Effects of feeding Atlantic salmon (Salmo salar L.) imbalanced levels of lysine and arginine

Abstract

Two experiments were performed to study the effects of imbalanced levels of arginine and lysine in diets of Atlantic salmon (Salmo salar L.) with Zein as the major dietary protein source. In the first experiment, the effects of high levels of lysine on marginal levels of arginine and high levels of arginine on marginal levels of lysine were compared in fish fed these amino acids at either marginal or high levels. Dietary contents of arginine/lysine were 30.0/29.4, 17.0/29.4, 30.0/14.4 and 17.2/14.5 g kg–1, respectively. In the second experiment, fish were fed increasing levels of lysine in a diet containing arginine at the requirement level. Dietary levels of arginine/lysine in the second experiment were 23.0/17.0, 23.0/34.3, and 23.0/46.4 g kg–1. Atlantic salmon fed marginal levels of lysine showed better growth and feed utilization when fed diets supplemented with high levels of arginine. Fish fed diets marginal in arginine exhibited increased growth and feed utilization when fed diets supplemented with high levels of dietary lysine. Increasing dietary lysine did not significantly affect growth in fish fed arginine at the requirement level. Increased growth in fish fed high dietary arginine levels might be explained by increased tissue concentrations of ornithine acting as a precursor for in situ synthesis of polyamines. A slight correlation between specific growth rate (SGR) and concentration of spermidine in muscle and between condition factor and concentration of total polyamines in muscle was seen. Abdominal injection of U‐C14 arginine may indicate lysine inhibition of arginine availability in muscle tissue.

Adição de lisina digestível em rações experimentais para juvenis de tilápia-do-nilo

“…No entanto, o uso dessas rações pode ser prejudicial para o crescimento dos peixes, pois reduz o consumo de ração em razão da reduzida palatabilidade apresentada (Berge et al, 2002), especialmente quando essas dietas são deficientes em aminoácidos essenciais, particularmente lisina (Dabrowski et al, 2007). No presente estudo, as tilápias foram alimentadas com dietas do tipo práticas e suplementadas com aminoácidos sintéticos, de forma a obterem os níveis nutricionais preconizados, não sendo observado efeito sobre o consumo de ração, independentemente do nível de lisina utilizado nas rações.…”

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“…The increased fish growth in this study was primarily due to improved feed utilization efficiency as significantly lower FCR and higher PER were obtained by increment of dietary isoleucine level. It has long been demonstrated that a balanced amino acids profile is required for effective utilization of dietary protein for tissue synthesis (D'Mello, 1994;Yamamoto et al, 2000;Berge et al, 2002;Green and Hardy, 2002;GoemezRequeni et al, 2003). In this study reduced growth was found in fish groups fed isoleucine deficient diets and those fed higher isoleucine levels than 1.43% probably indicating imbalances in dietary amino acids profile.…”

Dietary amino acid l-tryptophan requirement of fingerling Indian catfish, Heteropneustes fossilis (Bloch), estimated by growth and haemato-biochemical parameters

“…Balanced dietary amino acid profile is required for optimal growth and feed conversion in fish, as imbalances in the dietary amino acid pattern not only lead to reduction in feed intake and protein utilization for growth (Wilson and Halver 1986;D'Mello 1994;Yamamoto et al 2000;Berge et al 2002;Green and Hardy 2002;GomezRequeni et al 2003), but also have effects on nitrogen loading in water (Small and Soares 1999). Generally, the ingredients used for formulation of artificial feeds are limiting in four major essential amino acids such as lysine, arginine, methionine and tryptophan.…”