[Objective] The aim was to discuss the effects of probiotics on the growth of Cyprinus carpiod and water quality. [Method] Taking C. carpiod as the research object, probiotics were supplemented in the fodder and water...[Objective] The aim was to discuss the effects of probiotics on the growth of Cyprinus carpiod and water quality. [Method] Taking C. carpiod as the research object, probiotics were supplemented in the fodder and water to study their effects on the growth of C. carpiod and water quality. [Result] Probiotics had promoting effects on the growth of C. carpiod and its optimum dosage was 6%. pH, ammonia nitrogen content and nitrite content in water body in experimental groups were all lower than those in control group. [Conclusion] Compound probiotics had a broad application foreground in the aquatic breeding industry.展开更多
The economic viability and social value of traditional aquaculture in rural Sierra Leone were evaluated. The hypothesis tested was that traditional methods of farming fish in ponds were not economically viable, so far...The economic viability and social value of traditional aquaculture in rural Sierra Leone were evaluated. The hypothesis tested was that traditional methods of farming fish in ponds were not economically viable, so farmers were investing their time/labour in less risky and more profitable livelihoods activities. The assumption in this assessment was that fish farming is an economic activity, and that for farmers to adopt or choose it over other livelihoods, the benefit-cost ratio of fish farming must be higher than that of alternative livelihoods. The main objective of the study was to assess why local farmers failed to adopt modem market oriented aquaculture production systems introduced by the Ministry of Fisheries and Marine Resources in rural Sierra Leone. Two hundred farmers owning fishponds on family lands were interviewed using semi-structured questionnaires and farmers＇ responses were analyzed using statistical tools （SPSS 16.0）. The mean contributions of different livelihoods to total annual incomes of farmers and the social values they attached to these livelihoods were compared. Results of the study suggested that traditional fish fanning was economically viable across the range of pond sizes sampled; but the medium-sized ponds were more profitable than the smallest and largest ponds, and labour accounted for 70% of total annual production costs in the systems assessed. The average benefit-cost ratio of 2.3 for fish fanning was favorable compared with that of 0.83 for rice farming, which was ranked as most popular livelihood activity by farmers. The payback period for traditional aquaculture investments was less than five years using informal investment loans （without interest）, and was favorably compared with that for tree crops fanning, which was also popular among farmers. Additional benefits of fish fanning included social capital and maintenance of kinship relationships.展开更多
基金Supported by the Project of Quality Safety of Agricultural Products Loaned from World Bank of Jilin Province
文摘[Objective] The aim was to discuss the effects of probiotics on the growth of Cyprinus carpiod and water quality. [Method] Taking C. carpiod as the research object, probiotics were supplemented in the fodder and water to study their effects on the growth of C. carpiod and water quality. [Result] Probiotics had promoting effects on the growth of C. carpiod and its optimum dosage was 6%. pH, ammonia nitrogen content and nitrite content in water body in experimental groups were all lower than those in control group. [Conclusion] Compound probiotics had a broad application foreground in the aquatic breeding industry.
文摘The economic viability and social value of traditional aquaculture in rural Sierra Leone were evaluated. The hypothesis tested was that traditional methods of farming fish in ponds were not economically viable, so farmers were investing their time/labour in less risky and more profitable livelihoods activities. The assumption in this assessment was that fish farming is an economic activity, and that for farmers to adopt or choose it over other livelihoods, the benefit-cost ratio of fish farming must be higher than that of alternative livelihoods. The main objective of the study was to assess why local farmers failed to adopt modem market oriented aquaculture production systems introduced by the Ministry of Fisheries and Marine Resources in rural Sierra Leone. Two hundred farmers owning fishponds on family lands were interviewed using semi-structured questionnaires and farmers＇ responses were analyzed using statistical tools （SPSS 16.0）. The mean contributions of different livelihoods to total annual incomes of farmers and the social values they attached to these livelihoods were compared. Results of the study suggested that traditional fish fanning was economically viable across the range of pond sizes sampled; but the medium-sized ponds were more profitable than the smallest and largest ponds, and labour accounted for 70% of total annual production costs in the systems assessed. The average benefit-cost ratio of 2.3 for fish fanning was favorable compared with that of 0.83 for rice farming, which was ranked as most popular livelihood activity by farmers. The payback period for traditional aquaculture investments was less than five years using informal investment loans （without interest）, and was favorably compared with that for tree crops fanning, which was also popular among farmers. Additional benefits of fish fanning included social capital and maintenance of kinship relationships.
