Food Utilization in the Common Carp Cyprinus carpio in Relation to Formulated Feeds

Abstract

A 30-day feed trial was conducted to examine the effects of two groups of formu­lated pelleted feeds (beef waste + rice bran + groundnut oil cake; fish waste + soybean seeds + Spirogyra maxima) on the growth and body composition of the common carp Cyprinus carpio. Fish fed on beef-based feeds showed a slight increase in the rates of feeding, absorption and metabolism. The highest feeding rate of 1,460 J-g-Lday1 and the highest conversion rate of 182 J·g-1·day1 were noticed in C. carpio fed on these feeds. The absorption efficiency was higher in fish-based feeds (77-89%) than in beef-­based feeds (65-72%), but the food conversion efficiency showed the reverse trend. Increase in protein content of the diets produced elevated values in the rates and efficiencies of food conversion in all eight experimental feeds. A positive linear relation­ship was obtained between energy density of the diets and food conversion efficiency. The highest food conversion ratio of 1. 7 was noticed in C. carpio fed on 2:1 :1 mixtures by dry weight of the above ingredients in both groups.