Carbohydrate and lipid digestibility of animal and vegetal ingredients and diets for the pre-adult redclaw crayfish, Cherax quadricarinatus (von Martens)

Abstract

In vivo carbohydrate and lipid digestibility of four animal [sardine meals 67% and 58% crude protein (CP), squid meal and red crab meal] and three vegetal (soy paste, textured wheat and sorghum meal) ingredients and diets were evaluated in experimental diets for pre‐adult redclaw crayfish, Cherax quadricarinatus. A reference and seven experimental diets were formulated, including 14.5% of each ingredient in the reference diet. A single factor, completely randomized experimental design with five replicates per treatment was done. Experimental organisms were pre‐adult redclaw of 10±0.8 g. The best carbohydrate digestibilities were recorded for some vegetal ingredients such as sorghum and textured wheat (93.6% and 83.9%) and the corresponding diets (90.9% and 90.8%). For animal ingredients, carbohydrate digestibilities were very poor (from 12.3% to 41.1%), and the inclusion of these ingredients diminished the digestibility of the corresponding experimental diets as compared with the reference diet (86.3–89.2% vs. 89.9%). The highest lipid digestibility corresponded to red crab meal (97.5%). Textured wheat and soy paste meal also had excellent lipid digestibility (96.4% and 95.1%). The same tendency was found for the corresponding diets. The lowest percentages were obtained with 58% crude protein sardine meal (32.9%) and its diet (86.2%).