Browsing by Author "Mramba, Rosemary Peter"
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Item Activity patterns of African elephants in nutrient-rich and nutrient-poor savannas(Elsevier, 2019) Mramba, Rosemary Peter; Andreassen, Harry P.; Mlingi, Valeri; Skarpe, ChristinaThe Jarman-Bell principle states that small herbivores feed on the high quality forage in nutrient-rich, eutrophic savannas, whereas large herbivores tolerate the lower quality forage in nutrient poor, dystrophic, savannas. The African elephant, Loxodonta africana, is a large herbivore occurring in both savanna types, where it meets different quality and quantity of forage and different competition from small herbivores. Activities of elephants are comparatively well studied, but little emphasis has been on contrasting time allocation on different activities in eutrophic and in dystrophic savannas. We studied elephant activities in eutrophic Serengeti and dystrophic Mikumi, in Tanzania in order to explain differences between the savannas which differ in nutrient availability and herbivore densities. The two parks had similar, mean annual precipitation. We drove along all accessible roads in our study areas, and once an individual or a group of elephants was sighted the car was stopped for observation. We used group activity scan sampling methods to record number of individuals grazing, walking, resting, browsing, interacting with other group members or vigilant in a group. We also recorded group type, group size, and habitat. The study revealed that activity patterns of elephants differed between the eutrophic and the dystrophic savanna, between females and males, and between the wet and the dry season. Grazing was a dominant activity in both sites, particularly in the wet season, when nutritious grasses were available. There was more browsing in the eutrophic Serengeti compared to the dystrophic Mikumi and in bachelor compared to family groups, probably due to differences in availability of grass and browse, and in palatability of plant material between the sites. Resting was affected by interaction effect between site and season, where proportions of individuals resting in a group was higher in Mikumi in the dry season and in Serengeti in the wet. Walking was affected by group type, where bachelor groups walked more than family groups, probably searching for estrous females, and by interaction between season and site, where elephants walked more in Serengeti in the wet season and in Mikumi in the dry. The dry season has limited forage quantity and quality and shortage of water, thus animals face a tradeoff between resting to save energy and walking to search for water and food. We conclude that, the differences recorded between the sites might be attributed to differences in quality and quantity of grazing and browsing, as well as to differences in nutritional and reproductive demands between females and males.Item Browsing behaviour of impala, Aepyceros melampus in two contrasting savannas(Elsevier, 2021) Mramba, Rosemary PeterImpala are medium-sized antelopes, widely distributed throughout East and Southern Africa. They consume grasses in the wet season, switching to browsing in the dry season. African savannas are classified into arid-eutrophic and moist-dystrophic. The arid-eutrophic savannas have fertile soils which support plant biomass of high nutritive value, utilised by small and mediumsized herbivores. The moist-dystrophic savannas have nutrient-poor soils and high plant biomass of relatively low nutritive values, utilised by large-bodied herbivores. Impala occur in both savannas, though more abundant in the arid-eutrophic savannas. I studied browsing behaviour of impala in Mikumi National Park, a moist-dystrophic savanna, and Serengeti National Park, an arid-eutrophic savanna. A car was driven in all access roads in the Parks during the wet and the dry season. The car was stopped for recording whenever impala were sighted browsing within 50 m from the road. I recorded tree species browsed, browsing height, number of bites, and habitat type. The study showed differences between the seasons and the savannas. The animals took more bites during the dry season compared to the wet. Biting rate was higher during the dry season and when spineless trees were utilised. Small and large leaves reduced biting rate while medium size leaves promoted biting rate. The impala frequently browsed at head level in both savannas, however variations between the savannas were observed during the wet season. The differences in forage quality and quantity between the savannas and the seasons, and in herbivore community between the savannas are likely to attribute the results.Item Determinants of fish catch and post-harvest fish spoilage in small-scale marine fisheries in the Bagamoyo district, Tanzania(Elsevier, 2022) Mramba, Rosemary Peter; Mkude, Kelvin EmmanuelThe fisheries sector of Tanzania is dominated by small-scale fishers who produce up to 95% of the total amount of fish caught in the country. The small-scale fisheries are constrained by inadequate infrastructure, including a lack of capacity for processing and cold storage facilities, poor transportation and fishing tools that increase postharvest losses. Small-scale fishers lack sufficient capital and skills to invest in modern fishing technologies. Additionally, social-demographic aspects of the fishers, such as education level, gender, age, fishing experience and training influence access to fishing resources and capital, leading to variation in fish catch and post-harvest losses. Thus, this study examined factors that influence fish catch and spoilage in small-scale fisheries in the Bagamoyo District, Tanzania. Forty randomly selected fishers from the Mlingotini fishing village were interviewed. The results show that after spending an average of 11 h per fishing session, the fishers catch an average of 18.5 kg of fish. The amount of fish captured differed with fishing experience, age and sex of the fisher, education level of the fisher, and the time spent selling the captured fish. On average, 10% of the weight of the fish captured per fishing session spoils. The level of spoilage varied according to the fisher's age and sex, education level, fishing experience, length of fishing session, and fishing gear used. Provision of training related to fish processing and handling and improvement of cold storage and transport facilities are recommended to reduce spoilage.Item The role of feeds in the transmission of chicken pathogens in Dodoma Urban District, Tanzania(Elsevier, 2023) Mramba, Rosemary PeterChicken production is an important economic activity in Tanzania. Indigenous chickens are kept in rural areas, while exotic breeds are kept in urban areas. Due to their high productivity, exotic breeds are becoming important sources of protein in fast-growing cities. Dodoma is one of the cities growing very fast in Tanzania. As a result, production of layers and broilers has increased dramatically. However, diseases remain the major challenge to chicken production despite the efforts of livestock officers to educate people on good management practices. This has made farmers think that feeds may be the source of pathogens. The study's objectives were thus to identify the major diseases affecting broiler and layer chickens in the Dodoma urban district, as well as the potential role of feeds in pathogen transmission to chickens. A household survey was conducted to identify common diseases affecting chickens in the study area. Thereafter, locally prepared feed samples were collected from twenty shops available in the district to determine the presence of Salmonella and Eimeria parasites. The presence of Eimeria parasites in the feeds was determined by raising day-old chicks in a sterile environment for three weeks while feeding them the feed samples collected. Fecal samples from the chicks were analyzed for the presence of Eimeria parasites. Salmonella contamination of the feed samples was determined in the laboratory through the culture method. The study found that coccidiosis, Newcastle disease, fowl typhoid, infectious bursal disease, and colibacillosis are the main diseases affecting chickens in the district. After three weeks of rearing, three out of fifteen chicks developed coccidiosis. In addition, about 31.1% of the feed samples showed the presence of Salmonella spp. The prevalence of Salmonella was highest in limestone (53.3%), followed by fishmeal (26.7%), and maize bran (13.3%). It has been concluded that feeds are potential carriers of pathogens. To reduce economic losses and the continuous use of drugs in chicken production, health authorities should assess the microbial quality of poultry feeds.Item The role of feeds in the transmission of chicken pathogens in Dodoma Urban District, Tanzania(Elsevier, 2023) Mramba, Rosemary PeterChicken production is an important economic activity in Tanzania. Indigenous chickens are kept in rural areas, while exotic breeds are kept in urban areas. Due to their high productivity, exotic breeds are becoming important sources of protein in fast-growing cities. Dodoma is one of the cities growing very fast in Tanzania. As a result, production of layers and broilers has increased dramatically. However, diseases remain the major challenge to chicken production despite the efforts of livestock officers to educate people on good management practices. This has made farmers think that feeds may be the source of pathogens. The study’s objectives were thus to identify the major diseases affecting broiler and layer chickens in the Dodoma urban district, as well as the potential role of feeds in pathogen transmission to chickens. A household survey was conducted to identify common diseases affecting chickens in the study area. Thereafter, locally prepared feed samples were collected from twenty shops available in the district to determine the presence of Salmonella and Eimeria parasites. The presence of Eimeria parasites in the feeds was determined by raising day-old chicks in a sterile environment for 3 wk while feeding them the feed samples collected. Fecal samples from the chicks were analyzed for the presence of Eimeria parasites. Salmonella contamination of the feed samples was determined in the laboratory through the culture method. The study found that coccidiosis, Newcastle disease, fowl typhoid, infectious bursal disease, and colibacillosis are the main diseases affecting chickens in the district. After 3 wk of rearing, 3 out of 15 chicks developed coccidiosis. In addition, about 31.1% of the feed samples showed the presence of Salmonella spp. The prevalence of Salmonella was highest in limestone (53.3%), followed by fishmeal (26.7%), and maize bran (13.3%). It has been concluded that feeds are potential carriers of pathogens. To reduce economic losses and the continuous use of drugs in chicken production, health authorities should assess the microbial quality of poultry feeds.Item Sexual segregation in foraging giraffe(Elsevier, 2017) Mramba, Rosemary Peter; Mahenya, Obeid; Siyaya, Annetjie; Mathisen, Karen Marie; Andreassen, Harry Peter; Skarpe, ChristinaSexual segregation in giraffe is known to vary between savannas. In this study, we compared sexual segregation in giraffe in one nutrient-rich savanna, the Serengeti National Park, one nutrient-poor, Mikumi National Park, and one medium rich savanna, Arusha National Park, (from here on referred to just by name) based on effects of sexual size dimorphism and related hypotheses. Data were collected in the wet and dry seasons, by driving road transects and making visual observations of browsing giraffe. Additional data were collected from literature (plant chemistry; mammal communities). There was a noticeable difference in browsing by females and males and in browsing between the three savannas. Females browsed a higher diversity of tree species in Serengeti whereas males browsed a higher diversity in Arusha, while the diversity of species browsed in Mikumi was high and about the same in both sexes. Females selected for high concentrations of nitrogen and low concentrations of tannins and phenolics compared to males in Serengeti but selection in Mikumi was more complex. Males browsed higher in the canopy than females in all sites, but the browsing height was generally higher in Serengeti than Mikumi and Arusha. Season had an effect on the browsing height independent of sex in Mikumi, where giraffes browsed higher in the dry season compared to the wet season. Males spent more time browsing per tree compared to females in all three sites; however, browsing time in Mikumi was also affected by season, where giraffes had longer browsing bouts in the wet season compared to the dry season. We suggest that sexual differences in forage requirement and in foraging interacts with differences in tree chemistry and in competing herbivore communities between nutrient rich and nutrient poor savanna in shaping the sexual segregation.Item The status and challenges of aquaculture development in Dodoma, a semi-arid region in Tanzania(Springer, 2022) Mramba, Rosemary Peter; Kahindi, Emmanuel JacobDemand for fish is growing rapidly in Tanzania due to population growth and rising incomes. However, as fewer wild fish are being caught, there is a gap in fish supply. Aquaculture is a viable alternative source to meet the gap in fish demand. Tanzania has the perfect climate and land for fish farming. Aquaculture in fresh and salt water has grown quickly, yet the potential is not being fully tapped. Thus, the study assessed the growth of aquaculture in Dodoma, a rapidly developing semi-arid region of Tanzania, in order to determine its potential, challenges, and solutions. Thirty-six fish farmers from Dodoma urban district were visited and interviewed. The interviews gathered information about management practices, fish yield, and challenges. The findings show that aquaculture in the region began around 9 years ago, when the region began to expand. The aquaculture includes small-scale pond farming of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus). Fish yield was about 1925 kg ha−1 per culture cycle, and fish customers are definitely available. The main challenges were limited supply and high prices of fish feed and seeds, and limited water supply. Use of commercial feed, pond fertilisation, access to extension services, and ownership of a borehole were related to high fish yields in both species. Expansion of aquaculture in the region is possible with the improvement of extension services and training of farmers in proper breeding, feeding, and water management. To decrease water demands, integrated aquaculture, water recycling, and aquaponics should be encouraged.