Apparent digestibility of protein and essential aminoacids from commonly used feed ingredients in Brazil for juvenile shrimp Litopenaeus vannamei

Abstract

This study determined the apparent digestibility for crude protein (ACPD) and essential aminoacids (AEAAD) of ingredients for Litopenaeus vannamei fed diets containing soy protein concentrate (SPC), corn gluten meal (CGM), poultry byproduct meal (PBM), meat and bone meal (MBM), hydrolyzed feather meal (HFM), spray-dried blood meal (DBM), tilapia byproduct meal (TBM), Brazilian marine fish meal (BFM), salmon byproduct meal (SLM), and krill meal (KRM). Digestibility was estimated using chromic oxide as a marker in a reference (REF) mixture. Shrimp of 6-8 g body weight were reared over three separate experimental stages lasting 29-30 days each. Shrimp survival exceeded 96% and was unaffected by test ingredient. The ACPD ranged from 66.7% for a diet containing DBM to 84.2% for the REF diet. Higher ACPD were observed for aquatic compared with plant and terrestrial animal byproducts. Aside from SPC (79.3%), ACPD for CGM was low at 47.5%. Among terrestrial animal byproducts, ACPD was higher for MBM compared with PBM, DBM, and HFM (71.2, 62.8, 48.6, and 45.9%, respectively). With the exception of BFM (59.7%), ACPD for all other aquatic proteins was high (KRM, 84.3%; TBM, 83.3%; SLM, 78.9%). Aquatic proteins have higher crude protein (CP) and essential aminoacid (EAA) digestibility for shrimp. Ingredients SLM, SPC, TBM, and KRM are preferable in feeds for the whiteleg shrimp since they carry a high CP and EAA content (>600 g kg−1) combined with ADC near or in excess of 80%.