Biosecurity maintenance and health management of shrimp in a hatchery system consistent with organic aquaculture requirements

Khor, Laura Li Imm (2008) Biosecurity maintenance and health management of shrimp in a hatchery system consistent with organic aquaculture requirements. Masters thesis, University Malaysia Sabah.

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Abstract

Shrimp are susceptible to bacterial infection due to their weak innate immunity which lacks secondary immune protection. Hence, this study seeks to examine alternative methods of protecting shrimp stocks from infection, while conforming to organic aquaculture and biosecurity standards. Measures were taken to enhance the stamina and immunity of tiger shrimp using bioencapsulated chitin and chitosan, commercial feed supplements, immunostimulants, artificial substrate (Aquamats®) and Azadirachta excelsa seed extract. All shrimp were evaluated in terms of mean weight gain, feed conversion ratio (FCR), specific growth rate (SGR), survival during the culture period and after exposure to stress or bacterial infection. In general, chitosan-fed shrimp had lower weight gain, whereas chitin produced higher biomass and lower FCR for dietary bloodworm treatment. Organic manganese and Shrimp Pak imparted significantly higher survival in challenged shrimp, while Bio-Mos, Shrimp Pak and NuPro improved weight gain and lowered FCR. There was overall higher survival in Booster D (Bacillinum) and seed extract-treated shrimp after bacterial challenge. The Aquamats® treatment significantly lowered ammonia content and FCR, while improving the shrimp's resilience to stress. Addition of A. excelsa seed product to seawater significantly inhibited the growth of Vibrio harvey,. Although Vibrio hatveyi was highly susceptible to oxytetracycline, the antibiotic was less effective in curbing bacterial growth in seawater. Singularly, the benefit derived from these applications may be marginal. However, the integration of these five components can be used as an all-round biosecurity measure to boost shrimp resistance to infection and combat bacterial pathogens.

Item Type:Thesis (Masters)
Uncontrolled Keywords:shrimp, biosecurity, organic aquaculture, weight gain, feed conversion ratio (FCR), culture period
Subjects:Q Science > QL Zoology
Divisions:SCHOOL > Borneo Marine Research Institute
ID Code:8965
Deposited By:IR Admin
Deposited On:08 May 2014 15:51
Last Modified:08 May 2014 15:51

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