Attractability and palatability of liquid protein hydrolysates for Nile tilapia juveniles

Abstract

The experiment was conducted with the aim of determining the attractability and palatability of liquid protein hydrolysates for Nile tilapia. Five experimental diets were formulated containing 5% inclusion of fishmeal (FPE; positive control), 5% inclusion of liquid protein hydrolysate of porcine mucosa (PHM), 5% inclusion of liquid protein hydrolysate of poultry (PHF), 5% inclusion of liquid fish oil (OPE) and a diet without fishmeal (negative control). Five juveniles (2.51 ± 0.13 g) were distributed in 10 L tanks, and the animals were fed five times a day, with a previous draw being made of the offered diets. The same amount of pellets was offered and the following feeding behaviours were evaluated with the aid of three‐minute footages per feeding: time to capture first pellet, number of rejections, number of approaches without capturing the pellet and number of consumed pellets. None of the observed parameters displayed significant differences (p > .05), and all diets presented negative palatability indexes in comparison to FPE. The SPE diet provided a attractability and palatability index of 6.17%, while OPE index was 2.87%, PHM 2.82% and PHF 2.74%. Both PHF and PHM reduced the final consumption of pellets in comparison to FPE in approximately 28% and 20%, respectively, although it did not present significant values.

Attractivity and palatability of different hydrolysed proteins for the ornamental species Betta splendens (Regan, 1910)

“…Likewise, some other amino acids were evaluated as repulsive, such as tryptophan, arginine, threonine, methionine, phenylalanine, serine and valine (Alves, Oliveira, Luczinski, et al, 2020;Alves, Oliveira, Sosa, et al, 2020;Alves, Silva, et al, 2019;Hara, 2006Hara, , 2011Kasumyan, 1997;Kasumyan & Doving, 2003;Kasumyan & Morsi, 1996;Kasumyan & Sidorov, 2012;Lokkeborg et al, 2014;Siikavuopio et al, 2017;Suresh et al, 2011). In an amino acid profile analysis performed on the hydrolysed ingredients tested, we observed that the porcine liver hydrolysate has a higher concentration of asparagine compared with the other hydrolysed ingredients (Table 4).…”

“…Previous research has shown that each fish species is attracted to different combinations of amino acids and not all amino acids are palatable to all species (Hara, 2011; Moraes, 2016; Yacoob & Browman, 2007). There is evidence of differences between species regarding the types of amino acids that act as food stimulants or repellents, which can influence the animal's final decision (Alves, Oliveira, Luczinski, et al, 2020; Moraes, 2016; Olsen & Lundh, 2016); thus, important stimulants differ even among closely related species (Kasumyan & Doving, 2003). Kasumyan (1997) investigated 21 different fish species and the data revealed that the number of free amino acids that acted as food stimulants ranged from 0 to 13 and that in just a few fish species the number of stimulant amino acids varies by more than ten.…”

“…The attractiveness and palatability test were carried out according to the methodology described by Kasumyan and Morsi (1996); Kasumian and Doving (2003); Kasumyan and Sidorov (2012), with adaptations by Alves, Silva, et al (2019); Alves, Oliveira, et al (2019), Alves, Oliveira, Luczinski, et al, (2020); Alves, Oliveira, Sosa, et al, (2020). The authors indicated the palatability index as a quantitative estimate of taste preference (in percentage) using the following formula: PI = ((R − C)/(R + C)) × 100, where (PI) is the palatability index; (R) consumption of test feed pellets; (C) is the consumption of pellets from the control feed.…”

“…In Brazil, the poultry and swine agroindustry chain are consolidated, with a high generation of co‐products not intended for human consumption, such as viscera, feathers and giblets, which are potential raw materials for the production of ingredients such as flour, oils and protein hydrolysates at low cost (Decarli et al, 2016; Ferreira et al, 2017; Mullen et al, 2017; Silva et al, 2017). Protein hydrolysates are obtained through protein breakdown by enzymatic action or by chemical agents (Alves, Oliveira, Luczinski, et al, 2020; Alves, Oliveira, Sosa, et al, 2020; Alves, Silva, et al, 2019; Alves, Oliveira, et al, 2019; Fries et al, 2011; Passupuleti et al, 2010). There is evidence that the use of residues from animal processing, in the form of a protein hydrolysate, proves to be a potential nutritional source for animal nutrition (Feltes et al, 2010), due to providing chemical stimulants represented by free amino acids and low molecular weight peptides that influence the attractiveness and palatability.…”

“…Protein hydrolysates are obtained through protein breakdown by enzymatic action or by chemical agents (Alves, Oliveira, Luczinski, et al, 2020;Alves, Oliveira, Sosa, et al, 2020;Alves, Silva, et al, 2019;Fries et al, 2011;Passupuleti et al, 2010). There is evidence that the use of residues from animal processing, in the form of a protein hydrolysate, proves to be a potential nutritional source for animal nutrition (Feltes et al, 2010), due to providing chemical stimulants represented by free amino acids and low molecular weight peptides that influence the attractiveness and palatability.…”