Methionine Plus Cystine to Lysine Ratio in Diets for Tambaqui Juveniles

Abstract

The objective of this study was to determine the appropriate ratio of methionine plus cystine to lysine in rations for tambaqui (Colossoma macropomum) juveniles, with initial weights of 0.28 ± 0.08 g and 0.94 ± 0.33 g. A randomized block design consisting of six treatments, five replicates in two blocks, and 20 fish per replicate was implemented. Six isolisinic (1.45%), isoenergetic, isophosphoric, and isocalcic diets, containing different ratios of methionine plus cystine to digestible lysine (50%, 55%, 60%, 65%, 70%, and 75%) were used. Performance and feed efficiency variables, including body composition (moisture, protein, and fat), daily protein deposition rate, daily fat deposition rate, and nitrogen retention efficiency, were evaluated. The specific growth rate and feed conversion presented quadratic effects, with maximum effects from the digestible methionine plus cystine to lysine ratio of 64.4% and 64.8%, respectively. The increase in digestible methionine plus cystine intake resulted in a linear reduction in body fat content with the elevation of the digestible methionine plus cystine to lysine ratio. The digestible methionine plus cystine to lysine ratio recommended in rations for tambaqui fingerlings is 64.8%.

Methionine plus cystine requirements for the maintenance and efficiency of utilization with tambaqui of different body weights

“…Weight gain has been used to determine the requirement for amino acids in dose-response studies (Bomfim et al, 2020;Firmo et al, 2018;Souza et al, 2019). However, it is not considered a reliable variable to determine the requirement of amino acids for maintenance or growth, considering that fish can gain weight in the form of body protein, water, fat, and to a lesser extent minerals (Sakomura;Rostagno, 2016;Sousa et al, 2018).…”

“…Methionine is an essential amino acid for fish (National Research Council -NRC, 2011) and is generally the first limiting amino acid in many fish diets, especially those that use vegetable protein sources (Souza et al, 2019). The effect of methionine deficiency on growth and feed efficiency of fish has been demonstrated in several studies (Abidi;Khan, 2011;Tulli et al, 2010) because it participates in protein and choline synthesis and acts as a methyl group donor for nucleic acid and phospholipid substrates (Mato et al, 1997).…”

“…The amino acid requirements of fish have been determined by the dose-response method (Bomfim et al, 2020;Firmo et al, 2018;Souza et al, 2019) that evaluates the response (in function) of the increase in the test amino acid of the diet that maximizes the animal performance (Sakomura;Rostagno, 2016). However, another methodology that has gained prominence in determining the amino acid requirement in fish studies is the factorial method (Abboudi et al, 2006;He et al, 2013;Hua;Suwendi;Bureau, 2019) that determines the need for a nutrient considering the sum of the maintenance requirements plus growth and/or production (Sakomura;Rostagno, 2016).…”

Utilização De Alimentadores De Auto-Demanda: Uma Revisão E Potencial Uso Para Peixes Amazônicos

“…Abaixo encontram-se descritos três protocolos diferentes que se mostraram eficientes no treinamento alimentar de juvenis de pirarucu. Protocolo 1: Alcântara et al, (2019) avaliou o início precoce e tardio de juvenis pra transição alimentar: 2 e 4 cm de comprimento total, respectivamente. Os resultados apresentados mostram que os juvenis que iniciaram o treinamento com 4 cm tiveram melhor desempenho ao final de 30 dias após a transição alimentar (Tabela 1).…”

Aspectos Econômico Da Piscicultura Na Amazônia Brasileira

“…Com base nos aspectos morfológicos da pós-fl exão da cauda e a formação dos raios nas nadadeiras, Ruiz-Tafur et al (2017) consideram as larvas de pirarucu ao oitavo dia após a eclosão com 1,9 cm, como alevinos. Alcântara et al (2019) utilizando como referência o desenvolvimento do trato gastrointestinal de formas jovens de pirarucu, sugere que o pirarucu com aproximadamente 2 cm de comprimento estaria apto para consumir ração. Formas jovens de pirarucu criadas em diferentes temperaturas e com manejos alimentares diferentes atingem esse estágio juvenil em idades diferentes.…”