Evaluating the Effect of Heteronitrogenous and Heterolipidic Diets (Commercial Feeds) on Growth Parameters of Rainbow Trout (Oncorhynchus mykiss) Fingerlings in Meghalaya

Abstract

Rainbow trout is a popular candidate species in aquaculture due to its rapid growth rate, excellent feed conversion capacity and high market value. The success of Rainbow trout farming relies heavily on maintaining optimal water quality parameters, which include water flow, temperature, dissolved oxygen, pH, ammonia and nitrate levels. This study investigated the growth performance of Rainbow trout (Oncorhynchus mykiss) fingerlings in the hilly region of Meghalaya, focusing on the impact of heteronitrogenous and heterolipidic formulated diets. The experiment was conducted between September 2024 and January 2025, under specific water conditions, including temperature, pH, dissolved oxygen, total alkalinity, hardness, ammonia, carbon dioxide and water flow. In this study, there was one control and three treatments with 3 replications. The growth parameters, such as growth rate, specific growth rate, weight gain, percentage weight gain and survival rate were monitored during the studies. One-way ANOVA was followed by Tukey HSD’s multiple range test to determine differences between treatment means. All the statistical analysis was performed using SPSS (Version 25.0). The weight gain, percent weight gain and SGR value were found significantly highest in control (1.71 ± 0.03 % day-1) with the lowest FCR of 0.96 ± 0.04. High FER was recorded in control (1.042 ± 0.05) and PER (2.315 ± 0.09) fed with 45% CP. The outcomes of this study offer critical insights into the effectiveness of commercial feed types for aquaculture in Meghalaya, emphasizing the need for customized feeding strategies to enhance Rainbow trout growth in cold-water ecosystems. The work emphasizes the relevance of species-specific diet formulation that considers nutritional requirements and points out that commercially obtainable feeds may prove effective as long as their protein and lipid contents were attuned to physiological and metabolic demand. Future studies must investigate the long-term effects of the diets on body constitution, digestive enzyme profiles, economic acceptability, and compatibility for incorporation of local feed components to make the operation less dependent on external commercial feeds and more sustainable at the local level.