Nucleic Acid Content Changes of a Tropical Freshwater Fish Labeo rohita Fed Gelatinized and Nongelatinized Starch Diet

Abstract

A 60‐d feeding trial was conducted to study the effect of dietary gelatinized (G) and nongelatinized (NG) starch on deposition of nucleic acid in liver and muscle of Labeo rohita juveniles. Two hundred and thirty‐four juveniles (av. wt. 2.53 ± 0.04 g) were randomly distributed into six triplicate experimental groups. Six semipurified diets containing graded levels of (0, 20, 40, 60, 80, 100) NG and G corn starch, were prepared accordingly: T1 (100% NG, 0% G); T2 (80% NG, 20% G); T3 (60% NG, 40% G); T4 (40% NG, 60% G); T5 (20% NG, 80% G); and T6 (0% NG, 100% G). After a feeding period of 60 d, DNA content in muscle and liver decreased linearly with increasing level of G starch in the diet, whereas protein/DNA in muscle increased linearly with increasing levels of G starch in the diet. No significant effect of G starch on RNA deposition in liver and muscle was found. RNA/DNA ratio increased linearly with increasing level of gelatinized starch in the diet. Results from this study indicate that protein/DNA and RNA/DNA ratio in muscle increase with increasing levels of G starch in the diet, which also reflects in terms of growth performance.