Effect of Gelatinized Corn Meal as a Carbohydrate Source on Growth Performance, Intestinal Evacuation, and Starch Digestion in Common Carp

Abstract

This study investigated the nutritive value of gelatinized corn meal to common carp, including the effect of gelatinization on intestinal evacuation and starch digestion. Fish were fed diets containing raw and extruded corn meal in three proportions at a 40% dietary level, with dietary gelatinized ratios (GR) of 28, 72, and 100%,. In the first experiment (growth trial) with fingerlings, the percent gain was similar in all groups, but feed efficiency and protein efficiency ratio improved with increasing level of GR. The daily feed consumption decreased with increase of GR. The starch apparent digestibility improved by increasing the GR level. The energy digestibility also slightly improved with increase of GR. In the second experiment (evacuation trial) with juveniles, the food evacuation time from the anterior section of the intestine was very similar in all diets, suggesting no difference in food passage time in the digestive tract. The apparent starch digestibility in the different sections of the intestine increased gradually with time after feeding in all diets. However, starch digestion was much faster for the diets with higher GR. It can be concluded that an increase of gelatinization ratio improves the nutritive value of corn meal for common carp and this might be due to the acceleration of starch digestion in the intestine. © 1994, The Japanese Society of Fisheries Science. All rights reserved.