Use of supplemental amino acids on the success of reducing dietary protein levels for Jian carp ( Cyprinus carpio var. Jian)

Abstract

A feeding trial was conducted to investigate the effects of essential amino acids (EAA) supplementation on the success of dietary protein reduction for Jian carp (Cyprinus carpio var. Jian). Five diets were formulated including a positive control (Diet 1, 378.4 g/kg protein), a negative control (Diet 5, 289.8 g/kg protein) and three test diets (Diet 2‐Diet 4, 340.4–299.0 g/kg protein supplemented with EAA). No significant decline of growth performance in fish fed decreased dietary protein with EAA supplementation, which were significantly higher than the negative control. The apparent digestibility coefficients (ADC) of protein and most EAAs were not significantly affected by the dietary treatments. Dietary treatments did not affect whole‐body composition, but influenced protein and EAAs retentions. Total ammonia nitrogen (TAN) excretion decreased with the decreasing dietary protein, and the highest plasma ammonia content was observed in fish fed Diet 5. Plasma glucose concentration increased with the decreasing dietary protein reduction, while other plasma parameters were not affected by dietary treatments. These results indicated that low‐protein diets (299.0 g/kg) supplemented with EAA can maintain protein, EAA digestibility and retention in Jian carp, and also has benefit in the reduction of TAN excretion.

Atividade das enzimas digestivas frente a restrição alimentar de peixes ornamentais

“…Após a ingestão, o alimento sofrerá alterações físico-químicas ao longo do trato intestinal, para então ser absorvido e metabolizado de acordo com as exigências do animal (Ren et al, 2019). A distribuição das enzimas no intestino dos peixes varia com o hábito alimentar e a morfologia tecidual (Tengjaroenkul et al, 2000).…”

Effects of reduced protein level and dietary amino acid supplementation on growth, body composition and intestinal morphometry of silver catfish ( Rhamdia quelen )

“…Ren et al. (2019) had a similar result and was attributed to the rapid release of ammonia from the plasma by the gills.…”

“…Some studies have shown that reduced level of CP and supplementation with AA bring satisfactory results for the growth of various species of fish (Gan et al., 2012; Jiang et al., 2018; Michelato et al., 2016; Ren et al., 2019). The availability of AA in free form results in greater absorption compared to AA bound to proteins (Nguyen & Davis, 2016; Zhou et al., 2007).…”

“…Ren et al. (2019) observed that feed intake was no different between diets supplemented with Lys and Met, suggesting that the Jian carp ( C. carpio Var. Jian) was well adapted to different levels of CP and fish meal in the diets.…”

“…Soybean meal has a low palatability and concentration of lysine (Lys) and methionine (Met), which can limit the use and growth of animals (National Research Council—NRC, 2011). However, the reduction of crude protein (CP) levels in the diet has been investigated, adding essential AA, especially Lys and Met, to meet the nutritional needs of fish in order to avoid adverse effects on growth (Abimorad, Favero, Castellani, Garcia, & Carneiro, 2009; Ren et al., 2019). By increasing the level of Lys and Met, the supplemented diet can improve the use of other excess AA, optimize anabolism and maximize the use of proteins in the diet (Jiang et al., 2018).…”