Apparent digestibility of dry matter, protein, and essential amino acid in marine feedstuffs for juvenile whiteleg shrimp Litopenaeus vannamei

Apparent protein and amino acid digestibility coefficients of feedstuffs are needed for more accurate, environmentally friendly, and economical feed formulations for shrimp. Coefficients of digestibility of nine feedstuffs of marine origin were measured, in terms of apparent dry matter, protein, and essential amino acid, for juvenile whiteleg shrimp, Litopenaeus vannamei, using 1% chromic oxide as the inert marker. The tested ingredients included four commercial fish meals (FMs) from different sources, batches, or species designated as A, B, C and D, fish soluble protein concentrate (FSPC), squid (Loligo gahi) meal (SM), shrimp (Litopenaeus vannamei) head meal (SHM), red crab (Pleuroncodes planipes) meal (RCM), and Catarina scallop (Argopecten ventricosus) by-product meal (CSBM). A reference diet was formulated and produced along with the experimental diets which included 30% of each ingredient and 70% of the reference diet. Apparent dry matter and protein (APD) digestibility coefficients varied very much among feedstuffs, from 46% to 102% and from 64% to 99%, respectively. APD for the fish soluble protein concentrate, squid and shrimp head meals were excellent (over 90%), Catarina scallop meal and FMA (sardine 66% CP) showed high protein digestibility (over 84%), while red crab meal (77%), FMB (sardine 70% CP; APD 71%) and FMD (tuna 60% CP; APD 70%) had low digestibility. The lowest dry matter (46%) and protein (63%) digestibilities were recorded for FMC (sardine 70% CP). Apparent amino acid digestibility (AAAD) coefficients were also variable among feedstuffs, and there was a reasonable, but not total, correspondence to protein digestibility. The most digestible feed ingredients for whiteleg shrimp were: fish soluble protein concentrate, squid meal, shrimp head meal, Catarina scallop by-product meal, and fish meal A (sardine 66% CP) showing that these ingredients are good sources of available protein and amino acids for juvenile whiteleg shrimp.