Nguyen Thi Ngoc Anh

Seaweed, Enteromorpha intestinalis, as a Diet for Nile Tilapia Oreochromis niloticus Fry

A 42-d feeding trial was carried out to assess the potential use of the seaweed Enteromorpha intestinalis (“gutweed”) as a food source for monosex Nile tilapia (Oreochromis niloticus) fry and to determine a maximum threshold fishmeal substitution rate. Six fish diets randomly assigned to tilapia juvenile and in triplicate were compared: replacing 0%, 10%, 20%, 30%, 40%, and 50% of fishmeal protein with a gutweed protein blend. Highest growth and cost reduction in tilapia fry production was observed in fish fed a 20% replacement diet.

Formulated Feeds Containing Fresh or Dried Artemia as Food Supplement for Larval Rearing of Black Tiger Shrimp, Penaeus monodon

Supplementation of microalgae and Artemia nauplii with practical formulated feeds containing fresh or dried Artemia biomass for larval rearing of black tiger shrimp, Penaeus monodon, was assessed. Five feeding treatments were carried out in a recirculating seawater system with fifteen 30-L fiberglass tanks. Shrimp nauplii were stocked at a density of 150 L−1 for 23 days. In the control treatment, live feed was supplemented with commercial formulated feed (Inve Aquaculture NV, Belgium). In two other treatments, live feed was supplemented with a pelleted feed based on either fresh or dried Artemia. In the remaining two treatments live feed was supplemented with a combination of 50% commercial feed and 50% fresh or dried Artemia feeds. Overall, performance of PL in the combination treatments (commercial feed and Artemia diets) were equal to or better than those fed commercial feed alone as seen by the better growth rate and higher resistance to formalin stress. The results indicate that feed containing fresh or dried Artemia biomass can partially supplement live feeds for larval rearing of P. monodon.

Yield and Economic Efficiency of Green Water in Combination with Supplemental Feeds for Artemia Production in Vietnamese Salt Ponds

We evaluated the combined effects of different green water sources and feed supplements on Artemia biomass production and economic efficiency. A two-factor experiment was set up with two green water types produced from the ratios of nitrogen and phosphorus (N:P = 5 and N:P = 10) in combination with two types of supplemental feed (rice bran or pig manure). After 12 weeks of culture, total Artemia biomass yield with the N:P = 5 treatment (2.29 ton ha−1 crop−1) was 14% higher than that with the N:P = 10 treatment (1.97 ton ha−1 crop−1), although this difference was not significant (P > 0.05). There was no significant interaction between green water and supplemental feeding treatments for the final yield of Artemia biomass. Comparative cost-benefit analysis showed that the treatment of N:P = 5 combined with pig manure attained a significantly higher net profit and cost/benefit ratio than the other treatments.