Corn distiller's dried grains with solubles: Apparent digestibility and digestive enzymes activities in European seabass (Dicentrarchus labrax) and meagre (Argyrosomus regius)

Abstract

Abstract Corn distillers dried grains with solubles (DDGS) is a co-product of corn ethanol production which biological value is dependent on technological processes and so may be highly variable among production plants. Therefore, two digestibility trials were conducted to evaluate the apparent digestibility coefficients (ADCs) of nutrients and energy of two commercial sources of DDGS and their effects on digestive enzyme activities in European seabass and meagre juveniles. DDGS digestibility was determined based on the substitution of 30% of a reference diet (45% CP; 16% CL) by each test DDGS. ADCs of protein (92–98%), most amino acids (75–99%) and lipids (82–89%) were high while that of energy (58–68%) was low, reflecting the high indigestible fiber content of DDGS. ADCs of nutrients and energy of DDGS were similar in both species, except for some amino acids (lysine, arginine, histidine, isoleucine, tyrosine and aspartic acid) which were higher for seabass than for meagre. Independent of fish species, ADCs of protein and energy were higher in DDGS1 than in DDGS2, whereas ADCs of lipids and most amino acid were not affected by DDGS source. Digestive enzymes activities were species specific: protease activity was higher in meagre while lipase and amylase activities were higher in seabass. For both species, all digestive enzymes activities were higher in mid intestine than in anterior or distal intestine. Overall, it is concluded that corn DDGS is well digested and seems to have high potential for inclusion in diets for seabass and meagre juveniles.