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Email the author (Login required) Protein requirement for juveniles of Leiarius marmoratus (Siluriformes: Pimelodidae), with two dietary energy levels
Submited: 2025-10-21 22:06:32 | Published: 2026-04-30 21:53:18
DOI: https://doi.org/10.3856/vol54-issue2-fulltext-3556
Abstract
The yaque catfish, Leiarius marmoratus, is a native South American fish with characteristics that make it a promising species for aquaculture; however, its nutritional requirements at any developmental stage remain unknown. To determine the protein requirement for juveniles of L. marmoratus and evaluate the protein-sparing effect by increasing dietary energy, a feeding experiment was conducted with five levels of crude protein in the diet (22, 28, 34, 40, and 47%) and two energy levels (3,400 and 3,750 kcal metabolizable energy kg-1 diet). A total of 450 yaque fingerlings weighing 0.80 ± 0.1 g were used, randomly distributed in 30 tanks (15 fish tank-1), fed to apparent satiation twice daily for 60 days. Zootechnical performance parameters were determined: weight gain (WG), feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), condition factor (K), and survival (S). Final weight, WG, K, and PER were influenced by protein level (P < 0.05), but not by energy level. Significance was detected in the protein-energy dietary interaction. Feed intake, FCR, and SGR were not significantly affected by energy level (P > 0.05) but were affected by protein level (P < 0.05). The protein-sparing effect was evident when the energy level increased from 3,400 to 3,750 kcal kg-1. The protein requirement for juvenile yaque, determined by a second-order polynomial regression model, is between 38.1 and 42.0% crude protein, depending on the energy level present in the diet.
