Insight into genetic potential for growth and survival of the Pacific white shrimp (Litopenaeus vannamei) in the context of low-protein and low-fishmeal diet use

This study assessed genetic parameters including genotype by diet interactions in growth and survival of Pacific white shrimp (Litopenaeus vannamei) fed with a low-protein and low-fishmeal diet (protein: 35%, fishmeal: 9%) and a general commercial diet (protein: 42%, fishmeal: 25%). A total of 2774 shrimp from 38 families were divided into two groups for a feeding trial, an experimental group fed with the low-protein and low-fishmeal diet and a control one fed with the commercial diet. A 7.06% increase in BW of shrimp fed the control diet over the experimental diet, and no significant difference in survival rate between the diets was observed after 75 days of trial. There was no significant difference between heritability estimate of BW on the experimental diet (0.671 +/- 0.119) and that on the control diet (0.585 +/- 0.108; p > 0.05), and heritability estimate of survival on the experimental diet (0.199 +/- 0.047) was significantly higher than that on the control diet (0.050 +/- 0.019; p < 0.01). Genetic correlation between BW recorded on the two diets was very high (0.928 +/- 0.042), indicating an insignificant genotype by diet interaction effect for this trait. Relatively, genetic correlation for survival was low (0.251 +/- 0.160), indicative of genotype by diet interaction effect. Our results indicate that 35% protein and 9% fishmeal in diets with high level of plant-based protein are feasible in inducing acceptable growth and survival of L. vannamei. This study confirms that the current low-protein and low-fishmeal diet is an appropriate environment for evaluating and selecting genotypes for improved growth of L. vannamei.