Animal and plant proteins as alternative ingredients in diets for sub‐adult olive flounder Paralichthys olivaceus at farm conditions

Abstract

A 20‐week feeding trial was performed to evaluate the optimum level of animal and plant protein sources as substitutes of fishmeal (FM) in the diets of sub‐adult olive flounder (Paralichthys olivaceus) under farmed conditions. Groups of ninety fish averaging 478 ± 4.7 g (mean ± SD) were randomly distributed into four treatments in triplicates. An FM‐based diet was used as control (CON) and three other diets replaced 20% (APP20), 30% (APP30) and 40% (APP40) of FM with animal (tankage meal and poultry by‐product meal) and plant (soy protein concentrate) protein sources. Weight gain, specific growth rate and protein efficiency ratio were not significantly different among fish fed all the experimental diets (p > 0.05). The feed efficiency of fish fed the APP40 diet was significantly lower than those of fish fed the other experimental diets (p < 0.05). Non‐specific immune responses such as superoxide dismutase activity and lysozyme activity of fish fed all the experimental diets were not significantly different (p > 0.05). Intestinal villi length of fish fed the CON diet was significantly higher than those of fish fed the other diets (p < 0.05). Based on the results of growth performances and the non‐specific immune responses, the dietary combination of animal and plant protein sources could replace up to 40% of FM in sub‐adult olive flounder.

Evaluation of Meat Meal as a Replacer for Fish Meal in Diet on Growth Performance, Feed Utilization, Chemical Composition, Hematology, and Innate Immune Responses of Olive Flounder (Paralichthys olivaceus)

“…However, neither the SOD nor lysozyme activity of olive flounder was altered by the partial dietary replacement of FM with MM in the current study, demonstrating that the replacement of FM with MM in olive flounder feed had no adverse influence on their innate immune responses. Similarly, the dietary replacement of FM with various animal and plant protein sources did not bring about any adverse impact on the immune responses of olive flounder or red sea bream [9,11,16]. Unlike this study, however, the serum SOD and lysozyme activities of tilapia (Oreochromis niloticus × O. aureus) tended to decrease with increased dietary replacement levels of FM with soybean meal because the immune system of tilapia might be influenced by the certain constituents of soybean meal [47].…”

“…Some studies [5,8] have suggested minimizing the addition of FM to fish feeds based on concerns regarding economic and environmental sustainability. Therefore, it is necessary to identify and look for a replacement that is inexpensive, readily available, and has wellbalanced AA profiles for FM in fish feeds [9,10]. Recently, there has been an increasing number of studies on a novel substitute for FM in fish feeds and research will continue to expand worldwide.…”

“…Recently, there has been an increasing number of studies on a novel substitute for FM in fish feeds and research will continue to expand worldwide. There has been growing interest in using various animal and plant sources in fish feeds to alleviate the pressure from FM usage [9,[11][12][13]. Nevertheless, when utilized as sources of protein for fish diets, most plant protein sources have several issues, including imbalanced AA, declined palatability, as well as a variety of antinutritional factors [5,6,14].…”

“…Meat meal (MM) is a by-product meal generated by slaughterhouses or meat processing plants from land animals. It is not only rich in protein but also reasonable in price, and has been widely used in the production of various fish diets during the last few decades [9,[15][16][17][18][19][20]. Therefore, it is predicted that feed costs could be lowered by replacing FM with MM in the diets of olive flounder and other carnivorous fish species.…”

Assessment of Various Biochar Sources as a Dietary Additive in Cirrhinus mrigala Fingerlings to Enhance Mineral Status, Carcass Composition, and Antioxidant Activity

“…In this method, transportation costs might be avoided, which would lower costs and perhaps promotes both environmental and economic sustainability. To ease the strain from the use of fishmeal, there has been an increase of interest in employing alternative plant sources in fish feed (Choi et al, 2022). Plant-based ingredients are widely utilized in fish diets because they are more readily available and less expensive than fishmeal (Sarfraz et al, 2020).…”