Evaluation of dietary supplementation of aqueous extract of brown algae Sargassum cristaefolium on growth performance and feed utilization of juvenile white shrimp Litopenaeus vannamei

Abstract

A 42-day indoor feeding trial was conducted to evaluate the growth performance and feed utilization of juvenile white shrimp Litopenaeus vannamei fed with diets containing different supplement levels of hot-water extract of brown tropical macro algae Sargassum cristaefolium extract. The commercial white shrimp feeds containing 36% crude protein were incorporated with graded levels of brown algae S. cristaefolium extract (0, 200, 600, 1000 and 1400 mg kg-1) and used in the feeding trial. Shrimp (mean initial weight, 2.65±0.11 g) were fed three times daily ad libitum at an initial feeding allowance of 8% total body weight day-1. A completely randomized design was used in the study and shrimp were stocked at a density of 10 animals 30 L-1 black round plastic tank in triplicates. Results showed that the different levels of dietary brown algae extract supplement did not significatly affect (p > 0.05) on final body weight (10.6-11.3 g shrimp-1), survival (80-96.7%), and total moulting shrimp (36- 48 times). In terms of weight gain and average daily growth (ADG), the diets with no algae extract supplement and the highest extract inclusion level of 1400 mg kg-1 diet seemed to have better performance (p < 0.05) than other diets. However, the shrimp fed diets containing S. cristaefolium extract at 200, 600 and 1000 mg kg-1 diet showed a better feed utilization (Feed Conversion Ratio (FCR) 1.8-2.0; Protein Efficiency Ratio (PER) 1.40-1.56) than those of shrimp fed the algae extract at levels of 0 mg and 1400 mg kg-1 diet (FCR 2.38-2.47; PER 1.13-1.17). The results indicated that dietary S. cristaefolium extract supplementation had a significant influence (p < 0.05) on feed utilization. Shrimp fed the 200-1000 mg algae extract kg-1 diet had a significantly better FCR and PER (p < 0.05) than the shrimp fed the 0 mg and 1400 mg algae extract. These results suggest that supplementation of S. cristaefolium extract at a dose of 200-1000 mg kg-1 can be used to get a better feed utilization performance (reduce 22% FCR and enhance 27.8% PER) of juvenile white shrimp L. vannamei. However, a dose of 600 mg S. cristaefolium extract kg-1 diet is recommeded to add in diet to get a better FCR and PER performance of juvenile L. vannamei