Research of improved fish nutrition and fish health in upland aquaculture systems in Yen Chau, Son La Province, Vietnam

水产养殖对越南北部松拉省延州的泰国黑人农民的蛋白质供应和现金收入做出了重要贡献。目前水产养殖系统的生产力，即大型草食性草鱼与其他3-5种(非草食性)鱼种混养，以及使用绿叶、粪便和作物残渣作为鱼类饲料，主要受到两个因素的限制：一种迄今未知的草鱼疾病，以及缺乏适合其他物种的饲料基地。该项目的目标是开发非草食性鱼类适应饲料的科学基础，并诊断草鱼疾病和可能的预防或治疗。目前，大多数池塘采用流水式养殖，这有利于草鱼的养殖，但限制了其他鱼种天然饲料的开发，从而限制了其他鱼种营养物质的不断流失和高浊度的生产。为提高初级产量而减少流量的改良供水制度和使用适合补充的饲料的改良饲养制度相结合，预计将显著改善鲤鱼、罗非鱼和其他物种的生长和产量，增加农民的收入和水产养殖收入以及家庭鱼类消费。目前关于草鱼疾病的信息与该物种的任何已知病毒、细菌或寄生虫病都不匹配。因此，任何预防或治疗这种疾病的策略都只能在确凿的诊断基础上制定。

Aquaculture importantly contributes to protein supply and cash income of Black Thai farmers in Yen Chau, Son La province, Northern Vietnam. The productivity of the current aquaculture system, the polyculture of the macroherbivorous grass carp together with 3-5 other (nonherbivorous) fish species and the use of green leaves, manure and crop residues as fish feeds, is limited mainly by two factors: A so far unknown disease of grass carp and the lack of a suitable feed base for the other species. The goals of this project are the development of the scientific base for adapted feeds for the non-herbivorous fish species and the diagnosis of the grass carp disease and possible prevention or cure. Currently, most ponds are operated as flow-through-systems, which is advantageous for the culture of grass carp, but limits the development of natural food for the other species and thereby also their production by continuous loss of nutrients and high turbidity. The combination of a modified water regime reducing flows in order to enhance primary production and a modified feeding regime using diets suitable for supplementation is expected to significantly improve the growth and production of common carp, tilapia and other species and increase the farmers’ income and revenue from aquaculture as well as home consumption of fish. The information currently available on grass carp disease does not match with any known viral, bacterial or parasitic disease of this species. Therefore, any strategies for prevention or treatment of this disease can only be developed on the basis of a solid diagnosis.