Volume 5, Issue 1, 2008
https://hdl.handle.net/13049/416
Botswana Journal of Agriculture and Applied Sciences2024-03-29T14:40:35ZThird stage lanae of Contracaccuin species in catfish (Clariasgariepinus) from Gaborone dam, Botswana
https://hdl.handle.net/13049/434
Third stage lanae of Contracaccuin species in catfish (Clariasgariepinus) from Gaborone dam, Botswana
Mushi, E.Z.; Binta, M.G.; Padiso, C.M.
A study was conducted with the aim of establishing the type of internal parasites in catfish (Claris gariepinus) as well as the infection intensity. Ten catfish {Clarius gariepinus) specimens collected from the Gaborone Dam in Botswana were examined for internal parasites in August to November 2007. Eighty percent (80%) of these fish were found to be infected with third-stage larvae of Contracaecum spp in the abdominal cavity. The intensity of the infection was 14 to 250 worms per fish (mean intensity = 60.3 ± 9.70). The mean length of third-stage larvae was 14.25 ±3.28 to 35.88 ±4.96 with a range of 10 to 42min. No significant difference between host size and prevalence was established. Contracaecum species an anisakine nematode is potentially zoonotic. The public health implications of infected catfish arc discussed.
Article, BOJAAS, 2008
2008-01-01T00:00:00ZThe effect of blocking the angularis oculi and the facial veins on metabolism of Tswana goats
https://hdl.handle.net/13049/433
The effect of blocking the angularis oculi and the facial veins on metabolism of Tswana goats
Kamau, J. M.
The aim of this study was to compare changes in resting metabolism of Tswana goats as a result of diverting venous blood to and away from the cavernous sinus. Eighteen male yearlings were equally and randomly assigned to three groups: A non-operated control group (NOC), a facial vein blocked (BEV) group and an angularis oculi veins blocked group (BAOV). Resting metabolism was measured by an open circuit calorimetry system using a face mask. At the ambient temperatures (Ta) of 160C resting metabolic rate of the NOC group was significantly higher (p-0.014) than for the BOAV group but not significantly higher (p=0.303) than for the BFV group. At the Ta of 25 ° C resting metabolic rate of the NOC group was significantly higher (p=0.006) than for the BAOV group but not significantly higher (p=0.62) than for the BFV group. It appears that heat exchange at the carotid rate-cavernous sinus complex contributed significantly to the control of metabolic rate in the Tswana goats under non heat stressful conditions. Diverting blood from the facial veins into the jugular vein had no significant effect on resting metabolic rate under the same test conditions.
Article, BOJAAS, 2008
2008-01-01T00:00:00ZMechanical expression of oil from grated and preheated coconut meat
https://hdl.handle.net/13049/432
Mechanical expression of oil from grated and preheated coconut meat
Mwithiga, Gikuru; Fondo, Emanuel Chengo
Coconut oil was extracted from grated coconut using a hydraulic pressing method after the coconut gratings were preheated at heating medium air temperature in the range of 30-900C and heating durations ranging from zero to 45 minutes. Oil yields from the preheated copra indicated that adding distilled water to fresh grated copra in the ratio of 3:1 prior to heating the mixture in scaled plastic bags resulted in higher oil yield at all heating temperatures when compared to unheated copra. The oil yield also increased with increase in healing medium temperature up to 700C but declined with any further rise in heating medium temperature. Lowering the moisture content by drying copra in an air oven at 400C followed by oil extraction resulted in an increase in oil yield. It was noted that the oil yield increased with increase in the duration of preheating at all temperatures although the maximum increase was observed at heating temperatures of 50 and 600C. Grating the coconut to flakes of approximately 1mm thickness had the effect of increasing oil yield when compared to 2mm thick flakes.
Article, BOJAAS, 2008
2008-01-01T00:00:00ZEffect of spray nozzle type and crop canopy on spray deposition
https://hdl.handle.net/13049/431
Effect of spray nozzle type and crop canopy on spray deposition
Sanjika, T. M.; Jayasuriya, P. W.; Salokhe, V. M.
A study was carried out to investigate if the interaction between nozzle type and crop canopy has an effect on spray deposition and come up with ways of improving spray deposition during chemical applications to crops. The overall goal of the study was to optimize chemical use in crop production and minimize chemical pollution of the environment resulting from off-target spray deposition. Three nozzle types; disc-core hollow cone, disc-core full cone and extended range flat spray, and five crop canopy types; maize, soybean, tomato, mung bean and carrot were investigated. Two tracer solution application rates of 150 and 600 litres/ha were used in the study at a pump delivery pressure of 3 bars. Manganese sulphate monohydrate was used as a deposition tracer. Spray deposition on crop canopies was quantified using the Periodate Oxidation method. Results from the study indicated that nozzle-canopy interaction significantly affected spray deposition at 5% level of significance. It was also found out that spray deposition could be improved by up to 189% and 355% at tracer solution application rates of 150 and 600 litres/ha, respectively, if nozzles are selected based on crop canopy type.
Article, BOJAAS, 2008
2008-01-01T00:00:00Z