Changes in the adrenal gland and cortisol secretions in experimental acute Trypanosoma brucei brucei infection in Sahel bucks

The effects of experimental acute Trypanosoma brucei brucei infection on the function and structure of the adrenal gland of Sahel bucks were studied for forty days. Eight Sahel bucks aged between 8 and 15 months were used. They were divided into two groups of five (infected) and three (uninfected) bucks. Group I were inoculated with 1ml containing about 1×10⁶ trypanosomes (Trypanosoma brucei brucei, Federe strain) via the jugular vein. Group II was uninfected control. Parasitaemia in the infected bucks appeared 3-4 days post-infection. The mean serum cortisol concentrations of the uninfected control and the infected groups at day 0 were 3.33 ± 0.44 μg/dl and 2.4 ± 0.29μg/dl, respectively. By day 4 post-infection, the mean serum cortisol concentration of the infected group increased to its peak value of 21.8 ± 6.25μg/dl compared to 3.0 ± 0.86 μg/dl of the uninfected control on the day all infected bucks became parasitaemic. Grossly, the adrenal glands of the infected group were enlarged. Histopathologically, there was adrenal cortical hypertrophy in the infected group. The results indicate that acute trypanosomosis due to experimental T. brucei brucei infection in Sahel buck caused hypertrophy of the adrenal gland and a significant increase in the circulatory cortisol concentration of the infected bucks at the onset of parasitaemia followed by a decrease to pre-infection cortisol concentration till the end of the 40 days duration of the experiment. Further study on the long-term effect of experimental Trypanosoma brucei brucei infection on the adrenal gland of Sahel bucks is recommended

Phytochemical composition and toxicity of the aqueous extract of Parkia biglobosa pods in adult Clarias gariepinus

The phytochemical composition and toxicological evaluation of the aqueous extract of Parkia biglobosa pods in adult Clarias gariepinus was investigated over a 96-h exposure period. The aqueous extract of the pods was freeze-dried and screened for its phytochemical constituents. This revealed the presence of glycosides, alkaloids, saponins, steroids and triterpenes, tannins, carbohydrates and flavonoids but no anthraquinones and fixed oils. The fish were exposed to varying concentrations of the extract in a static acute toxicity bioassay. The exposed fish showed initial signs of agitated and erratic movements followed by signs of respiratory distress and abnormal nervous compromise, including mortality in some of the exposed fish. No such obvious signs of toxicity were recorded in the unexposed control fish. The appearance and intensity of the signs were both concentrations and exposure period-dependent. Mean mortality was significantly (p<0.05) related to extract concentrations and exposure period. The median lethal concentration of the extract in exposed fish over the 96-h exposure period was calculated to be 115.38 mg/l. Parkia biglobosa pods contained some toxicologically active constituents that can be meaningfully exploited to harvest fish from water bodies. However, this should be done with great care as the abusive use (higher concentrations) of this extract could result in extract residues in the exposed fish that might pose a risk to the consumers of such fish.Keywords: Clarias gariepinus, Parkia biglobosa pods, phytochemical constituents, toxicity

Toxicological Evaluation of Ethanol Extract of Adenium obesum Stem Bark in African Catfish, Clarias gariepinus

The toxicity of ethanol extract of Adenium obesum stem bark as a tool foraquaculture pond management prior to the stocking of desired fish species was evaluated in Clarias gariepinus over a 96-h exposure. The fish were exposed to 6.25 mgL-1, 7.50 mgL-1, 8.20 mgL-1, 8.80 mgL-1 and 10.00 mgL-1 of the extract and a control in an acute static toxicity bioassay after performing a range finding test to determine the median lethal concentration (LC50) of the extract. Exposed fish showed signs of changed behaviours with adaptive responses, respiratory distress and nervous compromise, including mortality in some of the exposed fish. The appearance and intensities of the observed signs were concentration and exposure period-dependent. An LC50 value of 7.35 mgL-1 was establishedfor the extract in the exposed fish where mean mortality was significantly (p<0.05) concentration and exposure period-dependent. The toxic nature of the extract in the exposed hardy fish can be exploited for effective aquaculture pond management against some unwanted predatory and weed aquatic organisms. However, the indiscriminate use of higher extract concentrations could seriously jeopardise the biodiversity of any aquaticenvironment

Farmers' Awareness of Marek's Disease and Biosecurity Practices in Poultry Production in Selected States of Nigeria

The relationship between Marek's disease (MD) and factors responsible for the continuous enzootic outbreaks in Nigerian poultry farms were investigated. A structured questionnaire was served to test the level of awareness of the poultry farmers in different locations in 2009. The retrieval rate was 68.0% (150/200) from farmers in Oyo, Enugu, Plateau, Kaduna, Kano, Nasarawa and Jigawa States. Seventy nine percent of farmers have heard about Marek's disease, while 87.9% vaccinated against MD. It was observed that the risk factors for Marek's disease using odds ratio analysis to test for association were statistically significant. A comparison between the risk of having Marek's disease infection in intensive and semiintensive management systems with extensive was highly significant (OR 29·6 and 5.0 at 95% CI, P < 0.0001) respectively. Eighty five percent of farmers with the same source of chicks complained of having MD,while 94·7% raised chicks separately from adult birds which was highly significant (OR 8.2 and overall p = 0.0009). Statistical analysis showed no significant difference (p = 0.5335, 0.1783, 0.0680 and 0.0840) respectively for gender of poultry farmers, closure of poultry farm due to MD, poultry house proximity to other neighbouring farms and source of water used. Marek's disease was still not popular among some farmers; unvaccinated birds served as carriers resulting in difficulty to control. Strict biosecurity was recommended to limit early exposure of chicks to wild or field virus beforethe establishment of vaccinal immunity, proper handling of Marek's disease vaccines and good management practices.KEYWORDS: Marek's Disease, Poultry Farmers, Awareness, Biosecu rity, Practices, Nigeri

ELEMENTAL ANALYSIS OF THE LEAVES OF VERNONIA AMYGDALINA AND ITS BIOLOGICAL EVALUATION IN RATS

Elemental analysis of the leaves of Vernonia amygdalina Del., revealed adequate concentrations of some elements, such as iron (1500+111 ppm) and calcium 10100+895 ppm) that are believed to be essential for normal growth. The plant was evaluated in relation to tissue damage, in sixteen male rats (Wistar strains) with average weight of 39.71g and aged 4 to 6 weeks. They were fed orally for 65 days with amended diets containing 25% (w/w), 50% (w/w) and 75%(w/w) powdered V. amygdalina leaves mixed with standard ECWA grower mash. The control rats were fed only with the standard diet. At the end of the experimental period, it was found to grossly, turn the skin of the treated rats lighter than that of the control group. However, microscopical examinations showed that all the various tissues are of normal architecture with good cellular morphology. On this basis V. amygdalina could be regarded as relatively safe to consume, and at the doses tested might be of nutritional importance for both animals and human beings. Key Words: Vernonia amygdalina Del., Asteraceae, leaves, elements, wistar rats, tissues. Nig. J. Nat Prod. And Med. Vol.5 2001: 13-1

The prevalence and seasonality of livestock diseases in Zaria, Nigeria:A ten-year necropsy study

A ten-year (1986-1995) record of necropsy report on diagnosed livestock diseases in Zaria, Kaduna State is evaluated to determine the prevalence and seasonal occurrence of the major livestock diseases in the Northern part of Nigetja. A total 1093 animals comprising 132 cattle, 240 goats, 318 sheep, 20 horses, 47 pigs and 336 dogs were examined at necropsy. Some diseases such as cowdriosis, Pneumonia, Ectoparasitism, and Haemonchosis showed seasonal fluctuation while others like Babesiosis, Trypanosomiasis and physical injuries were evenly distributed throughout the year. The major problem of livestock in Zaria was Pneumonia (247 cases) with a seasonal occurrence or 38.6% and 61.31% for the dry and rainy seasons respectively. During the rainy season, cowdriosis (17.42%) in cattle, Pneumonia (25.0%, 21.10% and 20.0%) in goats, sheep and horses; gastroenteritis (14.89%) and starvation/malnutrition (14.89%) in pigs and rabies (8.93%) in dogs were the major problems. Starvation/malnutrition (4.17%) in Goats and gastroenteritis (12.5%) were more prevalent during the dry season. The relevance of this report to effective control measures for the livestock resources in Nigeria is also highlighted.Key words: Prevalence, Seasonality, Diseases, necropsy, Livestock

Prevalence of Besnoitia besnoiti antibodies in bovine sera and milk in Northern Nigeria

Besnoitia besnoiti, a re-emergent parasite of cattle in Europe, occurs in many countries of Africa and other parts of the world. Clinical observations and incidental findings of B. besnoiti in cattle have been reported in the Southern and Northern regions of Nigeria, but the prevalence of antibodies against this parasite is not yet known. This investigation was designed to determine the seroprevalence of bovine besnoitiosis in Northern Nigeria. A total of 400 cattle were selected at random through cluster sampling of herds from two Local Government Areas (LGA) each, of 5 States in the region (Kano, Kaduna, Katsina, Sokoto and Borno States), between May, 2008 and November, 2009. Sera samples obtained from cows, bulls and calves, and milk from lactating cows with suckling calves were screened with indirect immunofluorescent antibody technique (IFAT) for antibodies to B. besnoiti. Out of the 400 samples 321 (80.3%) were positive for antibodies to B. besnoiti. Cattle sampled in Borno had the highest (87.5%) prevalence of antibodies to B. besnoiti, while those sampled from Katsina State had the least prevalence (62.3%). Wamako LGA of Sokoto State had the highest prevalence of the antibodies (100.0%), while Dan Musa LGA in Katsina had the least prevalence (53.0%) among the ten LGA sampled, however, these differences were not statistically significant (p > 0.05). Similarly, the overall prevalence of antibodies to B. besnoiti did not vary significantly between bulls (84.0%) and cows (79.0%), or in the dry (83.6%) and wet (77.1%) seasons (p > 0.05). The high prevalence of antibodies to B. besnoiti in cattle in Northern Nigeria indicates an endemic state of the disease in this region.Keywords: Antibodies, Besnoitia, Cattle, Northern Nigeria, Prevalenc

Influence of pulmonary lesions on some haemotological parameters of camels (Camelus dromedarius) in Northwestern Nigeria

Blood samples from external jugular vein of camels presented for slaughter at randomly selected slaughter houses in northwestern Nigeria were collected. This is to determine some haematological baseline data and to investigate the influence of pulmonary lesions on the blood parameters studied. Accordingly blood samples from 500 camels presented were collected and examined. Three hundred and twenty (320) camels sampled and examined showed one or more gross and microscopic pulmonary lesion(s) which include: acute pneumonia 232(46.4%), hydatid cyst 14(9.2%), pulmonary haemorrhage 3(0.6%), pulmonary abscess 13(2.6%) focal emphysema (12(2.4%) and pulmonary atelectasis 46(9.2%). while 180 camels sampled showed no detectable pulmonary lesion. There were relative increases in the PCV (p=0.422), RBC (p=0.411) and haemoglobin concentration (p=0.321) in camels with pulmonary lesions when compared to the values from camels with normal lungs. However, the differences were not statistically significant (p>0.05). The total WBC was significantly increased (p=0.011) in the camels that had lung lesions. Nevertheless, the differential white blood cell counts shows no statistical difference between the groups, except on the eosinophils count which were significantly higher (p=0.015) in camels with lung lesions. The calculated erythrocytes indices showed significantly higher MCH (p=0.02) and MCHC (p=0.048) in the camels with lung lesions (p<0.05), although the MCV was not significantly different between the groups. The total plasma protein was not significantly different between the groups (p=0.194). It was concluded that pneumonia or other lung lesions may have influence of the blood parameters observed in this environment.Keywords: Camel, Haematology, Lung lesion, Northwestern Nigeria

Study on the infectivity of Trypanosoma evansi isolate in Savannah brown bucks

No Abstract

Sialyltransferase activity probably counteracts that of sialidase as one of the possible mechanisms of natural recovery or stabilization of erythrocyte mass in trypanosome-infected animals - A perspective

Attempts to unravel the mechanisms of development of anaemia in trypanosome-infected animals yielded varying reports with those that implicate trypanosomal sialidase (SD) being among those thatenjoy prominence. Significant cleavage of sialic acid (SA) on erythrocyte membranes and terminal positions of erythropoietin (Epo) by SD, which is released during trypanosome infection of animals,results in their rapid clearance and destruction by cells of the mononuclear phagocytic system and in addition, in the case of Epo, decreased biologic activity of the hormone with consequent development of anaemia. Observations on free serum and erythrocyte surface SA profiles of trypanosome-infected animals suggest possible involvement of sialyltransferase (ST) in recovery or stabilization of red blood cell mass, which seems to be a probable explanation as to why some trypanosome-infected animals either recover from the anaemia or run a chronic infection with very low but stable erythrocyte mass.The speculated roles of ST open up a new and, probably, promising area of research; especially, if identification of mechanisms of natural resistance to trypanosome infection is of prime consideration inthis contemporary period of research in molecular medicine