Effects of dietary energy and protein on productive performance of Oreochromis niloticus fry (chitralada strain)

Abstract

The purpose of this experiment was to evaluate the productive performance of Oreochromis niloticus fry chitralada strain, feed with different energy and protein levels. Six diets with two energy levels (3300 and 3600 kcal/kg.) and three protein levels (35, 40 and 45%) were implemented, generating six different energy / protein levels (10.28, 9.42, 9.0 8.25, 8.00 and 7.33 kcal ED/g PC). A batch of 192 fries which came from a commercial farm was distributed randomly in four treatment aquariums with a density of 8 individuals per aquarium. Food was provided at will twice a day (8:00 and 15:00 hours). The starting weight of the fry was registered, and later every 15 days, until day 45, in which the essay finished. Weight gain (GP), specific growth rate (TCE), alimentary conversion factor (FCA), the efficiency in energy and protein use (EUE and EUP), energy and protein retention rates (TRE and TRP) and survival were evaluated. It was concluded that for the (GP), 8.25 and 9.42 energy / protein relations were the best results (p<0.05). As per TCE, FCA, EUE y EUP there were not significant differences among the treatments used (p>0.05); a similar behavior was observed in TRP, but TRE was significantly superior (p<0.05) with an energy / protein relation of 7.33, and in general it was better in the treatments with 3300 kcal/kg with respect to 3600 kcal/kg. Survival was not affected by the treatments (p>0.05).