Onderwerp scriptie

Analysis of the main pathologies in the Vietnamese shrimp production systems and available solutions - Sjoerd Bakker

The Vietnamese shrimp industry is affected by several shrimp pathologies. Shrimp diseases are multifactorial issues for farmers. The purpose of the current study is to determine the disease favoring factors at farm level, assess all technical solutions that are offered to farmers and give a first insight on the way of thinking of the Vietnamese farmers about this issue.

Information originates from literature research, three marine hatcheries visits and six shrimp experts’ interviews.
Vietnamese shrimp production systems are divided in a hatchery and a grow-out phase. The three main shrimp diseases identified are the Acute Hepatopancreatic Necrosis disease, the infection by microsporidian Enterocytozoon hepatopenaei and White Spot Syndrome Virus. The main entrance pathways for pathogens into the farm are water borne routes, infected post-larvae and other live vectors. The multiplication of pathogens within the farm is favored by the water parameters. In most grow-out farms, it can be considered that the main pathogens are always present and the infection of a shrimp occurs when its immune system is weakened because of stress factors.
Solutions concern the whole production process, namely the external biosecurity, the facility preparation, water, feed and shrimp quality and the disinfection of shrimps. During the hatchery phase, total disinfection of the water can be carried out. In the grow-out units, it is neither possible nor desirable to eradicate all pathogens in a shrimp farm and solutions consist in managing the pathogen load in the water column. Water quality in grow-out units goes along with the pond bottom quality. Shrimp entering a farm should be unscathed and of high genetic quality. Live shrimp feed used during the hatchery phase has to originate from reliable sources and should be disinfected.
Despite having sufficient knowledge, Vietnamese farmers are not implementing solutions against the principal shrimp pathologies due to trust issues and financial constraints. It is recommended for the government to provide technical information and loans to farmers in order to push them to implement these crucial changes for the future of the Vietnamese shrimp industry. The Vietnamese government is also responsible for the supply of high quality broodstock and promoting research on shrimp diseases.

Student: SS Bakker

Supervisor: ing F Steenstra

30 Ects