Effects of phosphorylated protein concentrate of pumpkin seed meal on growth and digestive enzymes activity of silver catfish (Rhamdia quelen)

Abstract

The present study aimed to determine the growth and activity of proteolytic digestive enzymes of silver catfish (Rhamdia quelen) fed by replacing increased fish meal in the diet by either phosphorylated protein concentrate or pumpkin seed meal (PPCPS). Five experimental diets were formulated with levels: 0 (control), 25 (25% pumpkin seed meal (PSM) and 25% PPCPS) and 50% (50% PSM and 50% PPCPS). Crude protein from fish meal was replaced either by PSM or PPCPS crude protein. Each diet was fed to four replicate groups of silver catfish (initial weight 24 ± 0.46 g) to apparent satiation three times a day. Four orthogonal contrasts were applied to the biological assay data. When compared to other diets, the replacement of fish meal by either 25% or 50% of PPCPS in the diet of juvenile catfish does not change growth rates and promotes improvement in feed conversion. The use of PSM as a protein ingredient is not recommended due to its negative influence on fish growth. Thus, it can be concluded that the nutritional value of PSM can be improved by the simple chemical process of phosphorylation, yielding a protein concentrate (PPCPS) that may be used as a promising alternative ingredient.

Fish meal replaced by hydrolysed soybean meal in diets increases growth and improves the antioxidant defense system of silver catfish ( Rhamdia quelen )

“…The provision of diets containing up to 20% of HSM improved the growth of silver catfish without impairing food efficiency. Silver catfish is able to take advantage of different plant protein sources in the diet (Dalcin et al, ; Gourlat et al, ; Lovatto et al, ). High inclusion levels of plant protein sources in the diets leads to deficiency of essential amino acids and may compromise growth (Gatlin et al, ).…”

Effect of replacing fish meal by full fat soybean meal on growth performance, feed utilization and gastrointestinal enzymes in diets for African catfish Clarias gariepinus

“…in the catfish intestine optimum pH ranged between 8.5 to 10 Also, the catfish stomach showed optimum proteolytic activity at pH 3.0 and 4.0 however, Abdel-Warith et al (2013) reported that the data obtained of tilapia showed optimum proteolytic activity in tilapia intestine was at pH 7.0-8.5, whereas, in the stomach was at pH 1.5-3.0, this gives an indicator that in thick-walled muscular stomachs, such as C. gariepinus, the pH is quite high at around 4. Lovatto et al (2017) argued that higher trypsin activity in silver catfish (Rhamdia quelen) fed diets containing pumpkin seed meal represents the body's attempt to increase the digestibility of protein, that adverse in increased activities of the proteolytic. Alarcon et al (2001) who found that the connection between the trypsin activities in the intestinal and the digestibility of protein in L. argentiventris and L. novemfasciatus, inhibitor activity of the enzyme appears to be offset by raising the secretion of enzymes proteolytic and increased protein absorption in distal parts of the intestine.…”

“…These digestive enzymes, like others, are active into the proximal intestine. The hydrolysis of protein intake from the diets which occurs by these enzymes that active in the proximal intestine, serve to break down the protein to simple molecules that can then be absorbed throughout the intestine and used in the metabolic process (Lovatto et al, 2017). While some studies have focused their attention on the influence of different substitute plant proteins on fish growth and feed utilization, few have looked at how diet changes the activities of digestive enzymes) Xu et al (2012) and Zhao et al (2016).…”

Effects of rice bran protein concentrate on the growth performance and digestive enzyme activities of jundiá ( Rhamdia quelen ) (Quoy and Gaimard, 1824)

“…In general, the use of plant protein concentrates in fish diets results in a reduced activity of trypsin (Krogdahl, Bakke‐Mckellep, & Baeverfjord, ), which is caused by the presence of antinutritional factors (Pavasovic, Anderson, Mather, & Richardson, ). However, the occurrence of increased enzyme activity is explained by the body's attempt to enhance the digestibility of the ingested protein, reflecting a higher proteolytic activity (Lovatto et al, ). However, the results found in this study showed that the trypsin and chymotrypsin enzyme activities were not affected by the dietary inclusion of RBPC.…”

“…Chemical and enzymatic methods can also be used to improve protein digestibility, reduce fibre content and increase the amino acid content of plant protein sources (Lovatto et al, ). By reducing the fibre content, the amino acid level and crude protein level also increased in the raw material (Palmegiano et al, ).…”