#growth parameters

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The demand for improved aquacultural practices is on constant increase to meet the demands of the teeming population of the human race at the lowest cost possible. The effects of combined vitamins C and E on the growth performance, catalase (CAT) and reduced glutathione (GSH) production levels in Clarias gariepinus fingerlings (10.00±0.00g) were evaluated for 12 week. 120 samples of the fish were assigned to 4 treatments thus: 00 (control), 200mg/L (T1), 300mg/L (T2) and 400mg/L (T3). The total length (TL), standard length (SL) and weight of the fish were determined weekly. The percentage weight gain (%W), specific growth rate (SGR) were also calculated. The kidneys, liver and gills were excised, homogenized in phosphate buffer; and then assayed for CAT and GSH every 4th week of the experiment. From the results, the TL and SL increased significantly with increase in the concentration of the combined vitamins especially in T2 and T3 much better than the control. The weight increased significantly from T1-T3 all through the 12 weeks with 120.88±28.75g as the highest, 1109%WG and SGR of 5.686g/day obtained in T3. The CAT and GSH in the kidneys, liver and gills decreased with increase in the concentrations of the combined vitamins and duration of the experiment with the control values significantly higher than all the treatments in most cases. The results from this research have shown significant improvements in growth and physiology of C. gariepinus and therefore, administration of these combined vitamins can serve as invaluable addition in catfish farming.

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Effects of intercropping on the performance of sorghum (cv Segaolane) and cowpeas in Botswana

Field experiment was conducted at Botswana University of Agriculture and Natural Resources (formerly Botswana College of Agriculture) from March-July 2016 to evaluate effects of intercropping on the performance of sorghum (segaolane) and cowpeas (black eye) in Botswana. The design of the experiment used was a complete randomized block design (CRBD) with five treatments including two controls (sole crops) each replicated three times. Growth parameters (plant height, number of leaves and canopy spread) and grain/seed weights were determined on five pre-determined plants from each plot and the collected data was subjected to analysis of variance (ANOVA). Generally, the number of leaves, plant height and canopy spread for both cowpeas and sorghum were non-significant (p˃0.05) across the treatments for the first six weeks after planting except for significant number of leaves for sorghum. The following weeks cowpeas and sorghum intercrop showed significant (p

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Stocking density of fish depicts the number of fish that are stocked supplied at first per unit area. It is one of the most significant factors in determining the production of a fish farm. The stocking fish at low density results in high production costs, low economic gain and inadequate utilization of space. Increasing stocking density may activate stress response which negatively affects growth parameters, survival, behavior, health, feeding of fish. Different metabolic pathways related to lipid, carbohydrate and protein metabolism are also affected by this stress. So, for good yield fish should be stocked at optimum level. Optimum stocking density is the level where the maximum yields are reached. Fish are considered as a potential source of animal protein and essential nutrients in human diet. Amino acids, the building blocks of protein, act as a precursor of many enzymes, hormones, neurotransmitters, nucleic acids and other molecules essential for life. High stocking density affects amino acid profile of fish. The enzymatic activities and synthetic rates of functional proteins that is associated with responses of stress, HSD that is used as a stressor may influence amino acid requirements. High stocking density significantly affects water quality, growth parameters and amino acid profile of fish and it may induce stress in fish and may have negative impact on fatty acid profile if environmental conditions are not suitable for fish.

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A biometric study was carried out on 121 specimens of Portunus validus caught by fishermen in April 2022, in Loango Bay. The objective of this study is to determine the morphometric parameters of this crab species. The results obtained show that the sex ratio in favor of males is equal to 1.47. The total carapace length of the specimens varies between 24.42 and 66.4, with an average of 37.03±12.14. The total width of the carapace of the specimens varies from 21.62 to 175.6 mm with an average of 83.66 ± 23.53 mm while the weight varies between 1.8 and 362 g with an average of 46.80 ± 5.28g. There are variables presenting significant differences with the sex: length of the hand of the large and small cheliped (LM1, LM2), the distance between the external ends of the orbits (Le), the lengths of the merus of the pairs of pereiopods (LMP2, LMP3, LMP4 and LMP5), the widths of the merus of the second (lMP2), third (lMP3) and fifth (lMP5) pairs of pereiopods and the weight. The other variables do not present significant differences at the α=0.05 threshold. The size-height relationships show a diminishing allometry except for the inter-orbital distance; this allometry also differs between males and females. The weight-height relationships show a lowering allometry regardless of the group considered.

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A biometric study was carried out on 121 specimens of Portunus validus caught by fishermen in April 2022, in Loango Bay. The objective of this study is to determine the morphometric parameters of this crab species. The results obtained show that the sex ratio in favor of males is equal to 1.47. The total carapace length of the specimens varies between 24.42 and 66.4, with an average of 37.03±12.14. The total width of the carapace of the specimens varies from 21.62 to 175.6 mm with an average of 83.66 ± 23.53 mm while the weight varies between 1.8 and 362 g with an average of 46.80 ± 5.28g. There are variables presenting significant differences with the sex: length of the hand of the large and small cheliped (LM1, LM2), the distance between the external ends of the orbits (Le), the lengths of the merus of the pairs of pereiopods (LMP2, LMP3, LMP4 and LMP5), the widths of the merus of the second (lMP2), third (lMP3) and fifth (lMP5) pairs of pereiopods and the weight. The other variables do not present significant differences at the α=0.05 threshold. The size-height relationships show a diminishing allometry except for the inter-orbital distance; this allometry also differs between males and females. The weight-height relationships show a lowering allometry regardless of the group considered.

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An attempt was made to find out the effect of gamma radiation on Panicum sumatrense. The seeds of little millet cv. ATL-1 and CO-2 were exposed to different doses of gamma rays, like 100, 200, 300, 400, 500, and 600 Gy. The seeds treated with gamma rays were sown in plastic pots with red soil to analyze the LD50 value and growth parameters. The lethal dose 50% value was observed at 400 Gy and 500 Gy for CV ATL-1 and CO-2, respectively. In both cultivars, all the growth parameters, such as percentage of germination, percentage of survival, shoot length, root length, fresh weight, and dry weight, showed a decreasing trend towards control with increasing doses of gamma rays, and the reduction was maximum at 600 Gy and minimum at 100 Gy. The cv.ATL-1 seedlings treated with gamma radiation were subjected to estimation of total protein content, and this protein content showed a decreasing trend compared to the control. The number of protein bands and kDa values of cv. ATL-1 were observed by using SDS-PAGE analysis. The kDa value of 132.8 was present only in 400, 500, and 600 Gy. The growth attributes of cultivar ATL-1 were unique compared to cultivar CO-2.