE) staining for Negri bodies. Fixation in formalin was done for varying lengths of time from 24 to 72 hours. Sections from the paraffin blocks were cut using a sliding microtome at a thickness of 3 micrometers and fished onto clean slides coated with Poly-L-Lysine to avoid detachment during the incubation and rinsing steps. Enzyme digestion using trypsin was applied to sections to unmask antigenic sites concealed during formalin fixation. Fast red TR salt was the chromogen used of the 39 cases tested the DFAT gave positive results in 29 cases and negative results in 10 cases. The immunohistochemical test gave positive results in 25 cases and negative results in 14 cases. The HE staining gave positive results in 16 cases and negative results in 23 cases. Only in one case did the DFAT give a negative result and the immunohistochemical technique give a positive result. Using DFAT as the gold standard, the sensitivity and specificity of the immunohistochemical test and histopathology were calculated. However, these two means of comparison were not sufficient so the level of agreement between the methods was also calculated and a kappa value for each obtained. The sensitivity of the immunohistochemical technique was found to be 82.7%, specificity was 90%. The level of agreement was 85% with a positive predictive value (PPV) of 0.96, and negative predictive value (NPV) of 0.64. The calculated kappa value was 0.64. The histopathological test gave sensitivity of 55.1% and specificity 100%. The level of agreement was 67% with PPV = 1.00, NPV = 0.43. The calculated kappa value was 0.39. It was possible to show that the indirect immunohistochemical technique using Streptavidin alkaline phosphatase can successfully be used to diagnose rabies. This technique is an adjunct to DFAT, and is an alternative in places where it is not possible to keep specimens frozen or to get them to a diagnostic laboratory in a fresh state. Other instances where the immunohistochemical technique can be applied are those where the dark field microscope with an ultraviolet source is not available, or in retrospective studies. It was also shown that trypsin digestion greatly improves the staining quality of the sections. However, digestion beyond 90 minutes was found to result in unacceptable tissue destruction and loss of antigenicity. Thus it was important to establish a time limit for the optimal digestion time. In this work, this was found to be between 30 and 60 minutes using a final concentration of 1 mg/ml in Tris buffer and at an incubation temperature of 37°C. Another aspect that this work attempted to cover was the effect of fixative and fixation time on the results obtained by the immunohistochemical technique. This was done by experimentally infecting mice with rabies virus and the brain collected and fixed in four different fixatives for varying lengths of time. It was possible to obtain positive reaction from tissues fixed in all four fixatives. However, the number of samples obtained was limited because of high number of deaths caused by trauma. Also the mice included in this part of the study were collected at a late time of infection. The virus titres are thus expected to be high. There seemed to be no difference following fixation for different time periods.
Prevalence of trypanosoma Congolense,T. Vivax and T. Brucei infections in Cattle in Petauke district of Zambia
(2012-09-04) Lubinga, Clement
One hundred Trypanosomiasis infected cattle were selected from a sample of 240 cattle located in Petauke district using the haematocrit woo method. This gave an overall trypanosomiasis prevalence of 41.7% in the area. These selected animals were further examined by the stained thin blood smear(TBS), Antigen detecting ELISA(Ag-ELISA) and the Polymerase Chain Reaction(PCR) techniques. The actual infection rates were determined by pooling the resuhs from the respective diagnostic techniques used for each individual animal. The overall Net infection rates were 96% Trypanosoma congolense, 81 % T. vivax and 76% T. b. brucei giving an infection ratio of 1.3:1.1:1 respectively.All the diagnostic techniques used have shown certain limitations in their ability to detect the three trypanosome species. Parasitological methods(Haematocrit and TBS) have shown higher sensitivity for Trypanosoma congolense than for T. vivax and T. brucei giving infection ratios of 29:3:1 by the Haematocrit and 4:2:1 by the TBS for T. congolense, T. vivax and T. brucei species respectively. Although, more mixed infections were detected by the Ag-ELISA and the PCR techniques, their sensitivity for detecting the trypanosome species, especially T. vivax and T. b. brucei was lower than was anticipated. Both Ag-ELISA and the PCR methods gave infection ratios of about 2:1:1 for T congolense, T. vivax and T. brucei respectively.Statistical analysis (ANOVA) of the resuhs showed no significant differences in the established statistical means of the Net infection rates between the three trypanosome species. These results also indicate a high rate of mixed infections of T. congolense, T. vivax and T. b. brucei in cattle suffering from trypanosomiasis in Petauke and the location of sampling(crush pen) did not show any statistical effect on the results.It is clear that the apparent predominance of Trypanosoma congolense reported in Zambia could be a result of the low sensitivity of the routine parasitological methods in use particularly, in detection of T. vivax and T. brucei. A combination of the parasitological examination with Ag- ELISA and/or PCR in the epidemiological surveys of trypanosome species is therefore highly recommended. To improve on the diagnostic performance of the Ag-ELISA and the PCR, it is also recommended that attempts to prepare monoclonal antibodies and primer sets using the local strains should be considered in order to avoid false negative results which may be. originating from some possible regional variations in the trypanosome species.
The Immunogenicity of Irradiated Theileria Parva( Katete) Sporozoites in the Immunisation of Cattle against Malignant Theileriosis
(2012-09-04) Mutoloki, Stephen
The effect of irradiation on the Katete stock of Theileria parva sporozoites either directly (stabilate form) or indirectly (in their tick vectors) was compared to the 'infection and treatment' method of immunisation of cattle against malignant theileriosis. Fifteen steers were randomly divided into five groups using a computerised random number generator. The first group comprising three steers was immunised with T. parva sporozoites harvested from Rhipicephalus appendiculatus ticks and then irradiated at 8.4 krads using the Cobalt source. In the second group, four steers were immunised with T. parva sporozoites irradiated at 20 krads in their R. appendiculatus tick vectors. The third and fourth groups consisting of three steers each were immunised with non-irradiated T. parva sporozoites. In addition, the fourth group was also treated with tetracycline (infection and treatment). The fifth group (control) with two steers was introduced during the challenge of immunised animals and was treated with lethal doses of T. parva stabilates only. The steers in all experimental groups, except the control, resisted lethal challenge with homologous T. parva stabilates. Mild and moderate reactions were observed in the group of steers immunised with stabilates produced from T. parva sporozoites irradiated in their tick vectors (group two) and non-irradiated stabilates only (group three), respectively. Steers in the control group died from East Coast fever. The best results were obtained from the groups of steers immunised with directly irradiated T. parva sporozoites and non-irradiated stabilates with concurrent tetracycline therapy. There was no statistically significant difference(P>0.05) between the infection and treatment method of immunisation and that of directly irradiated stabilates. Estimates of costs showed that farmers would save between $0.39 (calf) and $2.39 (adult) per animal if they used irradiated stabilate instead of tetracycline in the immunisation.
Application of hazard analysis critical control point (HACCP) concept to study cattle slaughterhouse hygiene and Carcass contamination in Zambia
(2012-09-04) Muma, John Bwalya
The Hazard Analysis Critical Control Point (HACCP) concept was applied for the first time to four Zambian cattle slaughterhouses to study slaughterhouse hygiene and bacterial contamination of carcasses. Swabs were collected from carcass surfaces and also from the following environmental surfaces, which were likely to come in contact with carcasses: knives, cutting saws, tables, walls, floors, aprons and worker's hands. Samples were collected from animals at the following operational points: before skinning; after skinning; after evisceration; and after carcasses were chilled for 24 hours. At each operational point, four sites were swabbed except for point A were only two sites were swabbed. Similarly, four different sites were swabbed from each environmental surface per visit. A total of 2176 swabs were collected from 72 carcasses, and 96 swabs from the above mentioned environmental surfaces from slaughterhouses A and B. Observational results for various hygiene categories where scored for slaughterhouse A, B, C and D. Slaughterhouses A and B, in which microbiological contamination analyses were done, had overall mean aerobic plate count, mean total coliform count, and mean coliform count ranges of logio3.67 - 4.14/cm^; logio 1.63 - 2.44/cm^ and logio 1.23 - 1.59/cm^ respectively. Municipal slaughterhouses C and D, with no defined slaughter and dressing procedures, recorded lowest hygiene assessment scores (18.7% and 21.3%) of hygiene satisfaction, respectively). Carcasses that recorded zero duplicate coliform count after skinning were in the range 25 - 30% where as zero duplicates after evisceration ranged from 15-20.3%, Effect of chilling as a critical control point was better illustrated by changes in means of total coliform count (logio 184 to 0.00) and faecal coliform count data (logw 2.5] to 0.00/cm^) than aerobic plate count data (logw 4.10 to 3.82/cm^). Salmonella was isolated from carcasses at all sampling points with skin samples recording high isolation frequencies.The results of this study indicate that neither aerobic plate count nor total coliform counts alone is sufficient to analyse carcass contamination levels at various operational points but the two, however, are complimentary. This study has also demonstrated high levels of bacterial contamination on carcasses, which is known to be associated with poor hygiene. There appears a need to establish slaughter and dressing procedures, and quality assurance programmes based on risk assessment and maximum utilisation of resources. Meat standards also need to be set and this will need an active legislative support to improve both meat safety and quality, and hygiene standards in Zambian cattle slaughterhouses.
Gastrointestinal nematodes in traditional cattle of Zambia : seasonality and relationship between faecal egg counts and worm burden
(2012-09-04) Phiri, Denis
Faecal egg counts, differential larval counts and post mortem total worm counts were done on seventy traditional cattle from Southern province of Zambia between February and September 1997 to establish the relationship between faecal egg counts and total worm burden and to determine the seasonality of gastrointestinal nematodes in the same traditional cattle. The animals were sampled at Turn Pike slaughter slab in Kafue district on a biweekly basis at an average of five animals per visit. During the same visits, at least 20 animals per visit were checked for gastrointestinal nematode eggs in the faeces.The highest faecal egg counts were recorded during the rainy months February to April and the lowest where in the cold dry month of July. The same was observed with total worm counts. The mean monthly temperatures were also found to be positively correlated to both the faecal egg counts and the total worm counts. Rainfall was however, only found to positively correlate with faecal egg counts and not with total worm counts. In all the eight months that the study was carried out, no inhibited larvae (hypobiotic larvae) were observed in all the animals sampled.The genera identified by either coprocultures or post mortem worm counts were Haemonchus spp., Cooperia spp., Oesophagostomum spp., Bunostomum spp. and Trichostrongylus spp. The prevalence of these worms in the gastrointestinal contents were Cooperia 73 percent, Haemonchus 22 percent, Oesophagostomum two percent and Bunostomum and Trichostrongylus each at one percent. All the animals examined were found to be infected with at least one genus of gastrointestinal nematodes and of these 84 percent were infected with Cooperia, 76 percent with Haemonchus, 74 percent with Oesophagostomum 14 percent with Bunostomum and another 14 with Trichostrongylus. The different genera were compared with the faecal egg counts to determine the relationship between the different genera and the faecal egg counts. A positive correlation was found between Haemonchus spp (r = 0.5785, p<0.05), Cooperia spp (r = 0.7469, p<0.05) and Oesophagostomum spp (r = 0.5987, p<0.05) and faecal egg counts. However no relationship was found between Bunostomum, Trichostrongylus and faecal egg counts. A positive correlation (r^ = 0.57, p< 0.05) was found between faecal egg counts and total worm counts.
The epidemiology of gastrointestinal nematodes in goats in the traditional grasslands of Zambia
(2012-09-05) Nalubamba, King Shimumbo
Monthly faecal gastrointestinal nematode egg counts, coprocultures, differential larval counts and packed cell volumes of goats (according to age classes <6 months, 6 months to 1 year, 1 year to 2 years, more than 2 years) from two traditional farming areas (Chipembi and Shibuyunji) in Central Province of Zambia, were monitored over a period of 15 months from July 1994 to September 1995. The levels of infective gastrointestinal nematode larvae on pasture and monthly larval intake were also estimated using tracer goats. Each month, from September 1994 to August 1995, six goats, less than 6-month-old (tracers) shown to be free of gastrointestinal nematodes after anthelmintic treatment were grazed with a flock of naturally infected goats in Chipembi. After a month's stay, these tracer goats were removed, placed on cement-floored pens and were maintained in such helminth-free conditions for at least 3 weeks prior to necropsy and examination for adult gastrointestinal nematodes. Abomasa from the tracers were artificially digested to recover inhibited larvae. The faecal egg count pattern parallelled that of the total rainfall, being highest in the rainy season, and falling to very low levels during the dry season. The faecal egg counts from individual animals reached a peak in the middle of the rainy season (February, March) and lowest counts were observed from July to September. During all the months unfler study at least 80% of the adult goats had nematode eggs present in their faeces. Throughout the study period, goats less than one year old had faecal egg counts and prevalence which were significantly (P>0.05 ) lower than those found in more than one year old goats except during the rainy season when all animals * * were infected. Goats more than two years old had the highest intensity of infection as demonstrated by the higher faecal egg counts. Kids of less than six months revealed the lowest faecal egg counts and prevalence. The following species were identified on either postmortem worm count or by differential larval counts: Haemonchus contortus, Trichostrongylus spp., Oesophagostomum, Cooperia spp., Bunostomum spp., Trichuris ovis, and Strongyloides papillosus. Gaigeria eggs were also seen infrequently during the rainy season. H. contortus and Trichostrongylus were found to be the most predominant species observed, followed by O. columbicmum. Trichostrongylus peaked during the dry season while H. contortus and O. columbianum both peaked during the rainy season when temperature and moisture conditions favoured their development and transmission. Other nematode species revealed less defined seasonal fluctuations. Monthly larval intake of gastrointestinal nematodes was also monitored by the use of f tracers which indicated a high larval intake mid-rainy season up to the end of the rainy season. No larvae were picked up during the dry season. Inhibited larvae were only found in the months of December and May. Recommendations suitable for application in traditional areas, are made for the control of gastrointestinal nematodes.
Relationship of human and animal tuberculosis in the interface areas of the National parks of the Kafue Basin in Zambia
(2012-09-05) Munyeme, Musso
Tuberculosis is a disease of worldwide public health and economic importance. In Zambia the disease has been consistently reported in the Kafue Basin without a clear understanding of transmission dynamics in the livestock-wildlife interface. The main objective of this study was to determine the relationship between human and animal tuberculosis in the livestock-wildlife interface. In order to determine TB prevalence in cattle, a cross-sectional study was conducted using the mid-cervical comparative tuberculin test in the Kafue Basin (Lochinvap and Blue Lagoon) and a control area outside the interface areas (Kazungula District). Farmers were interviewed using a pre-tested questionnaire in order to determine TB risk factors. Tissue samples were collected from abattoirs and hunter harvested wildlife animals for isolation of TB. Sputum samples were also collected from health centers for TB isolation from humans. All cultures from these species were subjected to DNA analysis using spoligotyping to determine the Mycobacterium species causing disease in these hosts. Questionnaire results were used to build a model on risk factors for cattle TB in the study areas. A total of 944 cattle from 111 herds were subjected to the mid-cervical comparative tuberculin test. Overall at individual animal level, the prevalence of TB in all the study areas was found to be 5.50%. In Lochinvar and Blue lagoon, the individual cattle prevalence was 5.35% and 7.34% respectively. However, in the control area (Kazungula) the individual animal prevalence was lower at 0.57%. At herd level, the overall TB prevalence in cattle was herds 24.32% and a trend similar to individual cattle results was observed. These results, suggest an existence of foci of TB infection in the Kafue Basin of Zambia. Tuberculosis prevalence was observed to vary according to the type of grazing system (P = 0.000) with interface herds recording higher prevalence (11.6%) than transhumance and village herds. Herds of cattle that practiced interface grazing system were eighteen times more likely to be TB positive than those that practiced village grazing system (Odds ratio = 18.07; CI 95% = 4.3-81.0); p=0.000). These results based on the grazing system suggest that TB prevalence increased with increasing level of contact with wildlife. From the questionnaire results, logistic regression analysis revealed that herd size and grazing system were the two most significant risk factors influencing TB herd status. From the abattoir survey, gross postmortem examinations revealed a 13% organ condemnation. However, only 6.62% of the overall condemnations had characteristic TB colonies on culture. The abattoir study provided evidence of the respiratory tract as a primary route for the establishment of tuberculosis infection in cattle as 87.64% of condemned organs were lungs. In the wild animal survey, gross postmortem examination indicated a prevalence of 43% in the lechwe. Based on these findings, TB may appear to be probably maintained principally by the lech we may be due to its abundance or owing to the small sample sizes obtained from the other wildlife species. Based on the questionnaire results, no statistical association was found between keeping cattle and having a TB patient in the household (Relative risk = 1.14; CI = 0.64-1.94); p = 0.83). Further, DNA analysis of animal and human isolates indicated that there was no sharing of infection. From the DNA results, all animal isolates were M. bovis while all human isolates were M. tuberculosis. These results may indicate species adaptability in certain hosts. However, animals may still be able to transmit TB to humans, albeit at a low prevalence. Based on the generated TB model, in terms of TB control in the interface areas, the most critical factors to consider will be herd size and the grazing system.
Toxicity testing of SIDA cordifolia(Flannel weed) in goats in Zambia
(2012-09-05) Jembe, Josias
Sida cordifolia, family Malvaceae, was suspected to have caused toxicity in small ruminants (sheep and goats) at one of the farms around Lusaka. To verify the suspicion the present study was planned and undertaken. The study included (a) experimental feeding of female goats with Sida cordifolia (b) retrospective study of liver and kidney specimens from the affected farm as well as neighboring farms with suspected plant poisoning and (c) a questionnaire survey on the same farms to gather information on farm management, animal husbandry, vegetation and disease outbreaks in case there were other agents responsible for the out break at the affected farm. Three toxicity tests were conducted using 14 healthy female goats aged between 8 to 18 month and weighing 12 to 18kg body weight. The goats, all from one herd, were let to acclimatize for two weeks in a room with a concrete floor. During this period, the animals were clinically examined and deworrned. The plant used in the toxicity test was picked at flowering stage; and only tender aerial leaves together with flowers and seeds were dried in the shade, milled and stored at -10°C. The first experiment involved five goats. Two of the goats were drenched at a dosage of 5g (dry matter; D.M.)/kg body weight and another two received a dosage of lOg (D.M.)/kg body weight. One goat was used control. The goats were dosed for 5 consecutive days and observed for 10 days. The second toxicity test comprised six goats but only two completed the course having been drenched with lOg (D.M.)/kg of the milled plant material for 10 consecutive days and observed for 30 days. The third and final test involved three goats but only one completed the experiment on a dosage of 5g (D.M.)/kg for 20 consecutive days and observed for 20 days. Rectal temperature, respiratory rate, heart rate, pulse rate, and rumen motility were measured during the experiments. Signs of jaundice and photosensitivity were monitored. Serum metabolite indices known to be sensitive indicators of liver damage, gamma-glutamyltranspeptidase (GOT) and aspartate
The prevalence and differentiation of human taenia spp. infections in two districts of the Southern province of Zambia
(2012-09-05) Mwapa, Kabemba Evans
Taeniosis and cysticercosis are public health problems in many developing countries, with the former being due to the adult worm of both Taenia solium (T. solium) and Taenia saginata (T. saginatd) while the latter is due to the larval stages of T. solium. Extensive studies in pigs and cattle, which are the intermediate hosts of these important zoonotic parasites, have been carried out in Zambia. However little or no information about the infections in humans is available. Hence, the objective of this study was to determine the prevalence and the potential risk factors associated with taeniasis/cysticercosis in humans in the districts of Gwembe and Monze of the Southern province of Zambia. We also undertook to differentiate the human Taenia spp. found in the study area. The prevalence of human taeniosis was assessed using coproscopic examination and diagnostic PCR. Presence of circulating parasite antigens in urine and serum to detect cysticercosis was assessed by enzyme-linked-immunosorbent assay (Ag-ELISA). Restriction fragment length polymorphism (PCR-RFLP) was used to differentiate the two human Taenia spp. A questionnaire was administered to individuals above 12 years of age in order to obtain information on the awareness of the infection by the participants and to study other associated risk factors to taeniosis/cysticercosis infections in man. A total of 678 faecal samples were examined. Of these, 294 and 384 samples were from Gwembe and Monze districts, respectively. Of the total faecal samples examined 21 (3.1%) were positive for taeniosis after coproscopic examination. PCR XX was conducted on a sub sample of 200 from the 678 faecal samples and 21 (10.5%) were found positive for taeniosis. There was no significant difference in prevalence between the two districts on both tests and perfect agreement (kappa = 0.851) was found between the two tests. Urine Ag-ELISA analysis gave a total cysticercosis prevalence of 13.4% (n = 627). No significant differences in cysticercosis prevalence were detected between individuals from Gwembe 37 (13.8%) and Monze 47 (13.1%) districts. There was no statistical association between gender or age group and positivity on either coproscopic examination or urines Ag-ELISA. Of the 101 serum samples collected from both urine Ag-ELISA positive and negative individuals, 8.9% had cysticercal antigens while 47.5% had antibodies. Comparing the three tests, only slight agreement was found between urine Ag-ELISA and serum Ab-ELISA. Even though the agreement was very slight, it was statistically significant (p < 0.05). Upon RFLP, all extracted Taenia DNA was confirmed to be that of T. solium and no pattern corresponded to that of T. saginata. The following risk factors were noted to be present despite not being statistically significant; lack of pork inspection at slaughter, consumption of pork with cysts, selling of pork infected with T. solium cysticerci, free-range pig husbandry system and poor sanitation, thereby allowing pigs access to infected faeces because of absence of toilets. This study showed a high prevalence of T. solium taeniosis/cysticercosis in humans in the surveyed areas, and that all the necessary factors required for the transmission of the parasite are present. The life cycle of T. solium is bound to be sustained by pigs being allowed access to infected human faeces because villagers with no toilets defaecated in open bushes. Consumption of uninspected cysticercosis-infected pork by villagers further enhances this maintenance of the parasite. It is evident from this study that T. solium infection poses a high public health risk not only in the study areas but also in urban areas due to migration of tapeworm carriers. The vast baseline data gathered thus far on the status of the diseases in humans should give the impetus to conduct further taeniosis and cysticercosis prevalence study in humans not only in these areas but also in other areas where pigs are raised.
Some aspects of the behaviour,ecology and vectorial capacity of glossina brevipalpis newstead and other flies in the Luangwa valley of Zambia
(2012-09-05) Maseko, Alikhadio
Studies were carried out in the South Luangwa National Park, located in the Luangwa Valley Zambia., on the behaviour, ecology and vectorial capacity of G. brevipalpis and G. m. morsitans and G. pallidipes. The catch of G. brevipalpis was low in odour baited epsilon, NGU2G, F3 and biconical traps throughout the year. It was, however, observed that the flies were attracted to the traps but did not enter. Glossina brevipalpis was not easy to catch with ordinary fly rounds, but with the use of an electric screen fly round, more of this fly were caught. The best sampling system for G. brevipalpis was found to be artificial refuges which worked better in the hot dry season from mid-August to mid-December. Tsetse flies started entering refuges from 09:00 h and left after 16:00 h and this is the time in which tsetse flies rest because the environmental conditions negate tsetse fly survival during this period. Refuges with a total volume of at least 200 liters were more efficient for as long as they were dark, insulated and provided with shade. Glossina m. morsitans was caught more on fly rounds than using traps while, G. pallidipes was captured more with traps than in any other sampling system used. Like G. brevipalpis, both G. m. morsitans and G. pallidipes responded well to artificial refuges. Glossina brevipalpis was concentrated in the riverine vegetation type throughout the year while G. m. morsitans and G. pallidipes were more concentrated in the mopane and thicket vegetations. Glossina brevipalpis was also observed to be a very localised fly to the riverine vegetation and rarely leaves it. Using a circular setting of seven artificial refuges of 300 m radius to the one centrally placed gave a recapture rate of 7% over a period exceeding three weeks. It was noted that even in such a small area used some refuges outside the riverine vegetation but within the said radius did not capture any G. brevipalpis. Although the catches for artificial refuges and* traps were different in terms of species composition, the age distribution by both ovarian and wing fray analysis were similar. There was also*no significant differences in infection rates of G. brevipalpis (3.3%), G. pallidipes (3.5%) and G. m. morsitans (4.4%). Species identification of trypanosomes were investigated for G. brevipalpis using a protocol which was developed specifically to isolate trypanosome DNA in tsetse fly parts for amplification by the PCR technique. The technique was able to identify 100% of the T. congolense (Savannah) and 43% of the f. congolense-like infections in tsetse fly midguts were identified to be T. brucei. Trypanosoma vivax and T. simiae primers did not amplify and reasons for this are suggested. Glossina brevipalpis was therefore, shown to be a potential vector of African trypanosomosis and hence further studies on the ecology and control of this species are recommended.
Aetio-Pathological Investigations Among Fish Species presenting Epizootic Ulcerative Syndrome (EUS) In the Zambezi river Basin in sesheke District of Zambia
(2012-09-17) Songe, Mwansa Mathilda
This study was conducted in Sesheke district of Zambia to investigate the etio pathological changes that occur in fish species presenting with Epizootic Ulcerative Syndrome in the Zambezi River Basin. The disease is endemic in Asia, but it is being reported for the first time in Africa. A total of two hundred and seventy (270) fish belonging to sixteen species were sampled from seven (7) major fishing camps in Sesheke district of Zambia during the study period. These species were: Clarias ngamensis, C. gariepinus, Barbus poechii, Tilapia sparmanii, Seranochromis angusticeps, Brycinus lateralis, Micralestes acutidens, Sargochromis carlottae, Hydrocinus vittatus, Phryngochromis acuticeps, Schilbe intermedius, Hepsetus odoe, Labeo lunatus, Oreochromis andersonii, B. unitaeniatus and B. paludinosus. Among the fish samples collected from the field, only Tilapia sparmanii did not show any macroscopic or microscopic lesions.The disease was diagnosed by the histopathological technique. Hematoxylin and Eosin standard stains were used. Grocott stain was used to confirm the presence of fungal hyphae in the tissue sections. Furthermore, samples were cultured for isolation of Aphanomyces invadans, the causative agent of EUS.Following isolation, the infectivity and role of A. invadans in the etiology of fish skin ulceration in Oreochromis niloticus, Oreochromis andersonii and Barbus paludinosus were investigated in the laboratory through the pathogenicity and challenge studies. Of these species, O. niloticus did not show any visible lesions, even after 32 days post-inoculation. The other two species, on the other hand, were successfully infected with the fimgus after 15 days post-inoculation, upon exposure after disruption of the epidermis. The deeply penetrating ulcers observed in O. andersonii and B. paludinosus after the challenge were characterized by dermatitis, myofibrillar degeneration and necrotizing granulomatous myositis. The experimentally induced lesions also exhibited invasiveness, often involving the kidney, confirming Koch's postulates. Natural infections were characterized by dermatitis, hemorrhages, severe muscular necrosis, necrotizing granulomatous inflammation and myofibrillar degeneration. Invasiveness involving internal organs was also observed. The study has demonstrated that EUS can be experimentally induced in O. andersonii and B. paludinosus after exposure to A. invadans zoospores isolated from the Zambezi river basin.The challenge experiments are significant in establishing which fish species are susceptible to EUS. In this case O. niloticus would be an excellent culture species for the emerging fish farmers in Zambia, owing to its comparative resistance to the disease. It is, therefore, important that these studies are continued in a number of species. This will enhance the true understanding of which species can be affected by EUS in the Zambezi river basin.
Prevalence, Characterization and Transmission of Cryptosporidium species between animals and Humans on Diary Farms in Zambia
(2012-09-17) Siwila, Joyce
In the last two decades, Cryptosporidium infection has increasingly become important as a cause of diarrhoea in humans especially in children under the age of 5 years and in the immuno-compromised, particularly those with Human Immunodeficient Virus or acquired immunodeficiency syndrome (HIV/AIDS). This is especially so in developing countries such as Zambia where there is high HIV/AIDS prevalence, which is currently estimated to be 16% among adults of reproductive age. There are, however, no known reports in Zambia of whether farm workers who are constantly in touch with animals are at risk of getting Cryptosporidium infection directly from these animals and information on genotypes involved is also lacking. The absence of such important information led to the formulation of this study. The aims of this study were to determine the presence of Cryptosporidium infection in dairy calves and in lambs and goat kids on selected dairy farms on one hand and in humans working with animals and members of their households on the other hand, using a copro-antigen enzyme linked immunosorbent assay (ELISA). Management factors and potential risk factors of infection were also investigated through questionnaires to find out if there was any possible association with the occurrence of Cryptosporidium infection in animals and humans. Genotypes of parasites isolated were also determined. The faecal samples were collected per rectum from 207 calves, 39 lambs and 14 kids, aged six weeks and below belonging to 20 dairy farms in Lusaka and Central provinces between October 2004 to March 2005. Stool samples were also collected from 289 humans of various ages ranging from 0 to 60 years after informed consent. The faecal consistency was noted for each sample after which the samples were frozen until analyzed. The copro-antigen ELISA analysis showed an overall Cryptosporidium prevalence of 33.8% in calves. When the farms were divided into large-scale and small-scale dairy farms based on the total number of animals reared on the farm, the prevalence was found to be 39.02% for the large-scale farms and 13.95% for the small-scale farms. The prevalence in lambs was 2.6% while that for the kids was 7.1%.Out of the 289 human stool samples from 89 families that were analyzed, 6.2% were positive for Cryptosporidium. Ten (5.7%) of these were males while 8 (7.2%) were females. Eight of the positive males were farm workers while two were non-farm workers. All the positive females were non-farmnvorkers. The highest number of positive individuals was in the age range of 21-30 years. The positive humans were from eight farms only out of the 20 farms sampled. Results from the questionnaire survey on calf management factors and their association with infection with Cryptosporidium, indicated a significant difference in prevalence between individually housed calves and those that were housed in groups (X^=33.420, P<0.0001). The prevalence was higher in individually housed calves (52.4%) as compared to those housed in a group (16.3%). The frequency of bedding removal was also significantly associated with the prevalence of cryptosporidial infection (^^=38.875, P<0.0001). Bottle/bucket feeding was also associated with the infection (x^= 13.034, P=0.04) as opposed to suckling. Cryptosporidium infection was also significantly associated with faecal consistency, with prevalence of 51.4%, 38.6% and 10% for normal, watery and pasty faeces, respectively (x^=9.228, P=0.010).Questionnaires were administered to 89 households to determine if contact with animals, occurrence of diarrhoea in the home, water source and sharing water source with animals were associated with cryptosporidial infections in farm workers and their families. The individuals that had contact with neonatal calves were 2.091 times more likely to be infected with C. parvum than those that did not have contact. Those that had diarrhoea in the home were also 2.295 times more likely to have the infection but the association in both cases was not significant. Age was also not significantly associated with Cryptosporidium infection (x^=8.825, /'=0.184).Twenty positive calf samples, one lamb and one kid samples were analyzed using Polymerase Chain Reaction (PCR). Amplification products using the Heat Stock Protein (HSP-70) gene and the 18S rDNA gene were obtained for 20 isolates from calves and for the lamb and kid samples. After sequence analysis, Cryptosporidium parvum bovine genotype, C bovis and a deer-like genotype were identified from calf isolates.'The lamb sample revealed C. parvum bovine genotype while the kid sample revealed C. suis.Amplification products for the HSP-70 gene and 18S rDNA gene were also obtained for nine and 14 human samples, respectively. Four samples did not amplify on both the 18S rDNA gene and the HSP-70 gene. Sequence analysis on the amplified samples revealed C. parvum bovine genotype and C. hominis. These genotypes were found in both the fann workers and non-farm workers. From this study, it can be concluded that Cryptosporidium infections are prevalent in Zambian dairy cattle, sheep and goats. It can also be concluded that Cryptosporidium infection is prevalent in humans working and living on dairy farms. The C. parvum bovine genotype was found in humans, an indication that humans are at risk of infection and do get infected with the animal type of Cryptosporidium parasites. However, the strength of association between the potential risk factors and the occurrence of cryptosporidiosis could not be conclusively established. In view of this, it is, therefore, recommended that fiarther studies be done to include other areas of the country and further genotyping of Cryptosporidium isolates from humans also be expa
Viability of Mycobacterium Bovis in traditionally processed Sour Milk and the prevalence of Bovine Tuberculosis in Namwala district of Zambia
(2012-09-17) Sitima, Almond Casmir Madandu
Tuberculosis is a debilitating disease caused by the bacteria of the genus Mycobacterium. The disease has been recognized for centuries and its causative agents have continued to be studied to date. Mycobacterium species cause disease in animals, birds and humans. They can cause cross infection between the hosts. The most important species in the genus are Mycobacterium bovis and Mycobacterium tuberculosis. These two cause zoonotic tuberculosis and can be excreted in milk of co.ws when udders are infected making the milk to be a very good vehicle for mycobacterium transmission.Several authors have indicated that tuberculosis is transmitted by consuming contaminated milk. The Ila people of Namwala district in Zambia are cattle keepers and consume a lot of milk both as fresh and sour. MilkJs allowed to sour in a bottle gourd {Lagenaria siceraria) commonly known as a calabash {Insuwa-lla. and Tonga, A^5Mpa-Chewa, Insupa-Qtrabo). The Ila people boil milk for immediate use but that meant for sour milk remains unboiled. The prevalence of bovine tuberculosis has been reported to be as high as 30 percent in their herds of cattle based on assumptions and abattoir returns. The risk of humans to be infected with mycobacterium may be seen to be high. Therefore aims of the study were; to assess the viability of M. bovis in traditionally processed milk, to estimate the prevalence of bovine tuberculosis in cattle of Namwala district and to identify the flora in the calabash.Within Namwala district data was collected from Baambwe and Maala Villages due to proximity and high cattle populations. Tuberculin test was used to estimate the prevalence of bovine tuberculosis. The tuberculin used was Purified Protein Derivative of Mycobacterium bovis and Mycobacterium avium manufactured in the Netherlands. Ten herds of cattle, totaling 507 cattle were tested. To assess the effect of traditional milk processing on M. bovis, a laboratory experiment was set to imitate the traditional method of souring milk. M. bovis was inoculated into fresh milk which was mixed with a cocktail of souf milk collected from calabashes . Samples of this milk were taken at intervals to measure the pH and for culturing on Lowenstein-Jensen medium, to determine the viability of the M. bovis and M tuberculosis . Samples of sour milk were taken from 14 calabashes for the identification of the flora in the calabashes. M. bovis was recovered at the various stages of the pH transition from 7.0 to 3.0 and at all sampling intervals from the milk in which it was inoculated experimentally. The obtained results indicate that raw milk containing M. bovis is not able to eliminate the organism in the process of souring the milk within the time frame of optimal consumption (24-48 hours).The overall prevalence of bovine tuberculosis was found to be 12.8 percent. In the females it was found to be 13.5 percent while in the males 8.6 percent. It was highest, (17.6 %), in the age group of 41-55 months old while the youngest 1-24 months had the lowest (6.3 %). The herd prevalence of the ten herds varied between 9.4 and 18.8 percent.The high quantity of the lipids in the cell wall of the M. bovis was thought to account for the recovery of viable Mycobacterium in sour milk. Bacteria and yeast found to form the flora of the calabashes were mostly the Gram positive rods of the lactobacillus species and Candida species respectively. It was concluded from the present study that the prevalence of bovine tuberculosis in Namwala district was high as compared to other districts in the country and that the traditional way of sour milk processing' presents a public health risk.
Incidence and characterisation of Salmonella Enteritidis in poultry products and human diarrhoea cases in Lusaka District, Zambia
(2012-09-17) Hang'ombe, Bernard Mudenda
This study was conducted to find out the incidence of Salmonella enteritidis in table eggs and chicken carcasses entering the consumer market in the city of Lusaka. Diarrhoea stool samples from humans admitted to the University Teaching Hospital (UTH) were also included in the study to investigate Salmonella enteritidis in the population. Table eggs were collected from eight randomly selected layer farms in and around the city. Specimens from the chicken carcasses were sampled from a big processing plant operating in Lusaka city. Two thousand four hundred (2400) commercially purchased table eggs and three hundred eighty two (382) chicken carcasses were cultured on suitable media for isolation of Salmonella enteritidis. The shell membranes and yolks from table eggs were pooled in units of ten and cultured. Nine (3.75 per cent) of the two hundred and forty samples of table eggs were found contaminated with Salmonella enteritidis, while eighteen (4.7 per cent) of the carcasses sampled were found positive for Salmonella enteritidis. Other Salmonella serovars isolated from the chicken carcasses were Salmonella infantis. Salmonella gallinarum and Salmonella mbadaka while Salmonella gallinarum was the only other serovar from the table eggs. A total of eighty six (86) diarrhoea stool samples from humans obtained from UTH, Lusaka were also cultured and eight of these were found positive for Salmonella typhimurium. Phage typing of the Salmonella enteritidis isolates showed that all the isolates from the table eggs and seven from chicken carcasses belonged to the enteropathogenic invasive PT4, while three from the carcasses were PT7 and eight were untypable. Efforts were made to characterise the Salmonella enteritidis isolates by carrying out pathogenicity test, biochemical test and antibiogram test. The characterisation involving animal models of mice, embryonated eggs and seven days old chicks displayed that Salmonella enteritidis isolates from the table eggs were more virulent than the isolates from the chicken meat. Biochemical test did not reveal anything significant. Salmonella enteritidis isolates from table eggs and chicken carcasses tested for antibiotic sensitivity had several features in common. They were sensitive to amoxycillin, ampicillin, co-trimoxazole, furazolidone, gentamycin and tetracycline while Salmonella typhimurium isolates from diarrhoea cases were resistant to amoxycillin and ampicillin. Several Salmonella mbadaka isolates showed resistance to tetracycline. Salmonella enteritidis has been isolated from the table eggs and poultry meat carcasses for the first time in Zambia. The results of the study further demonstrated that poultry products from Zambia have a higher incidence of Salmonella enteritidis contamination compared to reports in other parts of the world. It warrants a planned epidemiological study of Salmonella enteritidis in the country to formulate appropriate control measures.
Co-joint trematode infections in cattle from Kafue and Zambezi river basins of Zambia
(2012-09-17) Yabe, John
This study investigated the heterologous interaction among Fasciola gigantica, Schistosoma spp. and Amphistomum spp. co-joint infections in cattle based on egg and worm counts. A total of 315 cattle from trematode endemic areas along the Kafue and Zambezi flood plains were screened at Turn Pike abattoir for either F. gigantica in the liver, Schistosoma spp. in the mesenteric veins and/ or Amphistomum spp. in the rumen. One hundred and thirty three of the abattoir examined cattle harboured one, two or all three trematodes. Faecal samples, livers, mesenteries, lungs, kidney, spleen, abomasum and rumens from fifty randomly selected trematode infected cattle were collected for ftirther laboratory examination. There were heavy Amphistomum (mean ± SEM = 622.08 ± 97.87), low Schistosoma (mean ± SEM = 3*3.68 ± 7.44) and low Fasciola (mean ± SEM = 19.46 ± 4.58) worm burdens. There was no significant difference (x^ =575.34, p =0.923) between F. gigantica and Schistosoma worm burdens. A significant difference (x^ =1210, p =0.038) was observed between F. gigantica and Amphistomum worm burdens. A total of 32% (n = 50) harboured all the three trematodes, 66% had F. gigantica and Amphistomum spp. infections, 52% had Schistosoma spp. and Amphistomum spp. infections while 32% had F. gigantica and Schistosoma infections. A positive correlation (p = 0.014) was obtained between F. gigantica and Amphistomum worm burdens. There was no correlation between Amphistomum and Schistosoma worm burdens (r = 0.15, p = 0.302) and between F. gigantica and Schistosoma worm burdens (r = -0.12, p = 0.390). Schistosoma faecal egg and tissue egg counts had positive correlations (p < 0.001) with worm burden. Fasciola eggs were also detected in the liver, lung, kidney, mesenterium and spleen. Fasciola tissue egg counts were significantly higher than faecal egg counts (p < 0.001). Histopathological examination of the lungs did not confirm the presence of Fasciola eggs in the tissue. Based on these findings, it may be concluded that there is no significant cross-protection among these trematodes in cattle in endemic areas. Therefore, existence of co-joint infections and lack of cross-protection among F. gigantica. Schistosoma and Amphistomum infections in endemic areas should be considered when formulating control measures of trematode infections.
A study of the fertility status of a commercial dairy herd in Zambia
(2012-09-17) Schneebeli, Markus.
The dairy industry in Zambia is a vital sector of the food industry and it has not been given the attention it deserves. Aspects such as level of production and factors affecting production have not been examined in the recent past.The reproductive performance of dairy animals is a field of major importance in veterinary medicine and subject to an enormous amount of dynamic research. Knowledge about the events determining reproduction and methods of influencing and improving the same has increased significantly over the past years, but the benefit of this to developing countries has so far been unsatisfactory. Milk production of dairy animals is largely dependent on the reproductive performance of individual animals. No recent studies on this subject are available in Zambia and it was therefore felt that a detailed study of the reproductive performance of dairy animals under local Zambian conditions was required. A study of the reproductive performance and fertility problems encountered on a commercial dairy farm near Lusaka was performed, covering a period of four years. The records of reproductive performance over three years were analysed and cull cows and heifers examined over a one year period. The hypothesis which was followed during this study was to confirm the assumption that there were no significant problems present in the culled cows and heifers from this particular dairy, but that the reproductive performance was poor due to managerial problems. The examination of cull cows and heifers included record analysis, gross post-mortem examination, bacteriological examination of uterine swabs and microscopic examination of histopathological sections of uterine tissue. The results revealed a high incidence of disposal of dairy cows and heifers for reproductive reasons. The examination of herd records, which included the reproductive history of 1108 cows after calving, suggests that this disposal was largely due to management problems such as heat detection rate and timing of insemination in this herd where artificial insemination was in use. The examination of slaughtered animals, which involved 92 animals did not reveal any significant findings which would be responsible for the reproductive failure of the majority of disposed animals. A seasonal pattern of slightly improved reproductive performance with regards to conception to first service has been observed, and this should be taken into consideration when deciding on future breeding policies in dairy herds in Zambia, This period occurs during the early winter, when environmental factors such as ambient temperature and humidity drop, reducing stress on the animal and improving conception rates. The main reason for the reproductive failure of the examined animals is attributed to poor heat detection and timing of insemination.It was concluded that the reproductive performance of dairy animals in Zambia can meet targets set for developed countries, provided the level of management is improved and knowledge of the control of the reproductive cycle of the dairy cow is implemented.
Haematological and Blood biochemical changes in the pathophysiology of trypanoma congolese infection indigenous Zambian goats
(2012-09-17) Witola, William Harold
Trypanosomosis is an economically important parasitic disease of almost all domesticated animals in Zambia. However, very little work has been done to estabUsh the pathophysiology of the disease in animals in Zambia. The changes in haematological and blood biochemical parameters of infected animals are important in disease prognosis, treatment rationale and in determining the organs which have undergone pathological changes. Goats are important hvestock in tsetse-infested areas of Zambia probably due to their " exhibitance of partial trypanotolerance.The course of experimental Trypanosoma congolense (IL3000) infection in indigenous Zambian goats was followed during which the parasitaemia, clinical parameters, haematological parameters and serum proteins profiles were determined and erythrophagocytosis was investigated as a mechanism of anaemia. Parasitaemia was determined using the bufiy coat method, while the packed cell volume (PCV) was measured by the haematocrit method. The red blood cell (RBC) coimts, white blood cell (WBC) counts and haemoglobin (Hb) were determined using an electronic cell counter. The RBC indices were derived from the measured PCV, RBC counts and Hb. Erythrophagocytosis was investigated using radioisotope assays and microscopic methods. Serum total protein and albumin were determined by chemical methods (Biuret and Bromocresol green dye), the serum globiiUns concentration calculated by subtraction of globulin concentration from the serum total protein concentration and the A:G ratio determined.The strain of Trypanosoma congolense used was pathogenic, it produced disease in the goats characterised by rapid progressive anaemia, early phase leucopenia, high parasitaemia and classical clinical signs of trypanosomosis. Statistically significant (P < 0.05) mean reductions in values of PCV, haemoglobin and RBC counts were observed between the infected and the control goats starting from as early as 17 days post-infection and lasting up to 56 days post¬infection. Erythrocyte indices were stable throughout the infection period resisting in normocytic-normochromic anaemia. Significant (P < 0.05) evidence of erythrophagocytosis was observed using both radioisotopic and microscopic techniques. The mean serum total protein and globuUn levels increased significantly (P < 0.05) within 3 weeks of infection and remained elevated until the end of the experiment. It was evident the mean albumin levels did not show any significant (P > 0.05) variations while the A:G ratio significantly (P < 0.05) dropped in the fifth week and remained consistently low.This study showed that T. congolense infection in indigenous Zambian goats causes anaemia and that erythrophagocytosis is one of the mechanisms of this anaemia. Moreover, marked changes in serum protein profiles develop which are associated with the pathophysiology of the disease.

Browse

Browsing Veterinary Medicine by Issue Date

Results Per Page

Sort Options