Dietary β-Glucan and Nucleotide Effects on Growth, Survival and Immune Responses of Pacific White Shrimp, Litopenaeus vannamei

Abstract

Effects of dietary supplementation of β-glucans and nucleotides on growth, survival and immune responses of the Pacific white shrimp (Litopenaeus vannamei) at a low salinity (5 ppt) were evaluated during a 30 d feeding trial. Final mean weight of shrimp fed nucleotides at 0.5% was highest and significantly different from those fed the basal diet or diets supplemented with β-glucans. Survival was significantly higher for shrimp fed the diet with 0.2% β-glucans compared to all other diets and was lowest for shrimp fed the basal diet. Shrimp fed diets containing β-glucans and nucleotides had generally better immune responses than shrimp fed the basal diet with higher total hemocyte count (THC) recorded for shrimp fed 0.2% β-glucans followed by those fed 0.2% nucleotides. Shrimp fed diets with 0.2% and 0.5% nucleotides and 0.2% β-glucans had significantly higher respiratory burst values than shrimp fed the basal diet. These results indicated that dietary supplementation of either nucleotides or β-glucans has beneficial effects in improving shrimp performance when cultured at low salinity.

KEYWORDS:

• dietary β-glucan
• nucleotide
• immune response
• growth
• pacific white shrimp

The first author is thankful to the Department of Biotechnology, Government of India, for sanctioning an overseas fellowship to conduct research at Texas A&M University. He is also thankful to Dr. Delbert Gatlin of Texas A&M University, College Station, Texas, USA, for providing the research facility.