Changes in shrimp feed quality and effects on growth and survival of Penaeus monodon juveniles

Abstract

Five practical shrimp diets were formulated to contain 1, 10, 20, 50, and 100 g tetraethoxypropane (TEP) kg⁻¹ diet. A diet with no added TEP served as the control. Diets were fed to Penaeus monodon (average weight 4.84 ± 0.11 g) juveniles to determine the level of fat oxidation tolerable to shrimp. Changes in shrimp feed quality were monitored by physical evaluation, thiobarbituric acid (TBA) values, fatty acid composition, and histological examination. Effects of feed quality on growth and survival of shrimp were evaluated. Results showed significant differences (<i>P</i> &lt; 0.05) in TBA values among treatments. Animals fed on diet 6, which contained 100 g TEP kg⁻¹ diet, showed signs of physical deterioration after 6–8 weeks. This diet had a significantly higher TBA value (1262 mg malonaldehyde kg⁻¹ fat) than the other treatments. The unsaturated fatty acid content of the diet decreased as its TEP content increased. Weight gains of shrimp fed diet 5 (50 g TEP kg⁻¹ diet) and diet 6 were significantly lower than those fed the other diets while survival was similar. Hepatopancreatic lesions were not evident in all samples. Fat oxidation levels expressed in terms of TBA values of up to 828 mg mal kg⁻¹ fat can be tolerated by Penaeus monodon juveniles in terms of growth response.