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罗省延洲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。目前的水产养殖系统，即大型草食性草鱼与3-5种其他（非草食性）鱼类混养，以及使用绿叶、粪便和作物残留物作为鱼类饲料，其生产力主要受到两个因素的限制：草鱼的一种迄今未知的疾病，以及缺乏适合其他物种的饲料基础。该项目的目标是为非草食性鱼类的适应性饲料发展科学基础，以及草鱼病的诊断和可能的预防或治疗。目前，大多数池塘采用流水系统，这有利于草鱼的养殖，但由于营养物质的持续损失和高浊度，限制了其他物种天然食物的开发，从而限制了它们的生产。减少流量以提高初级生产的改良用水制度和使用适合补充饲料的改良饲养制度相结合，预计将大大改善鲤鱼、罗非鱼和其他鱼种的生长和产量，并增加农民的水产养殖收入和收入以及家庭鱼类消费。目前可获得的关于草鱼病的信息与该物种的任何已知病毒、细菌或寄生虫病都不相符。因此，预防或治疗这种疾病的任何战略只能在可靠诊断的基础上制定。

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.