Optimal dietary methionine requirement of juvenile Chinese sucker,Myxocyprinus asiaticus

Abstract

A total of 630 juvenile Chinese sucker, with an average initial weight of 1.72 AE 0.05 g, were fed seven diets for 56 days to study the effect of dietary methionine levels on growth, feed utilization, body composition and haematological parameters on juvenile Chinese sucker. Diet 1 using fish meal as the sole protein source and diets 2-7 using fish meal and fermented soybean meal as intact protein sources supplemented with crystalline amino acids contained six levels of L-methionine ranging from 6.4 to 18.9 g kg À1 of dry diet at a constant dietary cystine level of 3.7 g kg À1 .Each diet was randomly assigned to three aquaria. Results indicated that the highest weight gain, specific growth rate (SGR), feed efficiency ratio, protein efficiency ratio and protein productive value occurred at 13.9 g methionine kg À1 diet among the methionine supplemented dietary groups, beyond which they showed declining tendency. The whole body and muscle protein contents of juvenile Chinese sucker were positively correlated with dietary methionine level, while muscle lipid content was negatively correlated with it. The total essential amino acids content of muscle was increased significantly with increasing dietary methionine level from 6.4 to 13.9 g kg À1 (P < 0.05). Apparent digestibility coefficients of dietary protein were significantly affected by dietary treatments. Serum protein, cholesterol and triacylglycerol increased with increasing dietary methionine levels, but showed a relatively lower value for fish fed the 18.9 g methionine kg À1 diet. Quadratic regression analysis of SGR against dietary methionine level indicated that optimal dietary methionine requirement for juvenile Chinese sucker was 14.1 g kg À1 of the diet in the presence of 3.7 g kg À1 cystine (corresponding to 32.0 g kg À1 of dietary protein on a dry-weight basis).

The effect of dietary methionine on growth, antioxidant capacity, innate immune response and disease resistance of juvenile yellow catfish (Pelteobagrus fulvidraco)

“…; Chu et al . ). However, the TSAA requirement of the yellow catfish was higher than other fish species (Moon & Gatlin ; Kim et al .…”

“…; Ahmed ; Chu et al . ). In the present study, fish fed a diet containing lower dietary methionine had lower PWG, SGR, FE and PER than those fed diets that included higher dietary methionine levels.…”

Effect of dietaryl-methionine concentrations on growth performance, serum immune and antioxidative responses of juvenile Nile tilapia,Oreochromis niloticus

“…Methionine is an indispensable amino acid for tilapia (Jackson & Capper ; Santiago & Lovell ; Furuya, Pezzato, Pezzato, Barros & de Miranda ; Nguyen ; Nguyen & Davis ). Methionine deficiency results in bad growth and feed efficiency and even leads to the development of cataracts in fish (Keembiyehetty & Gatlin ; Ruchimat, Masumoto, Hosokawa & Shimeno ; Simmons, Moccia & Bureau ; Ahmed, Khan & Jafri ; Ma, Hou, Mai, Bharadwaj, Cao, Ji & Zhang ; Chu, Gong, Lin, Yuan, Cai, Gong & Luo ). Through the generation of decarboxylated S‐adenosylmethionine, methionine is a donor of the methyl group that participates in the methylation of DNA and proteins, the synthesis of spermidine and spermine and regulation of gene expression (Wu, Bazer, Wallace & Spencer ).…”

Culture Technology of Chinese Sucker (Myxocyprinusasiaticus)

“…Myxocyprinusasiaticus have small mouth diameter and high requirement for protein content in food. We choose the formula feed with diameter of 2 mm and protein content of more than 38% [7], and add water, earthworm pulp, fish surimi and mussel surimi as food attractants. We should pay attention to the freshness of the food, avoid putrefaction and deterioration of the food.…”