Effects of protein-, peptide- and free amino acid-based diets in fish nutrition

Abstract

In the present review, we summarize data related to the utilization of purified diets formulated with the purpose of determining the amino acid requirements in fish independent of the ontogenetic stage and the morphological characteristics of the digestive tract. Expanding present knowledge on the formulation of protein, free amino acid (FAA) and synthetic dipeptide‐based diets can provide possible insights that might lead to a better understanding of the mechanism of amino acid utilization in the growth of fish. Differences exist in the utilization of protein, dipeptides or free amino acids for growth between stomach‐possessing and stomachless fish with respect to their response to manipulating the proportion of protein and dipeptides in the formulas. Free amino acid‐based diets are uniformly inferior. The effects of diet manipulation on indispensable FAA concentrations in the body (muscle) are not simply the result of deamination or the protein synthesis/degradation ratio. The hydroxyproline/proline ratio was confirmed to be of value in quantifying muscle collagen degradation/synthesis and can perhaps be used to quantify the amino acid requirement necessary to maximize the utilization (deposition) of dietary amino acids. In summary, indispensable amino acid requirements for maximum growth in fish can be addressed using diets formulated from protein/peptide/FAA sources.

Inclusion of camelina meal as a protein source in diets for farmed salmonids

“…It is possible that the lysine added to the diets was not well absorbed by salmon, as crystalline amino acids may be absorbed at a different rate than protein-bound amino acids, which can reduce the efficiency of uptake (Peres & Oliva-Teles 2005) and ultimately affect the growth performance (Dabrowski et al 2010). Weight gain and specific growth rate are centred in the plot and closely located to glycine, tyrosine, leucine and 16:1n-7.…”

Effective replacement of protein-bound amino acids by crystalline amino acids in Senegalese sole (Solea senegalensis) juveniles

“…; Dabrowski et al . ). This was attributed to differences in free AA and protein‐bound AA absorption rates in the intestine or leaching of AA from the feed (Peres & Oliva‐Teles ).…”

“…However, similarly to the present study, a dietary replacement of protein-bound by crystalline-AA up to 45% in gilthead seabream (Marcouli et al 2004) or 50% in rainbow trout (Rodehutscord et al 1995;Bodin et al 2012) was achievable without affecting fish . performances. Differently, other studies in fish indicated that comparatively with protein-bound amino acids including crystalline-AA in diet formulation negatively affects fish performance (Cowey 1992;Zarate & Lovell 1997;El-Haroun & Bureau 2007;Hauler et al 2007;Dabrowski et al 2010). This was attributed to differences in free AA and protein-bound AA absorption rates in the intestine or leaching of AA from the feed (Peres & Oliva-Teles 2005).…”

Effects of fishmeal replacement with cottonseed meal protein hydrolysate on growth, digestion and intestinal histology of juvenile Chinese soft-shelled turtle,Pelodiscus sinensis

“…In our study, the FCR increased and PER reduced while the supplement levels of CPH improved in diets. Studies have shown that gastrointestinal absorption rate asynchronism between free amino acids and protein‐bound amino acids can lead to the lower bio‐efficacy values of free amino acids contained in protein hydrolysate (Ambardekar, Reigh, & Williams, ; Bodin et al., ; Dabrowski, Zhang, Kwasek, Hliwa, & Ostaszewska, ; Espe, Lied, & Torrissen, ; Espe, Sveier, Høgøy, & Lied, ; Nunes, Sá, Browdy, & Vazquez‐Anon, ; Zarate, Lovell, & Payne, ), whereas the reduction in feed utilization could be offset to some extent with an increase in FI. The present study showed a significant enhancement of FI in turtle fed with diet CPH15.…”