This study investigated the role of fish in addressing food and nutrition security challenges in ... more This study investigated the role of fish in addressing food and nutrition security challenges in Southern Africa, focusing on 10 countries including Angola, Zambia,
This study investigated the role of fish in addressing food and nutrition security challenges in ... more This study investigated the role of fish in addressing food and nutrition security challenges in Southern Africa, focusing on 10 countries including Angola, Zambia,
As a land-locked country in Southern Africa, Zambia is rich in natural resources suitable for fis... more As a land-locked country in Southern Africa, Zambia is rich in natural resources suitable for fish production. However, aquaculture is still in its infancy with enormous potential as most of Zambia's fish now comes from capture fisheries. The aim of this study was to review the recent progress, status, challenges, and opportunities in Zambia's aquaculture industry while drawing some lessons from China's aquaculture experience, focusing on policy instruments, external support, quality seeds, and the investment environment for possible adaptation. To achieve this, we reviewed the existing literature about aquaculture in Zambia. This paper starts by reviewing the overall fishery sector's developments based on the analysis of relevant statistics over decades before narrowing down to the aquaculture sub-sector. The review shows that aquaculture production has continued to expand significantly and will soon play a leading role in food and nutrition security in Zambia. However, the industry still faces major challenges relating to investments, science and technology, fish seed and feed, and an underdeveloped value chain besides the increasing demand for fish products. Nevertheless, great potential still exists to further develop the aquaculture sub-sector and meet the ever-growing demand for fish products caused mainly by the rapid population increase.
Aquaculture plays a critical role in Zambia's food and nutrition security. However, aquaculture i... more Aquaculture plays a critical role in Zambia's food and nutrition security. However, aquaculture is highly vulnerable to the e ects of a changing climate which can lead to economic losses, and food and nutrition insecurity. In this study, we investigated the perceived e ects of climate change on aquaculture production in Zambia, vulnerability factors, and adaptation strategies. We used semistructured and structured questionnaires to collect data from aquaculture producers in all provinces across the country. Results revealed high (over %) awareness of climate change, primarily attributed to literacy levels and access to media. Producers perceived occurrence of climate-related changes such as rising temperature, altered rainfall patterns, cyclones frequency, and disease outbreaks, impacting production costs. Generally, the results indicate a high to medium perception of rising temperature and increased frequency of flooding and droughts across the country. Although rising temperature did not appear to a ect aquaculture production cost, the frequency of droughts, floods, cyclones, and disease outbreaks showed a significant association with production costs. Identified vulnerability factors include reliance on a limited range of fish species, absence of insurance coverage, and low adoption of adaptation practices. Vulnerability levels vary across regions, with provinces in agroecological Frontiers in Sustainable Food Systems frontiersin.org Maulu et al.. /fsufs.. zone I (Eastern, Lusaka, Southern, and Western) showing higher vulnerability. Despite this, many producers aren't implementing adaptation measures due to financial limitations, species diversity constraints, and insu cient knowledge of alternative economic pursuits. Main adaptation strategies involve livelihood diversification and adjustments in fish cultivation periods and infrastructure. To foster aquaculture sustainability amid climate change, critical interventions such as farm insurance, research diversification in aquaculture species, and enhancing producer resilience are necessary.
This study investigated the application of anaesthetics in 23 private and government-owned hatche... more This study investigated the application of anaesthetics in 23 private and government-owned hatcheries in 10 provinces of Zambia. The study employed both qualitative and quantitative research designs and used a structured questionnaire to collect data from the respondents. The results showed that most hatcheries (65%) were not using anaesthetics in handling fish and all (100%) that were using anaesthetics (35%) used clove powder as the only type. Most respondents (61%) were not sure or did not have information about the availability of the anaesthetic substances in their localities while only 26% reported wider availability but 13% had a divergent claim. The mortality rate for fingerlings in hatcheries that applied anaesthetics ranged between 15–30% with consistently high demand while those that did not use anaesthetics reported mortality rates of more than 50% and had low demand. The majority of the respondents (53%) had received training up to certificate level, followed by those who had attained up to a diploma qualification (27%) while those that attained up to a degree (13%) and general skills (7%) levels were in the minority. Furthermore, most respondents (35%) did not know the importance of fish anaesthetics. We conclude that the use of fish anaesthetics in Zambian hatcheries is very low and could partly be the cause of high fingerling mortalities, and there is an urgent need to address the situation.
Aquaculture is a significant industry in food production, and its contribution to food and nutrit... more Aquaculture is a significant industry in food production, and its contribution to food and nutrition security is well acknowledged. Zambia’s aquaculture production has continued to increase significantly, thus playing a key role in supplying animal protein sources for human consumption. However, recent estimates show that 75% of the national aquaculture production comes from large-scale commercial producers despite being by far the minority while the majority of small-scale producers contribute the remaining 25% of the total annual production. This low production by small-scale producers is attributed to insufficient financial resources, poor management and utilization of farm resources, lack of access to competitive markets, and more recently a changing climate. In this research, we examine the viability of integrated agriculture-aquaculture (IAA) as a means for small-scale producers in Zambia to boost their aquaculture output despite the numerous obstacles they face. In addition, ...
Aquaculture is a significant industry in food production, and its contribution to food and nutrit... more Aquaculture is a significant industry in food production, and its contribution to food and nutrition security is well acknowledged. Zambia’s aquaculture production has continued to increase significantly, thus playing a key role in supplying animal protein sources for human consumption. However, recent estimates show that 75% of the national aquaculture production comes from large-scale commercial producers despite being by far the minority while the majority of small-scale producers contribute the remaining 25% of the total annual production. This low production by small-scale producers is attributed to insufficient financial resources, poor management and utilization of farm resources, lack of access to competitive markets, and more recently a changing climate. In this research, we examine the viability of integrated agriculture-aquaculture (IAA) as a means for small-scale producers in Zambia to boost their aquaculture output despite the numerous obstacles they face. In addition, ...
Extension programs in rural communities play a critical role in linking farmers and other actors ... more Extension programs in rural communities play a critical role in linking farmers and other actors in rural developmental agenda. The relevance of these programs in agriculture is largely dependent on their ability to meet farmers' needs since they are the stakeholders at the grassroots. This paper aimed to review studies on enhancing the role of rural agricultural extension programs in poverty alleviation. Various approaches and tools used in rural extension program delivery have been discussed, and ways in which their contribution to poverty alleviation can be enhanced have been highlighted. Extension programs have undergone many changes throughout the years in response to farmers' changing needs as well as the market they operate in. Therefore, there is no "one-size-fits-all" approach recommended for effective service delivery and outcome due to different farmer needs that are affected by their geographical location, social and economic structures. We conclude that rural extension programs can provide a sustainable solution to Sahya Maulu ABOUT THE AUTHORS Sahya Maulu is a board chairperson at Centre for Innovative Approach Zambia (CIAZ). His research focuses on agriculture, fisheries, aquaculture, rural development, and climate Change. Oliver Jolezya Hasimuna is an Aquaculture Research Officer at the Zambian Department of Fisheries. His research interest includes Aquatic Ecology, fish anesthetics, fish nutrition, fish breeding and genetics, aquatic animal diseases, and fisheries management Bornwell Mutale is a master's degree student at Ocean University of China. His research interests include agriculture and fisheries economics, rural development through agriculture, and environmental economics. Joseph Mphande is a Fisheries Officer at the Zambian Department of Fisheries. His research interests are in fisheries management, Morphometrics and meristic, Fish diseases, genetics, Climate change, microplastics and their impacts on aquatic biota Enock Siankwilimba is a co-founder and agricultural diversification manager at Musika Zambia. His research focuses on agricultural market systems development, livestock and crop business models, climate change, value chain development and rural development.
Journal of Aquaculture Research and Development, 2019
The application of science and technology developments in aquaculture is very crucial for the sus... more The application of science and technology developments in aquaculture is very crucial for the sustainable development of the industry. This paper provides an overview of the current developments in science and technology used in Zambia’s aquaculture industry. Various developments particularly in aquacultural species and culture models, aquaculture production systems, fish feeds and nutrition, water environmental management, and fish health and disease management have been discussed. While some breakthroughs in science and technology have been presented, the review has indicated that the country’s aquaculture industry is still lagging behind in some critical areas as the majority of producers are still using traditional technologies which have made it difficult for them to make significant contributions to fish production. As a result of this lag and other reasons, the country has witnessed an unprecedented importation of fish to meet the deficit and the ever-increasing demand. There...
Abstract 8 weeks rearing trial was designed to estimate the dietary lysine requirement, and evalu... more Abstract 8 weeks rearing trial was designed to estimate the dietary lysine requirement, and evaluate the effects of dietary lysine on glycometabolism and lipid metabolism of grass carp fry. Six practical diets were prepared to feed 720 fish (initial weight 0.36 ± 0.00 g) with graded lysine levels (1.44%, 1.79%, 1.97%, 2.44%, 2.56% and 2.87%, dry diet). The results displayed that the final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) were significantly improved by 2.44% dietary lysine, the same as feed intake (FI) and feed conversion ratio (FCR), compared with those of the control group (1.44% dietary lysine). Whole-body lipid contents diminished with raising dietary lysine levels from 1.44% to 2.44% and thereafter the content increased. Regarding glycometabolism, compared to the control diet, the 2.44% dietary lysine level significantly improved glycolysis by increasing glucokinase (GK) and pyruvate kinase (PK) mRNA levels, meanwhile the 2.87% dietary lysine level promoted gluconeogenesis by significantly increasing phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) mRNA levels. Glycogen synthase (GS) mRNA levels were independent of dietary treatment. For the lipolysis pathway, the 2.44% dietary lysine level caused the upregulation of hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL) and carnitine palmitoyl transferase-1 (CPT1) mRNA levels in the PPAR signaling pathway. Like the fatty acid synthase (FAS), acetyl-CoA carboxylase-1 (ACC1) and stearyl-CoA desaturase (SCD), the relative mRNA expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) related to lipid synthesis in the PPAR signaling pathway, was not remarkably influenced by dietary lysine levels. Furthermore, sterol-regulatory element binding protein-1 (SREBP1) mRNA levels in the intestine were not clearly affected among all the treatments. According to the broken-line regression analysis, based on the SGR and FCR, the optimum requirements of grass carp fry for dietary lysine were 2.39% and 2.13% of diet (6.34% and 5.65% of dietary protein), respectively. Overall, appropriate dietary lysine levels (2.44%) could improve the growth performance, reduce the whole-body lipid, promote glycolysis and lipolysis.
Facilitative glucose transporter 4 (GLUT4) plays a central role in mediating insulin function to ... more Facilitative glucose transporter 4 (GLUT4) plays a central role in mediating insulin function to increase glucose uptake in glucose metabolism homeostasis. In this study, the function and localization of GLUT4 in blunt snout bream (Megalobrama amblycephala) were first investigated, and then, the response measured as carbohydrate level, was analyzed. The results showed that the cDNA sequence of GLUT4 in blunt snout bream (MaGLUT4, GenBank accession no: MT447093) was 2868 bp in length, and the corresponding mRNA contained a 5-UTR region of 513 bp and a 3-UTR region of 837 bp. MaGLUT4 had an open reading frame of 1518 bp and was encoded by 505 amino acids. Its theoretical isoelectric point and molecular weight was 6.41 and 55.47 kDa, respectively. A comparison of these characteristics with BLASTP results from the NCBI database showed that MaGLUT4 had the highest homology with Cypriniformes fish, with MaGLUT4 and GLUT4 of other Cypriniformes clustered in the phylogenetic tree with other GLUT1-4 amino acid sequences. Compared with the results from the homo_sapiens and mus_musculus data sets, some mutations were observed in the GLUT4 amino acid sequence of these aquatic animals, including an FQQI mutation to FQQL, LL mutation to MM, and TELEY mutation to TELDY. MaGLUT4 was constitutively expressed in the muscle, intestine, and liver, with the highest mRNA level observed in muscle. Furthermore, the predicted tertiary structure and results of immunohistochemical staining showed that MaGLUT4 was a transmembrane protein primarily located in the plasma membrane, where it accounts for 60.9% of the total expressed, according to an analysis of subcellular localization. Blood glucose level peaked within 1 h, and the insulin level peaked at 6 h, while the mRNA and protein levels of GLUT4 showed an upward trend with an increase in feeding time and decreased sharply after 12 h. These results confirmed that MaGLUT4 was mainly distributed in muscles and crosses the cell membrane. The changes in the insulin,
Fish is an extremely perishable food product which requires proper handling soon after harvest. T... more Fish is an extremely perishable food product which requires proper handling soon after harvest. The present study was aimed at assessing post-harvest fish losses and preservation practices in Siavonga district, Southern Zambia. Structured and semi-structured questionnaires were used to collect data on post-harvest fish losses and preservation practices from aquaculture producers, artisanal, and commercial fishers. All the fishers who landed on the lakeshore were interviewed, while aquaculture producers were randomly selected based on the information provided by the local department of fisheries. The results of the study revealed that all the fishers experienced post-harvest fish losses at varying degrees with those losing up to 10% of the total catch being in the majority. In contrast, aquaculture producers did not report any post-harvest fish losses. Most aquaculture producers commonly used chilling as preservation practice contrary to artisanal and commercial fishers who commonly ...
Abstract Cage aquaculture is among the recent innovations that have attracted great attention in ... more Abstract Cage aquaculture is among the recent innovations that have attracted great attention in fish production in most African countries. In Zambia, cage aquaculture has recorded significant growth to even emerge as the largest contributor to the total national aquaculture production annually. Our study was aimed at assessing cage aquaculture production in Siavonga district of Zambia. We targeted the aquaculture and feed manufacturing companies, their production, challenges, and opportunities. This study revealed that there were five main aquaculture production companies with fish cages ranging from 96 m3 to 135,534 m3 in size. Oreochromis niloticus was found to be the only cultured species. Lack of quality fish seed and feed were the major challenges faced by the aquaculture production companies in Siavonga district. The study further revealed that there were two major aquafeed manufacturing companies within the district with a production capacity ranging from 50 tons to 200 tons per day. Lack of readily available raw material for feed making was the major challenge facing the aquafeed manufacturing companies. There are huge potentials for cage aquaculture in Siavonga district, which can significantly contribute to the nation's aquaculture production. These include the availability of large fish feed manufacturing companies and huge water resources.
Extension programs in rural communities play a critical role in linking farmers and other actors ... more Extension programs in rural communities play a critical role in linking farmers and other actors in rural developmental agenda. The relevance of these programs in agriculture is largely dependent on their ability to meet farmers' needs since they are the stakeholders at the grassroots. This paper aimed to review studies on enhancing the role of rural agricultural extension programs in poverty alleviation. Various approaches and tools used in rural extension program delivery have been discussed, and ways in which their contribution to poverty alleviation can be enhanced have been highlighted. Extension programs have undergone many changes throughout the years in response to farmers' changing needs as well as the market they operate in. Therefore, there is no "one-size-fits-all" approach recommended for effective service delivery and outcome due to different farmer needs that are affected by their geographical location, social and economic structures. We conclude that rural extension programs can provide a sustainable solution to Sahya Maulu ABOUT THE AUTHORS Sahya Maulu is a board chairperson at Centre for Innovative Approach Zambia (CIAZ). His research focuses on agriculture, fisheries, aquaculture, rural development, and climate Change. Oliver Jolezya Hasimuna is an Aquaculture Research Officer at the Zambian Department of Fisheries. His research interest includes Aquatic Ecology, fish anesthetics, fish nutrition, fish breeding and genetics, aquatic animal diseases, and fisheries management Bornwell Mutale is a master's degree student at Ocean University of China. His research interests include agriculture and fisheries economics, rural development through agriculture, and environmental economics. Joseph Mphande is a Fisheries Officer at the Zambian Department of Fisheries. His research interests are in fisheries management, Morphometrics and meristic, Fish diseases, genetics, Climate change, microplastics and their impacts on aquatic biota Enock Siankwilimba is a co-founder and agricultural diversification manager at Musika Zambia. His research focuses on agricultural market systems development, livestock and crop business models, climate change, value chain development and rural development.
This study investigated the role of fish in addressing food and nutrition security challenges in ... more This study investigated the role of fish in addressing food and nutrition security challenges in Southern Africa, focusing on 10 countries including Angola, Zambia,
This study investigated the role of fish in addressing food and nutrition security challenges in ... more This study investigated the role of fish in addressing food and nutrition security challenges in Southern Africa, focusing on 10 countries including Angola, Zambia,
As a land-locked country in Southern Africa, Zambia is rich in natural resources suitable for fis... more As a land-locked country in Southern Africa, Zambia is rich in natural resources suitable for fish production. However, aquaculture is still in its infancy with enormous potential as most of Zambia's fish now comes from capture fisheries. The aim of this study was to review the recent progress, status, challenges, and opportunities in Zambia's aquaculture industry while drawing some lessons from China's aquaculture experience, focusing on policy instruments, external support, quality seeds, and the investment environment for possible adaptation. To achieve this, we reviewed the existing literature about aquaculture in Zambia. This paper starts by reviewing the overall fishery sector's developments based on the analysis of relevant statistics over decades before narrowing down to the aquaculture sub-sector. The review shows that aquaculture production has continued to expand significantly and will soon play a leading role in food and nutrition security in Zambia. However, the industry still faces major challenges relating to investments, science and technology, fish seed and feed, and an underdeveloped value chain besides the increasing demand for fish products. Nevertheless, great potential still exists to further develop the aquaculture sub-sector and meet the ever-growing demand for fish products caused mainly by the rapid population increase.
Aquaculture plays a critical role in Zambia's food and nutrition security. However, aquaculture i... more Aquaculture plays a critical role in Zambia's food and nutrition security. However, aquaculture is highly vulnerable to the e ects of a changing climate which can lead to economic losses, and food and nutrition insecurity. In this study, we investigated the perceived e ects of climate change on aquaculture production in Zambia, vulnerability factors, and adaptation strategies. We used semistructured and structured questionnaires to collect data from aquaculture producers in all provinces across the country. Results revealed high (over %) awareness of climate change, primarily attributed to literacy levels and access to media. Producers perceived occurrence of climate-related changes such as rising temperature, altered rainfall patterns, cyclones frequency, and disease outbreaks, impacting production costs. Generally, the results indicate a high to medium perception of rising temperature and increased frequency of flooding and droughts across the country. Although rising temperature did not appear to a ect aquaculture production cost, the frequency of droughts, floods, cyclones, and disease outbreaks showed a significant association with production costs. Identified vulnerability factors include reliance on a limited range of fish species, absence of insurance coverage, and low adoption of adaptation practices. Vulnerability levels vary across regions, with provinces in agroecological Frontiers in Sustainable Food Systems frontiersin.org Maulu et al.. /fsufs.. zone I (Eastern, Lusaka, Southern, and Western) showing higher vulnerability. Despite this, many producers aren't implementing adaptation measures due to financial limitations, species diversity constraints, and insu cient knowledge of alternative economic pursuits. Main adaptation strategies involve livelihood diversification and adjustments in fish cultivation periods and infrastructure. To foster aquaculture sustainability amid climate change, critical interventions such as farm insurance, research diversification in aquaculture species, and enhancing producer resilience are necessary.
This study investigated the application of anaesthetics in 23 private and government-owned hatche... more This study investigated the application of anaesthetics in 23 private and government-owned hatcheries in 10 provinces of Zambia. The study employed both qualitative and quantitative research designs and used a structured questionnaire to collect data from the respondents. The results showed that most hatcheries (65%) were not using anaesthetics in handling fish and all (100%) that were using anaesthetics (35%) used clove powder as the only type. Most respondents (61%) were not sure or did not have information about the availability of the anaesthetic substances in their localities while only 26% reported wider availability but 13% had a divergent claim. The mortality rate for fingerlings in hatcheries that applied anaesthetics ranged between 15–30% with consistently high demand while those that did not use anaesthetics reported mortality rates of more than 50% and had low demand. The majority of the respondents (53%) had received training up to certificate level, followed by those who had attained up to a diploma qualification (27%) while those that attained up to a degree (13%) and general skills (7%) levels were in the minority. Furthermore, most respondents (35%) did not know the importance of fish anaesthetics. We conclude that the use of fish anaesthetics in Zambian hatcheries is very low and could partly be the cause of high fingerling mortalities, and there is an urgent need to address the situation.
Aquaculture is a significant industry in food production, and its contribution to food and nutrit... more Aquaculture is a significant industry in food production, and its contribution to food and nutrition security is well acknowledged. Zambia’s aquaculture production has continued to increase significantly, thus playing a key role in supplying animal protein sources for human consumption. However, recent estimates show that 75% of the national aquaculture production comes from large-scale commercial producers despite being by far the minority while the majority of small-scale producers contribute the remaining 25% of the total annual production. This low production by small-scale producers is attributed to insufficient financial resources, poor management and utilization of farm resources, lack of access to competitive markets, and more recently a changing climate. In this research, we examine the viability of integrated agriculture-aquaculture (IAA) as a means for small-scale producers in Zambia to boost their aquaculture output despite the numerous obstacles they face. In addition, ...
Aquaculture is a significant industry in food production, and its contribution to food and nutrit... more Aquaculture is a significant industry in food production, and its contribution to food and nutrition security is well acknowledged. Zambia’s aquaculture production has continued to increase significantly, thus playing a key role in supplying animal protein sources for human consumption. However, recent estimates show that 75% of the national aquaculture production comes from large-scale commercial producers despite being by far the minority while the majority of small-scale producers contribute the remaining 25% of the total annual production. This low production by small-scale producers is attributed to insufficient financial resources, poor management and utilization of farm resources, lack of access to competitive markets, and more recently a changing climate. In this research, we examine the viability of integrated agriculture-aquaculture (IAA) as a means for small-scale producers in Zambia to boost their aquaculture output despite the numerous obstacles they face. In addition, ...
Extension programs in rural communities play a critical role in linking farmers and other actors ... more Extension programs in rural communities play a critical role in linking farmers and other actors in rural developmental agenda. The relevance of these programs in agriculture is largely dependent on their ability to meet farmers' needs since they are the stakeholders at the grassroots. This paper aimed to review studies on enhancing the role of rural agricultural extension programs in poverty alleviation. Various approaches and tools used in rural extension program delivery have been discussed, and ways in which their contribution to poverty alleviation can be enhanced have been highlighted. Extension programs have undergone many changes throughout the years in response to farmers' changing needs as well as the market they operate in. Therefore, there is no "one-size-fits-all" approach recommended for effective service delivery and outcome due to different farmer needs that are affected by their geographical location, social and economic structures. We conclude that rural extension programs can provide a sustainable solution to Sahya Maulu ABOUT THE AUTHORS Sahya Maulu is a board chairperson at Centre for Innovative Approach Zambia (CIAZ). His research focuses on agriculture, fisheries, aquaculture, rural development, and climate Change. Oliver Jolezya Hasimuna is an Aquaculture Research Officer at the Zambian Department of Fisheries. His research interest includes Aquatic Ecology, fish anesthetics, fish nutrition, fish breeding and genetics, aquatic animal diseases, and fisheries management Bornwell Mutale is a master's degree student at Ocean University of China. His research interests include agriculture and fisheries economics, rural development through agriculture, and environmental economics. Joseph Mphande is a Fisheries Officer at the Zambian Department of Fisheries. His research interests are in fisheries management, Morphometrics and meristic, Fish diseases, genetics, Climate change, microplastics and their impacts on aquatic biota Enock Siankwilimba is a co-founder and agricultural diversification manager at Musika Zambia. His research focuses on agricultural market systems development, livestock and crop business models, climate change, value chain development and rural development.
Journal of Aquaculture Research and Development, 2019
The application of science and technology developments in aquaculture is very crucial for the sus... more The application of science and technology developments in aquaculture is very crucial for the sustainable development of the industry. This paper provides an overview of the current developments in science and technology used in Zambia’s aquaculture industry. Various developments particularly in aquacultural species and culture models, aquaculture production systems, fish feeds and nutrition, water environmental management, and fish health and disease management have been discussed. While some breakthroughs in science and technology have been presented, the review has indicated that the country’s aquaculture industry is still lagging behind in some critical areas as the majority of producers are still using traditional technologies which have made it difficult for them to make significant contributions to fish production. As a result of this lag and other reasons, the country has witnessed an unprecedented importation of fish to meet the deficit and the ever-increasing demand. There...
Abstract 8 weeks rearing trial was designed to estimate the dietary lysine requirement, and evalu... more Abstract 8 weeks rearing trial was designed to estimate the dietary lysine requirement, and evaluate the effects of dietary lysine on glycometabolism and lipid metabolism of grass carp fry. Six practical diets were prepared to feed 720 fish (initial weight 0.36 ± 0.00 g) with graded lysine levels (1.44%, 1.79%, 1.97%, 2.44%, 2.56% and 2.87%, dry diet). The results displayed that the final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) were significantly improved by 2.44% dietary lysine, the same as feed intake (FI) and feed conversion ratio (FCR), compared with those of the control group (1.44% dietary lysine). Whole-body lipid contents diminished with raising dietary lysine levels from 1.44% to 2.44% and thereafter the content increased. Regarding glycometabolism, compared to the control diet, the 2.44% dietary lysine level significantly improved glycolysis by increasing glucokinase (GK) and pyruvate kinase (PK) mRNA levels, meanwhile the 2.87% dietary lysine level promoted gluconeogenesis by significantly increasing phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) mRNA levels. Glycogen synthase (GS) mRNA levels were independent of dietary treatment. For the lipolysis pathway, the 2.44% dietary lysine level caused the upregulation of hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL) and carnitine palmitoyl transferase-1 (CPT1) mRNA levels in the PPAR signaling pathway. Like the fatty acid synthase (FAS), acetyl-CoA carboxylase-1 (ACC1) and stearyl-CoA desaturase (SCD), the relative mRNA expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) related to lipid synthesis in the PPAR signaling pathway, was not remarkably influenced by dietary lysine levels. Furthermore, sterol-regulatory element binding protein-1 (SREBP1) mRNA levels in the intestine were not clearly affected among all the treatments. According to the broken-line regression analysis, based on the SGR and FCR, the optimum requirements of grass carp fry for dietary lysine were 2.39% and 2.13% of diet (6.34% and 5.65% of dietary protein), respectively. Overall, appropriate dietary lysine levels (2.44%) could improve the growth performance, reduce the whole-body lipid, promote glycolysis and lipolysis.
Facilitative glucose transporter 4 (GLUT4) plays a central role in mediating insulin function to ... more Facilitative glucose transporter 4 (GLUT4) plays a central role in mediating insulin function to increase glucose uptake in glucose metabolism homeostasis. In this study, the function and localization of GLUT4 in blunt snout bream (Megalobrama amblycephala) were first investigated, and then, the response measured as carbohydrate level, was analyzed. The results showed that the cDNA sequence of GLUT4 in blunt snout bream (MaGLUT4, GenBank accession no: MT447093) was 2868 bp in length, and the corresponding mRNA contained a 5-UTR region of 513 bp and a 3-UTR region of 837 bp. MaGLUT4 had an open reading frame of 1518 bp and was encoded by 505 amino acids. Its theoretical isoelectric point and molecular weight was 6.41 and 55.47 kDa, respectively. A comparison of these characteristics with BLASTP results from the NCBI database showed that MaGLUT4 had the highest homology with Cypriniformes fish, with MaGLUT4 and GLUT4 of other Cypriniformes clustered in the phylogenetic tree with other GLUT1-4 amino acid sequences. Compared with the results from the homo_sapiens and mus_musculus data sets, some mutations were observed in the GLUT4 amino acid sequence of these aquatic animals, including an FQQI mutation to FQQL, LL mutation to MM, and TELEY mutation to TELDY. MaGLUT4 was constitutively expressed in the muscle, intestine, and liver, with the highest mRNA level observed in muscle. Furthermore, the predicted tertiary structure and results of immunohistochemical staining showed that MaGLUT4 was a transmembrane protein primarily located in the plasma membrane, where it accounts for 60.9% of the total expressed, according to an analysis of subcellular localization. Blood glucose level peaked within 1 h, and the insulin level peaked at 6 h, while the mRNA and protein levels of GLUT4 showed an upward trend with an increase in feeding time and decreased sharply after 12 h. These results confirmed that MaGLUT4 was mainly distributed in muscles and crosses the cell membrane. The changes in the insulin,
Fish is an extremely perishable food product which requires proper handling soon after harvest. T... more Fish is an extremely perishable food product which requires proper handling soon after harvest. The present study was aimed at assessing post-harvest fish losses and preservation practices in Siavonga district, Southern Zambia. Structured and semi-structured questionnaires were used to collect data on post-harvest fish losses and preservation practices from aquaculture producers, artisanal, and commercial fishers. All the fishers who landed on the lakeshore were interviewed, while aquaculture producers were randomly selected based on the information provided by the local department of fisheries. The results of the study revealed that all the fishers experienced post-harvest fish losses at varying degrees with those losing up to 10% of the total catch being in the majority. In contrast, aquaculture producers did not report any post-harvest fish losses. Most aquaculture producers commonly used chilling as preservation practice contrary to artisanal and commercial fishers who commonly ...
Abstract Cage aquaculture is among the recent innovations that have attracted great attention in ... more Abstract Cage aquaculture is among the recent innovations that have attracted great attention in fish production in most African countries. In Zambia, cage aquaculture has recorded significant growth to even emerge as the largest contributor to the total national aquaculture production annually. Our study was aimed at assessing cage aquaculture production in Siavonga district of Zambia. We targeted the aquaculture and feed manufacturing companies, their production, challenges, and opportunities. This study revealed that there were five main aquaculture production companies with fish cages ranging from 96 m3 to 135,534 m3 in size. Oreochromis niloticus was found to be the only cultured species. Lack of quality fish seed and feed were the major challenges faced by the aquaculture production companies in Siavonga district. The study further revealed that there were two major aquafeed manufacturing companies within the district with a production capacity ranging from 50 tons to 200 tons per day. Lack of readily available raw material for feed making was the major challenge facing the aquafeed manufacturing companies. There are huge potentials for cage aquaculture in Siavonga district, which can significantly contribute to the nation's aquaculture production. These include the availability of large fish feed manufacturing companies and huge water resources.
Extension programs in rural communities play a critical role in linking farmers and other actors ... more Extension programs in rural communities play a critical role in linking farmers and other actors in rural developmental agenda. The relevance of these programs in agriculture is largely dependent on their ability to meet farmers' needs since they are the stakeholders at the grassroots. This paper aimed to review studies on enhancing the role of rural agricultural extension programs in poverty alleviation. Various approaches and tools used in rural extension program delivery have been discussed, and ways in which their contribution to poverty alleviation can be enhanced have been highlighted. Extension programs have undergone many changes throughout the years in response to farmers' changing needs as well as the market they operate in. Therefore, there is no "one-size-fits-all" approach recommended for effective service delivery and outcome due to different farmer needs that are affected by their geographical location, social and economic structures. We conclude that rural extension programs can provide a sustainable solution to Sahya Maulu ABOUT THE AUTHORS Sahya Maulu is a board chairperson at Centre for Innovative Approach Zambia (CIAZ). His research focuses on agriculture, fisheries, aquaculture, rural development, and climate Change. Oliver Jolezya Hasimuna is an Aquaculture Research Officer at the Zambian Department of Fisheries. His research interest includes Aquatic Ecology, fish anesthetics, fish nutrition, fish breeding and genetics, aquatic animal diseases, and fisheries management Bornwell Mutale is a master's degree student at Ocean University of China. His research interests include agriculture and fisheries economics, rural development through agriculture, and environmental economics. Joseph Mphande is a Fisheries Officer at the Zambian Department of Fisheries. His research interests are in fisheries management, Morphometrics and meristic, Fish diseases, genetics, Climate change, microplastics and their impacts on aquatic biota Enock Siankwilimba is a co-founder and agricultural diversification manager at Musika Zambia. His research focuses on agricultural market systems development, livestock and crop business models, climate change, value chain development and rural development.
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