Comparison of different types and levels of commercial soybean lecithin supplemented in semipurified diets for juvenile Litopenaeus vannamei Boone

Two 6-week growth trials were conducted to determine the dietary phospholip ids (PL) requirement of Litopenaeus vannamei juveniles and to compare the e ffect of different types of soybean lecithin on shrimp growth and survival. In the first trial, a basal diet and diets containing 1.5, 3 or 5% (dry-we ight basis) of Type I lecithin (97.6% PL) and 1.5 or 3% of Type II lecithin (71.4% FL) were evaluated. In the second trial, the basal diet and diets c ontaining 1, 2 or 4% of either Type I or Type II lecithin and 1 or 2% of Ty pe III lecithin (48.4% PL) were evaluated. Results showed that there was no interaction between lecithin type and PL level on shrimp growth or surviva l. Shrimp growth increased with PL levels up to 3-5% of diet. No significan t differences were observed for instantaneous growth rate (IGR) of shrimp f ed the different types of lecithin at the same inclusion level, and no effe ct of PL level and lecithin type on shrimp survival was found. Thus, the re commended level of PL supplementation in diets for L. vannamei juveniles ra nges from 3 to 5% of diet.